[ovs-dev,v2,06/18] northd: Add a new engine 'lr-lb-nat-data' to manage routers' lb data.

From: Numan Siddique <numans@ovn.org>

This new engine now maintains the load balancer and NAT data of a
logical router which was earlier part of northd engine node data.
The main inputs to this engine are:
   - northd node
   - lr-nat node

A record for each logical router is maintained in the 'lr_lb_nats'
hmap table and this record
   - stores the lb related data
   - embeds the 'lr-nat' record.

This engine node becomes an input to 'lflow' node.

Signed-off-by: Numan Siddique <numans@ovn.org>
---
 lib/stopwatch-names.h      |   1 +
 northd/automake.mk         |   2 +
 northd/en-lflow.c          |   4 +
 northd/en-lr-lb-nat-data.c | 654 +++++++++++++++++++++++++++++++++++++
 northd/en-lr-lb-nat-data.h |  93 ++++++
 northd/en-lr-nat.h         |   3 +
 northd/en-sync-sb.c        |  50 +--
 northd/inc-proc-northd.c   |  13 +-
 northd/northd.c            | 640 ++++++++++++------------------------
 northd/northd.h            | 137 +++++++-
 tests/ovn-northd.at        | 110 +++++--
 11 files changed, 1212 insertions(+), 495 deletions(-)
 create mode 100644 northd/en-lr-lb-nat-data.c
 create mode 100644 northd/en-lr-lb-nat-data.h

On Thu, Oct 26, 2023 at 11:16 AM <numans@ovn.org> wrote:
>
> From: Numan Siddique <numans@ovn.org>
>
> This new engine now maintains the load balancer and NAT data of a
> logical router which was earlier part of northd engine node data.
> The main inputs to this engine are:
>    - northd node
>    - lr-nat node

nit: According to the implementation, the node has lb_data as input, too.

Thanks,
Han

>
> A record for each logical router is maintained in the 'lr_lb_nats'
> hmap table and this record
>    - stores the lb related data
>    - embeds the 'lr-nat' record.
>
> This engine node becomes an input to 'lflow' node.
>
> Signed-off-by: Numan Siddique <numans@ovn.org>
> ---
>  lib/stopwatch-names.h      |   1 +
>  northd/automake.mk         |   2 +
>  northd/en-lflow.c          |   4 +
>  northd/en-lr-lb-nat-data.c | 654 +++++++++++++++++++++++++++++++++++++
>  northd/en-lr-lb-nat-data.h |  93 ++++++
>  northd/en-lr-nat.h         |   3 +
>  northd/en-sync-sb.c        |  50 +--
>  northd/inc-proc-northd.c   |  13 +-
>  northd/northd.c            | 640 ++++++++++++------------------------
>  northd/northd.h            | 137 +++++++-
>  tests/ovn-northd.at        | 110 +++++--
>  11 files changed, 1212 insertions(+), 495 deletions(-)
>  create mode 100644 northd/en-lr-lb-nat-data.c
>  create mode 100644 northd/en-lr-lb-nat-data.h
>
> diff --git a/lib/stopwatch-names.h b/lib/stopwatch-names.h
> index 0a16da211e..7d85acdaea 100644
> --- a/lib/stopwatch-names.h
> +++ b/lib/stopwatch-names.h
> @@ -33,5 +33,6 @@
>  #define PORT_GROUP_RUN_STOPWATCH_NAME "port_group_run"
>  #define SYNC_METERS_RUN_STOPWATCH_NAME "sync_meters_run"
>  #define LR_NAT_RUN_STOPWATCH_NAME "lr_nat_run"
> +#define LR_LB_NAT_DATA_RUN_STOPWATCH_NAME "lr_lb_nat_data"
>
>  #endif
> diff --git a/northd/automake.mk b/northd/automake.mk
> index ae367a2a8b..4116c487df 100644
> --- a/northd/automake.mk
> +++ b/northd/automake.mk
> @@ -26,6 +26,8 @@ northd_ovn_northd_SOURCES = \
>         northd/en-lb-data.h \
>         northd/en-lr-nat.c \
>         northd/en-lr-nat.h \
> +       northd/en-lr-lb-nat-data.c \
> +       northd/en-lr-lb-nat-data.h \
>         northd/inc-proc-northd.c \
>         northd/inc-proc-northd.h \
>         northd/ipam.c \
> diff --git a/northd/en-lflow.c b/northd/en-lflow.c
> index 22f398d419..9cb0ead3f0 100644
> --- a/northd/en-lflow.c
> +++ b/northd/en-lflow.c
> @@ -20,6 +20,7 @@
>
>  #include "en-lflow.h"
>  #include "en-lr-nat.h"
> +#include "en-lr-lb-nat-data.h"
>  #include "en-northd.h"
>  #include "en-meters.h"
>
> @@ -43,6 +44,8 @@ lflow_get_input_data(struct engine_node *node,
>          engine_get_input_data("sync_meters", node);
>      struct ed_type_lr_nat_data *lr_nat_data =
>          engine_get_input_data("lr_nat", node);
> +    struct ed_type_lr_lb_nat_data *lr_lb_nat_data =
> +        engine_get_input_data("lr_lb_nat_data", node);
>
>      lflow_input->nbrec_bfd_table =
>          EN_OVSDB_GET(engine_get_input("NB_bfd", node));
> @@ -66,6 +69,7 @@ lflow_get_input_data(struct engine_node *node,
>      lflow_input->lr_ports = &northd_data->lr_ports;
>      lflow_input->ls_port_groups = &pg_data->ls_port_groups;
>      lflow_input->lr_nats = &lr_nat_data->lr_nats;
> +    lflow_input->lr_lbnats = &lr_lb_nat_data->lr_lbnats;
>      lflow_input->meter_groups = &sync_meters_data->meter_groups;
>      lflow_input->lb_datapaths_map = &northd_data->lb_datapaths_map;
>      lflow_input->svc_monitor_map = &northd_data->svc_monitor_map;
> diff --git a/northd/en-lr-lb-nat-data.c b/northd/en-lr-lb-nat-data.c
> new file mode 100644
> index 0000000000..19b638ce0b
> --- /dev/null
> +++ b/northd/en-lr-lb-nat-data.c
> @@ -0,0 +1,654 @@
> +/*
> + * Copyright (c) 2023, Red Hat, Inc.
> + *
> + * Licensed under the Apache License, Version 2.0 (the "License");
> + * you may not use this file except in compliance with the License.
> + * You may obtain a copy of the License at:
> + *
> + *     http://www.apache.org/licenses/LICENSE-2.0
> + *
> + * Unless required by applicable law or agreed to in writing, software
> + * distributed under the License is distributed on an "AS IS" BASIS,
> + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
implied.
> + * See the License for the specific language governing permissions and
> + * limitations under the License.
> + */
> +
> +#include <config.h>
> +
> +#include <getopt.h>
> +#include <stdlib.h>
> +#include <stdio.h>
> +
> +/* OVS includes */
> +#include "include/openvswitch/hmap.h"
> +#include "lib/bitmap.h"
> +#include "lib/socket-util.h"
> +#include "lib/uuidset.h"
> +#include "openvswitch/util.h"
> +#include "openvswitch/vlog.h"
> +#include "stopwatch.h"
> +
> +/* OVN includes */
> +#include "en-lb-data.h"
> +#include "en-lr-lb-nat-data.h"
> +#include "en-lr-nat.h"
> +#include "lib/inc-proc-eng.h"
> +#include "lib/lb.h"
> +#include "lib/ovn-nb-idl.h"
> +#include "lib/ovn-sb-idl.h"
> +#include "lib/ovn-util.h"
> +#include "lib/stopwatch-names.h"
> +#include "northd.h"
> +
> +VLOG_DEFINE_THIS_MODULE(en_lr_lb_nat_data);
> +
> +/* Static function declarations. */
> +static void lr_lb_nat_data_table_init(struct lr_lb_nat_data_table *);
> +static void lr_lb_nat_data_table_clear(struct lr_lb_nat_data_table *);
> +static void lr_lb_nat_data_table_destroy(struct lr_lb_nat_data_table *);
> +static struct lr_lb_nat_data_record *lr_lb_nat_data_table_find_(
> +    const struct lr_lb_nat_data_table *, const struct
nbrec_logical_router *);
> +static struct lr_lb_nat_data_record *lr_lb_nat_data_table_find_by_index_(
> +    const struct lr_lb_nat_data_table *table, size_t od_index);
> +
> +static void lr_lb_nat_data_table_build(struct lr_lb_nat_data_table *,
> +                                   const struct lr_nat_table *,
> +                                   const struct ovn_datapaths
*lr_datapaths,
> +                                   const struct hmap *lb_datapaths_map,
> +                                   const struct hmap
*lbgrp_datapaths_map);
> +
> +static struct lr_lb_nat_data_input lr_lb_nat_data_get_input_data(
> +    struct engine_node *);
> +
> +static struct lr_lb_nat_data_record *lr_lb_nat_data_record_create(
> +    struct lr_lb_nat_data_table *, const struct lr_nat_record *,
> +    const struct hmap *lb_datapaths_map,
> +    const struct hmap *lbgrp_datapaths_map);
> +static void lr_lb_nat_data_record_destroy(struct lr_lb_nat_data_record
*);
> +static void lr_lb_nat_data_record_init(
> +    struct lr_lb_nat_data_record *,
> +    const struct hmap *lb_datapaths_map,
> +    const struct hmap *lbgrp_datapaths_map);
> +
> +static void build_lrouter_lb_reachable_ips(struct lr_lb_nat_data_record
*,
> +                                           const struct ovn_northd_lb *);
> +static void add_neigh_ips_to_lrouter(struct lr_lb_nat_data_record *,
> +                                     enum lb_neighbor_responder_mode,
> +                                     const struct sset *lb_ips_v4,
> +                                     const struct sset *lb_ips_v6);
> +static void remove_lrouter_lb_reachable_ips(struct lr_lb_nat_data_record
*,
> +                                            enum
lb_neighbor_responder_mode,
> +                                            const struct sset *lb_ips_v4,
> +                                            const struct sset
*lb_ips_v6);
> +static void lr_lb_nat_data_build_vip_nats(struct lr_lb_nat_data_record
*);
> +
> +/* 'lr_lb_nat_data' engine node manages the NB logical router LB data.
> + */
> +void *
> +en_lr_lb_nat_data_init(struct engine_node *node OVS_UNUSED,
> +               struct engine_arg *arg OVS_UNUSED)
> +{
> +    struct ed_type_lr_lb_nat_data *data = xzalloc(sizeof *data);
> +    lr_lb_nat_data_table_init(&data->lr_lbnats);
> +    hmapx_init(&data->tracked_data.crupdated);
> +    hmapx_init(&data->tracked_data.deleted);
> +    return data;
> +}
> +
> +void
> +en_lr_lb_nat_data_cleanup(void *data_)
> +{
> +    struct ed_type_lr_lb_nat_data *data =
> +        (struct ed_type_lr_lb_nat_data *) data_;
> +    lr_lb_nat_data_table_destroy(&data->lr_lbnats);
> +    hmapx_destroy(&data->tracked_data.crupdated);
> +    hmapx_destroy(&data->tracked_data.deleted);
> +}
> +
> +void
> +en_lr_lb_nat_data_clear_tracked_data(void *data_)
> +{
> +    struct ed_type_lr_lb_nat_data *data =
> +        (struct ed_type_lr_lb_nat_data *) data_;
> +
> +    struct hmapx_node *hmapx_node;
> +    HMAPX_FOR_EACH_SAFE (hmapx_node, &data->tracked_data.deleted) {
> +        lr_lb_nat_data_record_destroy(hmapx_node->data);
> +        hmapx_delete(&data->tracked_data.deleted, hmapx_node);
> +    }
> +
> +    hmapx_clear(&data->tracked_data.crupdated);
> +    data->tracked = false;
> +}
> +
> +void
> +en_lr_lb_nat_data_run(struct engine_node *node, void *data_)
> +{
> +    struct lr_lb_nat_data_input input_data =
> +        lr_lb_nat_data_get_input_data(node);
> +    struct ed_type_lr_lb_nat_data *data = data_;
> +
> +    stopwatch_start(LR_LB_NAT_DATA_RUN_STOPWATCH_NAME, time_msec());
> +
> +    lr_lb_nat_data_table_clear(&data->lr_lbnats);
> +    lr_lb_nat_data_table_build(&data->lr_lbnats, input_data.lr_nats,
> +                               input_data.lr_datapaths,
> +                               input_data.lb_datapaths_map,
> +                               input_data.lbgrp_datapaths_map);
> +
> +    stopwatch_stop(LR_LB_NAT_DATA_RUN_STOPWATCH_NAME, time_msec());
> +    engine_set_node_state(node, EN_UPDATED);
> +}
> +
> +bool
> +lr_lb_nat_data_northd_handler(struct engine_node *node, void *data
OVS_UNUSED)
> +{
> +    struct northd_data *northd_data = engine_get_input_data("northd",
node);
> +    if (!northd_data->change_tracked) {
> +        return false;
> +    }
> +
> +    return true;
> +}
> +
> +bool
> +lr_lb_nat_data_lb_data_handler(struct engine_node *node, void *data_)
> +{
> +    struct ed_type_lb_data *lb_data = engine_get_input_data("lb_data",
node);
> +    if (!lb_data->tracked) {
> +        return false;
> +    }
> +
> +    struct ed_type_lr_lb_nat_data *data =
> +        (struct ed_type_lr_lb_nat_data *) data_;
> +    struct lr_lb_nat_data_input input_data =
> +        lr_lb_nat_data_get_input_data(node);
> +    struct lr_lb_nat_data_record *lr_lbnat_rec;
> +    size_t index;
> +
> +    const struct tracked_lb_data *trk_lb_data =
&lb_data->tracked_lb_data;
> +    const struct ovn_lb_group_datapaths *lbgrp_dps;
> +    const struct crupdated_lbgrp *crupdated_lbgrp;
> +    const struct crupdated_od_lb_data *codlb;
> +    const struct ovn_lb_datapaths *lb_dps;
> +    const struct crupdated_lb *clb;
> +    const struct ovn_northd_lb *lb;
> +    const struct ovn_datapath *od;
> +
> +    LIST_FOR_EACH (codlb, list_node, &trk_lb_data->crupdated_lr_lbs) {
> +        od = ovn_datapath_find(&input_data.lr_datapaths->datapaths,
> +                               &codlb->od_uuid);
> +        ovs_assert(od);
> +
> +        lr_lbnat_rec = lr_lb_nat_data_table_find_(&data->lr_lbnats,
od->nbr);
> +        if (!lr_lbnat_rec) {
> +            const struct lr_nat_record *lrnat_rec =
lr_nat_table_find_by_index(
> +                input_data.lr_nats, od->index);
> +            ovs_assert(lrnat_rec);
> +
> +            lr_lbnat_rec = lr_lb_nat_data_record_create(&data->lr_lbnats,
> +                                            lrnat_rec,
> +                                            input_data.lb_datapaths_map,
> +
 input_data.lbgrp_datapaths_map);
> +
> +            /* Add the lr_lbnat_rec rec to the tracking data. */
> +            hmapx_add(&data->tracked_data.crupdated, lr_lbnat_rec);
> +            continue;
> +        }
> +
> +        struct uuidset_node *uuidnode;
> +        UUIDSET_FOR_EACH (uuidnode, &codlb->assoc_lbs) {
> +            lb_dps = ovn_lb_datapaths_find(
> +                input_data.lb_datapaths_map, &uuidnode->uuid);
> +            ovs_assert(lb_dps);
> +
> +            /* Add the lb_ips of lb_dps to the od. */
> +            build_lrouter_lb_ips(lr_lbnat_rec->lb_ips, lb_dps->lb);
> +            build_lrouter_lb_reachable_ips(lr_lbnat_rec, lb_dps->lb);
> +        }
> +
> +        UUIDSET_FOR_EACH (uuidnode, &codlb->assoc_lbgrps) {
> +            lbgrp_dps = ovn_lb_group_datapaths_find(
> +                input_data.lbgrp_datapaths_map, &uuidnode->uuid);
> +            ovs_assert(lbgrp_dps);
> +
> +            for (size_t j = 0; j < lbgrp_dps->lb_group->n_lbs; j++) {
> +                const struct uuid *lb_uuid
> +                    = &lbgrp_dps->lb_group->lbs[j]->nlb->header_.uuid;
> +                lb_dps =
ovn_lb_datapaths_find(input_data.lb_datapaths_map,
> +                                               lb_uuid);
> +                ovs_assert(lb_dps);
> +
> +                /* Add the lb_ips of lb_dps to the od. */
> +                build_lrouter_lb_ips(lr_lbnat_rec->lb_ips, lb_dps->lb);
> +                build_lrouter_lb_reachable_ips(lr_lbnat_rec, lb_dps->lb);
> +            }
> +        }
> +
> +        /* Add the lr_lbnat_rec rec to the tracking data. */
> +        hmapx_add(&data->tracked_data.crupdated, lr_lbnat_rec);
> +    }
> +
> +    HMAP_FOR_EACH (clb, hmap_node, &trk_lb_data->crupdated_lbs) {
> +        lb = clb->lb;
> +        const struct uuid *lb_uuid = &lb->nlb->header_.uuid;
> +
> +        lb_dps = ovn_lb_datapaths_find(input_data.lb_datapaths_map,
lb_uuid);
> +        ovs_assert(lb_dps);
> +
> +        BITMAP_FOR_EACH_1 (index, ods_size(input_data.lr_datapaths),
> +                           lb_dps->nb_lr_map) {
> +            od = input_data.lr_datapaths->array[index];
> +
> +            lr_lbnat_rec = lr_lb_nat_data_table_find_(&data->lr_lbnats,
> +                                                      od->nbr);
> +            ovs_assert(lr_lbnat_rec);
> +
> +            /* Update the od->lb_ips with the deleted and inserted
> +             * vips (if any). */
> +            remove_ips_from_lb_ip_set(lr_lbnat_rec->lb_ips, lb->routable,
> +                                      &clb->deleted_vips_v4,
> +                                      &clb->deleted_vips_v6);
> +            add_ips_to_lb_ip_set(lr_lbnat_rec->lb_ips, lb->routable,
> +                                 &clb->inserted_vips_v4,
> +                                 &clb->inserted_vips_v6);
> +
> +            remove_lrouter_lb_reachable_ips(lr_lbnat_rec, lb->neigh_mode,
> +                                            &clb->deleted_vips_v4,
> +                                            &clb->deleted_vips_v6);
> +            add_neigh_ips_to_lrouter(lr_lbnat_rec, lb->neigh_mode,
> +                                     &clb->inserted_vips_v4,
> +                                     &clb->inserted_vips_v6);
> +
> +            /* Add the lr_lbnat_rec rec to the tracking data. */
> +            hmapx_add(&data->tracked_data.crupdated, lr_lbnat_rec);
> +        }
> +    }
> +
> +    HMAP_FOR_EACH (crupdated_lbgrp, hmap_node,
> +                   &trk_lb_data->crupdated_lbgrps) {
> +        const struct uuid *lb_uuid = &crupdated_lbgrp->lbgrp->uuid;
> +
> +        lbgrp_dps =
ovn_lb_group_datapaths_find(input_data.lbgrp_datapaths_map,
> +                                                lb_uuid);
> +        ovs_assert(lbgrp_dps);
> +
> +        struct hmapx_node *hnode;
> +        HMAPX_FOR_EACH (hnode, &crupdated_lbgrp->assoc_lbs) {
> +            lb = hnode->data;
> +            lb_uuid = &lb->nlb->header_.uuid;
> +            lb_dps = ovn_lb_datapaths_find(input_data.lb_datapaths_map,
> +                                           lb_uuid);
> +            ovs_assert(lb_dps);
> +            for (size_t i = 0; i < lbgrp_dps->n_lr; i++) {
> +                od = lbgrp_dps->lr[i];
> +                lr_lbnat_rec =
lr_lb_nat_data_table_find_(&data->lr_lbnats,
> +                                                          od->nbr);
> +                ovs_assert(lr_lbnat_rec);
> +                /* Add the lb_ips of lb_dps to the lr lb data. */
> +                build_lrouter_lb_ips(lr_lbnat_rec->lb_ips, lb_dps->lb);
> +                build_lrouter_lb_reachable_ips(lr_lbnat_rec, lb_dps->lb);
> +
> +                /* Add the lr_lbnat_rec rec to the tracking data. */
> +                hmapx_add(&data->tracked_data.crupdated, lr_lbnat_rec);
> +            }
> +        }
> +    }
> +
> +    if (!hmapx_is_empty(&data->tracked_data.crupdated)) {
> +        struct hmapx_node *hmapx_node;
> +        /* For all the modified lr_lb_nat_data records (re)build the
> +         * vip nats. */
> +        HMAPX_FOR_EACH (hmapx_node, &data->tracked_data.crupdated) {
> +            lr_lb_nat_data_build_vip_nats(hmapx_node->data);
> +        }
> +
> +        data->tracked = true;
> +        engine_set_node_state(node, EN_UPDATED);
> +    }
> +
> +    return true;
> +}
> +
> +bool
> +lr_lb_nat_data_lr_nat_handler(struct engine_node *node, void *data_)
> +{
> +    struct ed_type_lr_nat_data *lr_nat_data =
> +        engine_get_input_data("lr_nat", node);
> +
> +    if (!lr_nat_data->tracked
> +        || !hmapx_is_empty(&lr_nat_data->tracked_data.deleted)) {
> +        return false;
> +    }
> +
> +    struct ed_type_lr_lb_nat_data *data =
> +        (struct ed_type_lr_lb_nat_data *) data_;
> +    struct lr_lb_nat_data_input input_data =
> +        lr_lb_nat_data_get_input_data(node);
> +    const struct lr_nat_record *lrnat_rec;
> +    struct lr_lb_nat_data_record *lr_lbnat_rec;
> +    struct hmapx_node *hmapx_node;
> +
> +    HMAPX_FOR_EACH (hmapx_node, &lr_nat_data->tracked_data.crupdated) {
> +        lrnat_rec = hmapx_node->data;
> +        lr_lbnat_rec = lr_lb_nat_data_table_find_(&data->lr_lbnats,
> +                                                  lrnat_rec->od->nbr);
> +        if (!lr_lbnat_rec) {
> +            lr_lbnat_rec = lr_lb_nat_data_record_create(&data->lr_lbnats,
> +                                            lrnat_rec,
> +                                            input_data.lb_datapaths_map,
> +
 input_data.lbgrp_datapaths_map);
> +        } else {
> +            lr_lb_nat_data_build_vip_nats(lr_lbnat_rec);
> +        }
> +
> +        /* Add the lr_lbnat_rec rec to the tracking data. */
> +        hmapx_add(&data->tracked_data.crupdated, lr_lbnat_rec);
> +    }
> +
> +    if (!hmapx_is_empty(&data->tracked_data.crupdated)) {
> +        data->tracked = true;
> +        engine_set_node_state(node, EN_UPDATED);
> +    }
> +
> +    return true;
> +}
> +
> +const struct lr_lb_nat_data_record *
> +lr_lb_nat_data_table_find_by_index(const struct lr_lb_nat_data_table
*table,
> +                                   size_t od_index)
> +{
> +    return lr_lb_nat_data_table_find_by_index_(table, od_index);
> +}
> +
> +/* static functions. */
> +static void
> +lr_lb_nat_data_table_init(struct lr_lb_nat_data_table *table)
> +{
> +    *table = (struct lr_lb_nat_data_table) {
> +        .entries = HMAP_INITIALIZER(&table->entries),
> +    };
> +}
> +
> +static void
> +lr_lb_nat_data_table_destroy(struct lr_lb_nat_data_table *table)
> +{
> +    lr_lb_nat_data_table_clear(table);
> +    hmap_destroy(&table->entries);
> +}
> +
> +static void
> +lr_lb_nat_data_table_clear(struct lr_lb_nat_data_table *table)
> +{
> +    struct lr_lb_nat_data_record *lr_lbnat_rec;
> +    HMAP_FOR_EACH_POP (lr_lbnat_rec, key_node, &table->entries) {
> +        lr_lb_nat_data_record_destroy(lr_lbnat_rec);
> +    }
> +
> +    free(table->array);
> +    table->array = NULL;
> +}
> +
> +static void
> +lr_lb_nat_data_table_build(struct lr_lb_nat_data_table *table,
> +                       const struct lr_nat_table *lr_nats,
> +                       const struct ovn_datapaths *lr_datapaths,
> +                       const struct hmap *lb_datapaths_map,
> +                       const struct hmap *lbgrp_datapaths_map)
> +{
> +    table->array = xrealloc(table->array,
> +                            ods_size(lr_datapaths) * sizeof
*table->array);
> +    const struct lr_nat_record *lrnat_rec;
> +    LR_NAT_TABLE_FOR_EACH (lrnat_rec, lr_nats) {
> +        lr_lb_nat_data_record_create(table, lrnat_rec, lb_datapaths_map,
> +                                     lbgrp_datapaths_map);
> +    }
> +}
> +
> +static struct lr_lb_nat_data_record *
> +lr_lb_nat_data_table_find_(const struct lr_lb_nat_data_table *table,
> +                  const struct nbrec_logical_router *nbr)
> +{
> +    struct lr_lb_nat_data_record *lr_lbnat_rec;
> +
> +    HMAP_FOR_EACH_WITH_HASH (lr_lbnat_rec, key_node,
> +                             uuid_hash(&nbr->header_.uuid),
&table->entries) {
> +        if (nbr == lr_lbnat_rec->od->nbr) {
> +            return lr_lbnat_rec;
> +        }
> +    }
> +    return NULL;
> +}
> +
> +static struct lr_lb_nat_data_record *
> +lr_lb_nat_data_table_find_by_index_(const struct lr_lb_nat_data_table
*table,
> +                                   size_t od_index)
> +{
> +    ovs_assert(od_index <= hmap_count(&table->entries));
> +    return table->array[od_index];
> +}
> +
> +static struct lr_lb_nat_data_record *
> +lr_lb_nat_data_record_create(struct lr_lb_nat_data_table *table,
> +                         const struct lr_nat_record *lrnat_rec,
> +                         const struct hmap *lb_datapaths_map,
> +                         const struct hmap *lbgrp_datapaths_map)
> +{
> +    struct lr_lb_nat_data_record *lr_lbnat_rec = xzalloc(sizeof
*lr_lbnat_rec);
> +    lr_lbnat_rec->lrnat_rec = lrnat_rec;
> +    lr_lbnat_rec->od = lrnat_rec->od;
> +    lr_lb_nat_data_record_init(lr_lbnat_rec, lb_datapaths_map,
> +                               lbgrp_datapaths_map);
> +
> +    hmap_insert(&table->entries, &lr_lbnat_rec->key_node,
> +                uuid_hash(&lr_lbnat_rec->od->nbr->header_.uuid));
> +
> +    table->array[lr_lbnat_rec->od->index] = lr_lbnat_rec;
> +    return lr_lbnat_rec;
> +}
> +
> +static void
> +lr_lb_nat_data_record_destroy(struct lr_lb_nat_data_record *lr_lbnat_rec)
> +{
> +    ovn_lb_ip_set_destroy(lr_lbnat_rec->lb_ips);
> +    lr_lbnat_rec->lb_ips = NULL;
> +    sset_destroy(&lr_lbnat_rec->vip_nats);
> +    free(lr_lbnat_rec);
> +}
> +
> +static void
> +lr_lb_nat_data_record_init(struct lr_lb_nat_data_record *lr_lbnat_rec,
> +                           const struct hmap *lb_datapaths_map,
> +                           const struct hmap *lbgrp_datapaths_map)
> +{
> +    const struct nbrec_load_balancer_group *nbrec_lb_group;
> +    const struct ovn_lb_group_datapaths *lb_group_dps;
> +    const struct ovn_lb_datapaths *lb_dps;
> +
> +    /* Checking load balancer groups first, starting from the largest
one,
> +     * to more efficiently copy IP sets. */
> +    size_t largest_group = 0;
> +
> +    const struct nbrec_logical_router *nbr = lr_lbnat_rec->od->nbr;
> +    for (size_t i = 1; i < nbr->n_load_balancer_group; i++) {
> +        if (nbr->load_balancer_group[i]->n_load_balancer >
> +
 nbr->load_balancer_group[largest_group]->n_load_balancer) {
> +            largest_group = i;
> +        }
> +    }
> +
> +    for (size_t i = 0; i < nbr->n_load_balancer_group; i++) {
> +        size_t idx = (i + largest_group) % nbr->n_load_balancer_group;
> +
> +        nbrec_lb_group = nbr->load_balancer_group[idx];
> +        const struct uuid *lbgrp_uuid = &nbrec_lb_group->header_.uuid;
> +
> +        lb_group_dps =
> +            ovn_lb_group_datapaths_find(lbgrp_datapaths_map,
> +                                        lbgrp_uuid);
> +        ovs_assert(lb_group_dps);
> +
> +        if (!lr_lbnat_rec->lb_ips) {
> +            lr_lbnat_rec->lb_ips =
> +                ovn_lb_ip_set_clone(lb_group_dps->lb_group->lb_ips);
> +        } else {
> +            for (size_t j = 0; j < lb_group_dps->lb_group->n_lbs; j++) {
> +                build_lrouter_lb_ips(lr_lbnat_rec->lb_ips,
> +                                     lb_group_dps->lb_group->lbs[j]);
> +            }
> +        }
> +
> +        for (size_t j = 0; j < lb_group_dps->lb_group->n_lbs; j++) {
> +            build_lrouter_lb_reachable_ips(lr_lbnat_rec,
> +
lb_group_dps->lb_group->lbs[j]);
> +        }
> +    }
> +
> +    if (!lr_lbnat_rec->lb_ips) {
> +        lr_lbnat_rec->lb_ips = ovn_lb_ip_set_create();
> +    }
> +
> +    for (size_t i = 0; i < nbr->n_load_balancer; i++) {
> +        const struct uuid *lb_uuid =
> +            &nbr->load_balancer[i]->header_.uuid;
> +        lb_dps = ovn_lb_datapaths_find(lb_datapaths_map, lb_uuid);
> +        ovs_assert(lb_dps);
> +        build_lrouter_lb_ips(lr_lbnat_rec->lb_ips, lb_dps->lb);
> +        build_lrouter_lb_reachable_ips(lr_lbnat_rec, lb_dps->lb);
> +    }
> +
> +    sset_init(&lr_lbnat_rec->vip_nats);
> +
> +    if (!nbr->n_nat) {
> +        lr_lb_nat_data_build_vip_nats(lr_lbnat_rec);
> +    }
> +}
> +
> +static struct lr_lb_nat_data_input
> +lr_lb_nat_data_get_input_data(struct engine_node *node)
> +{
> +    struct northd_data *northd_data = engine_get_input_data("northd",
node);
> +    struct ed_type_lr_nat_data *lr_nat_data =
> +        engine_get_input_data("lr_nat", node);
> +
> +    return (struct lr_lb_nat_data_input) {
> +        .lr_datapaths = &northd_data->lr_datapaths,
> +        .lb_datapaths_map = &northd_data->lb_datapaths_map,
> +        .lbgrp_datapaths_map = &northd_data->lb_group_datapaths_map,
> +        .lr_nats = &lr_nat_data->lr_nats,
> +    };
> +}
> +
> +static void
> +build_lrouter_lb_reachable_ips(struct lr_lb_nat_data_record
*lr_lbnat_rec,
> +                               const struct ovn_northd_lb *lb)
> +{
> +    add_neigh_ips_to_lrouter(lr_lbnat_rec, lb->neigh_mode, &lb->ips_v4,
> +                             &lb->ips_v6);
> +}
> +
> +static void
> +add_neigh_ips_to_lrouter(struct lr_lb_nat_data_record *lr_lbnat_rec,
> +                         enum lb_neighbor_responder_mode neigh_mode,
> +                         const struct sset *lb_ips_v4,
> +                         const struct sset *lb_ips_v6)
> +{
> +    /* If configured to not reply to any neighbor requests for all VIPs
> +     * return early.
> +     */
> +    if (neigh_mode == LB_NEIGH_RESPOND_NONE) {
> +        return;
> +    }
> +
> +    const char *ip_address;
> +
> +    /* If configured to reply to neighbor requests for all VIPs force
them
> +     * all to be considered "reachable".
> +     */
> +    if (neigh_mode == LB_NEIGH_RESPOND_ALL) {
> +        SSET_FOR_EACH (ip_address, lb_ips_v4) {
> +            sset_add(&lr_lbnat_rec->lb_ips->ips_v4_reachable,
ip_address);
> +        }
> +        SSET_FOR_EACH (ip_address, lb_ips_v6) {
> +            sset_add(&lr_lbnat_rec->lb_ips->ips_v6_reachable,
ip_address);
> +        }
> +
> +        return;
> +    }
> +
> +    /* Otherwise, a VIP is reachable if there's at least one router
> +     * subnet that includes it.
> +     */
> +    ovs_assert(neigh_mode == LB_NEIGH_RESPOND_REACHABLE);
> +
> +    SSET_FOR_EACH (ip_address, lb_ips_v4) {
> +        struct ovn_port *op;
> +        ovs_be32 vip_ip4;
> +        if (ip_parse(ip_address, &vip_ip4)) {
> +            HMAP_FOR_EACH (op, dp_node, &lr_lbnat_rec->od->ports) {
> +                if (lrouter_port_ipv4_reachable(op, vip_ip4)) {
> +                    sset_add(&lr_lbnat_rec->lb_ips->ips_v4_reachable,
> +                             ip_address);
> +                    break;
> +                }
> +            }
> +        }
> +    }
> +
> +    SSET_FOR_EACH (ip_address, lb_ips_v6) {
> +        struct ovn_port *op;
> +        struct in6_addr vip;
> +        if (ipv6_parse(ip_address, &vip)) {
> +            HMAP_FOR_EACH (op, dp_node, &lr_lbnat_rec->od->ports) {
> +                if (lrouter_port_ipv6_reachable(op, &vip)) {
> +                    sset_add(&lr_lbnat_rec->lb_ips->ips_v6_reachable,
> +                             ip_address);
> +                    break;
> +                }
> +            }
> +        }
> +    }
> +}
> +
> +static void
> +remove_lrouter_lb_reachable_ips(struct lr_lb_nat_data_record
*lr_lbnat_rec,
> +                                enum lb_neighbor_responder_mode
neigh_mode,
> +                                const struct sset *lb_ips_v4,
> +                                const struct sset *lb_ips_v6)
> +{
> +    if (neigh_mode == LB_NEIGH_RESPOND_NONE) {
> +        return;
> +    }
> +
> +    const char *ip_address;
> +    SSET_FOR_EACH (ip_address, lb_ips_v4) {
> +        sset_find_and_delete(&lr_lbnat_rec->lb_ips->ips_v4_reachable,
> +                             ip_address);
> +    }
> +    SSET_FOR_EACH (ip_address, lb_ips_v6) {
> +        sset_find_and_delete(&lr_lbnat_rec->lb_ips->ips_v6_reachable,
> +                             ip_address);
> +    }
> +}
> +
> +static void
> +lr_lb_nat_data_build_vip_nats(struct lr_lb_nat_data_record *lr_lbnat_rec)
> +{
> +    sset_clear(&lr_lbnat_rec->vip_nats);
> +    const char *external_ip;
> +    SSET_FOR_EACH (external_ip, &lr_lbnat_rec->lrnat_rec->external_ips) {
> +        bool is_vip_nat = false;
> +        if (addr_is_ipv6(external_ip)) {
> +            is_vip_nat = sset_contains(&lr_lbnat_rec->lb_ips->ips_v6,
> +                                       external_ip);
> +        } else {
> +            is_vip_nat = sset_contains(&lr_lbnat_rec->lb_ips->ips_v4,
> +                                       external_ip);
> +        }
> +
> +        if (is_vip_nat) {
> +            sset_add(&lr_lbnat_rec->vip_nats, external_ip);
> +        }
> +    }
> +}
> diff --git a/northd/en-lr-lb-nat-data.h b/northd/en-lr-lb-nat-data.h
> new file mode 100644
> index 0000000000..9029aee339
> --- /dev/null
> +++ b/northd/en-lr-lb-nat-data.h
> @@ -0,0 +1,93 @@
> +/*
> + * Copyright (c) 2023, Red Hat, Inc.
> + *
> + * Licensed under the Apache License, Version 2.0 (the "License");
> + * you may not use this file except in compliance with the License.
> + * You may obtain a copy of the License at:
> + *
> + *     http://www.apache.org/licenses/LICENSE-2.0
> + *
> + * Unless required by applicable law or agreed to in writing, software
> + * distributed under the License is distributed on an "AS IS" BASIS,
> + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
implied.
> + * See the License for the specific language governing permissions and
> + * limitations under the License.
> + */
> +#ifndef EN_LR_LB_NAT_DATA_H
> +#define EN_LR_LB_NAT_DATA_H 1
> +
> +#include <stdint.h>
> +
> +/* OVS includes. */
> +#include "lib/hmapx.h"
> +#include "openvswitch/hmap.h"
> +#include "sset.h"
> +
> +/* OVN includes. */
> +#include "lib/inc-proc-eng.h"
> +#include "lib/lb.h"
> +#include "lib/ovn-nb-idl.h"
> +#include "lib/ovn-sb-idl.h"
> +#include "lib/ovn-util.h"
> +
> +struct ovn_datapath;
> +struct lr_nat_record;
> +
> +struct lr_lb_nat_data_record {
> +    struct hmap_node key_node; /* Index on 'nbr->header_.uuid'. */
> +
> +    const struct ovn_datapath *od;
> +    const struct lr_nat_record *lrnat_rec;
> +
> +    /* Load Balancer vIPs relevant for this datapath. */
> +    struct ovn_lb_ip_set *lb_ips;
> +
> +    /* sset of vips which are also part of lr nats. */
> +    struct sset vip_nats;
> +};
> +
> +struct lr_lb_nat_data_table {
> +    struct hmap entries;
> +
> +    /* The array index of each element in 'entries'. */
> +    struct lr_lb_nat_data_record **array;
> +};
> +
> +#define LR_LB_NAT_DATA_TABLE_FOR_EACH(LR_LB_NAT_REC, TABLE) \
> +    HMAP_FOR_EACH (LR_LB_NAT_REC, key_node, &(TABLE)->entries)
> +
> +struct lr_lb_nat_data_tracked_data {
> +    /* Created or updated logical router with LB data. */
> +    struct hmapx crupdated; /* Stores 'struct lr_lb_nat_data_record'. */
> +
> +    /* Deleted logical router with LB data. */
> +    struct hmapx deleted; /* Stores 'struct lr_lb_nat_data_record'. */
> +};
> +
> +struct ed_type_lr_lb_nat_data {
> +    struct lr_lb_nat_data_table lr_lbnats;
> +
> +    bool tracked;
> +    struct lr_lb_nat_data_tracked_data tracked_data;
> +};
> +
> +struct lr_lb_nat_data_input {
> +    const struct ovn_datapaths *lr_datapaths;
> +    const struct hmap *lb_datapaths_map;
> +    const struct hmap *lbgrp_datapaths_map;
> +    const struct lr_nat_table *lr_nats;
> +};
> +
> +void *en_lr_lb_nat_data_init(struct engine_node *, struct engine_arg *);
> +void en_lr_lb_nat_data_cleanup(void *data);
> +void en_lr_lb_nat_data_clear_tracked_data(void *data);
> +void en_lr_lb_nat_data_run(struct engine_node *, void *data);
> +
> +bool lr_lb_nat_data_northd_handler(struct engine_node *, void *data);
> +bool lr_lb_nat_data_lr_nat_handler(struct engine_node *, void *data);
> +bool lr_lb_nat_data_lb_data_handler(struct engine_node *, void *data);
> +
> +const struct lr_lb_nat_data_record *lr_lb_nat_data_table_find_by_index(
> +    const struct lr_lb_nat_data_table *, size_t od_index);
> +
> +#endif /* EN_LR_LB_NAT_DATA_H */
> \ No newline at end of file
> diff --git a/northd/en-lr-nat.h b/northd/en-lr-nat.h
> index 01a16a21aa..2e3f285d12 100644
> --- a/northd/en-lr-nat.h
> +++ b/northd/en-lr-nat.h
> @@ -89,6 +89,9 @@ struct lr_nat_table {
>  const struct lr_nat_record * lr_nat_table_find_by_index(
>      const struct lr_nat_table *, size_t od_index);
>
> +#define LR_NAT_TABLE_FOR_EACH(LR_NAT_REC, TABLE) \
> +    HMAP_FOR_EACH (LR_NAT_REC, key_node, &(TABLE)->entries)
> +
>  /* Incremental processing implementation. */
>  struct lr_nat_input {
>      /* Northbound table references. */
> diff --git a/northd/en-sync-sb.c b/northd/en-sync-sb.c
> index 10ade620e7..7c22949f74 100644
> --- a/northd/en-sync-sb.c
> +++ b/northd/en-sync-sb.c
> @@ -22,6 +22,7 @@
>  #include "openvswitch/util.h"
>
>  #include "en-lr-nat.h"
> +#include "en-lr-lb-nat-data.h"
>  #include "en-sync-sb.h"
>  #include "lib/inc-proc-eng.h"
>  #include "lib/lb.h"
> @@ -41,7 +42,7 @@ static void sync_addr_sets(struct ovsdb_idl_txn
*ovnsb_txn,
>                             const struct nbrec_address_set_table *,
>                             const struct nbrec_port_group_table *,
>                             const struct sbrec_address_set_table *,
> -                           const struct ovn_datapaths *lr_datapaths);
> +                           const struct lr_lb_nat_data_table *);
>  static const struct sbrec_address_set *sb_address_set_lookup_by_name(
>      struct ovsdb_idl_index *, const char *name);
>  static void update_sb_addr_set(struct sorted_array *,
> @@ -87,11 +88,11 @@ en_sync_to_sb_addr_set_run(struct engine_node *node,
void *data OVS_UNUSED)
>          EN_OVSDB_GET(engine_get_input("SB_address_set", node));
>
>      const struct engine_context *eng_ctx = engine_get_context();
> -    struct northd_data *northd_data = engine_get_input_data("northd",
node);
> -
> +    const struct ed_type_lr_lb_nat_data *lr_lb_nat_data =
> +        engine_get_input_data("lr_lb_nat_data", node);
>      sync_addr_sets(eng_ctx->ovnsb_idl_txn, nb_address_set_table,
>                     nb_port_group_table, sb_address_set_table,
> -                   &northd_data->lr_datapaths);
> +                   &lr_lb_nat_data->lr_lbnats);
>
>      engine_set_node_state(node, EN_UPDATED);
>  }
> @@ -288,10 +289,12 @@ en_sync_to_sb_pb_run(struct engine_node *node, void
*data OVS_UNUSED)
>  {
>      const struct engine_context *eng_ctx = engine_get_context();
>      struct northd_data *northd_data = engine_get_input_data("northd",
node);
> -    struct ed_type_lr_nat_data *lr_nat_data =
> -        engine_get_input_data("lr_nat", node);
> +    struct ed_type_lr_lb_nat_data *lr_lb_nat_data =
> +        engine_get_input_data("lr_lb_nat_data", node);
> +
>      sync_pbs(eng_ctx->ovnsb_idl_txn, &northd_data->ls_ports,
> -             &northd_data->lr_ports, &lr_nat_data->lr_nats);
> +             &northd_data->lr_ports,
> +             &lr_lb_nat_data->lr_lbnats);
>      engine_set_node_state(node, EN_UPDATED);
>  }
>
> @@ -316,11 +319,12 @@ sync_to_sb_pb_northd_handler(struct engine_node
*node, void *data OVS_UNUSED)
>          return false;
>      }
>
> -    struct ed_type_lr_nat_data *lr_nat_data =
> -        engine_get_input_data("lr_nat", node);
> +    struct ed_type_lr_lb_nat_data *lr_lb_nat_data =
> +        engine_get_input_data("lr_lb_nat_data", node);
>
>      if (!sync_pbs_for_northd_changed_ovn_ports(
> -            &nd->trk_northd_changes.trk_ovn_ports,
&lr_nat_data->lr_nats)) {
> +            &nd->trk_northd_changes.trk_ovn_ports,
> +            &lr_lb_nat_data->lr_lbnats)) {
>          return false;
>      }
>
> @@ -366,7 +370,7 @@ sync_addr_sets(struct ovsdb_idl_txn *ovnsb_txn,
>                 const struct nbrec_address_set_table
*nb_address_set_table,
>                 const struct nbrec_port_group_table *nb_port_group_table,
>                 const struct sbrec_address_set_table
*sb_address_set_table,
> -               const struct ovn_datapaths *lr_datapaths)
> +               const struct lr_lb_nat_data_table *lr_lbnats)
>  {
>      struct shash sb_address_sets = SHASH_INITIALIZER(&sb_address_sets);
>
> @@ -410,16 +414,14 @@ sync_addr_sets(struct ovsdb_idl_txn *ovnsb_txn,
>      }
>
>      /* Sync router load balancer VIP generated address sets. */
> -    struct ovn_datapath *od;
> -    HMAP_FOR_EACH (od, key_node, &lr_datapaths->datapaths) {
> -        ovs_assert(od->nbr);
> -
> -        if (sset_count(&od->lb_ips->ips_v4_reachable)) {
> -            char *ipv4_addrs_name =
lr_lb_address_set_name(od->tunnel_key,
> -                                                           AF_INET);
> +    const struct lr_lb_nat_data_record *lrlb_rec;
> +    LR_LB_NAT_DATA_TABLE_FOR_EACH (lrlb_rec, lr_lbnats) {
> +        if (sset_count(&lrlb_rec->lb_ips->ips_v4_reachable)) {
> +            char *ipv4_addrs_name =
> +                lr_lb_address_set_name(lrlb_rec->od->tunnel_key,
AF_INET);
>
>              struct sorted_array ipv4_addrs_sorted =
> -
 sorted_array_from_sset(&od->lb_ips->ips_v4_reachable);
> +
 sorted_array_from_sset(&lrlb_rec->lb_ips->ips_v4_reachable);
>
>              sync_addr_set(ovnsb_txn, ipv4_addrs_name,
>                            &ipv4_addrs_sorted, &sb_address_sets);
> @@ -427,11 +429,11 @@ sync_addr_sets(struct ovsdb_idl_txn *ovnsb_txn,
>              free(ipv4_addrs_name);
>          }
>
> -        if (sset_count(&od->lb_ips->ips_v6_reachable)) {
> -            char *ipv6_addrs_name =
lr_lb_address_set_name(od->tunnel_key,
> -                                                           AF_INET6);
> -            struct sorted_array ipv6_addrs_sorted =
> -
 sorted_array_from_sset(&od->lb_ips->ips_v6_reachable);
> +        if (sset_count(&lrlb_rec->lb_ips->ips_v6_reachable)) {
> +            char *ipv6_addrs_name =
> +                lr_lb_address_set_name(lrlb_rec->od->tunnel_key,
AF_INET6);
> +            struct sorted_array ipv6_addrs_sorted =
sorted_array_from_sset(
> +                &lrlb_rec->lb_ips->ips_v6_reachable);
>
>              sync_addr_set(ovnsb_txn, ipv6_addrs_name,
>                            &ipv6_addrs_sorted, &sb_address_sets);
> diff --git a/northd/inc-proc-northd.c b/northd/inc-proc-northd.c
> index 2bd66b8808..369a151fa3 100644
> --- a/northd/inc-proc-northd.c
> +++ b/northd/inc-proc-northd.c
> @@ -31,6 +31,7 @@
>  #include "openvswitch/vlog.h"
>  #include "inc-proc-northd.h"
>  #include "en-lb-data.h"
> +#include "en-lr-lb-nat-data.h"
>  #include "en-lr-nat.h"
>  #include "en-northd.h"
>  #include "en-lflow.h"
> @@ -148,6 +149,7 @@ static ENGINE_NODE(sync_to_sb_lb, "sync_to_sb_lb");
>  static ENGINE_NODE(sync_to_sb_pb, "sync_to_sb_pb");
>  static ENGINE_NODE_WITH_CLEAR_TRACK_DATA(lb_data, "lb_data");
>  static ENGINE_NODE_WITH_CLEAR_TRACK_DATA(lr_nat, "lr_nat");
> +static ENGINE_NODE_WITH_CLEAR_TRACK_DATA(lr_lb_nat_data,
"lr_lb_nat_data");
>
>  void inc_proc_northd_init(struct ovsdb_idl_loop *nb,
>                            struct ovsdb_idl_loop *sb)
> @@ -196,6 +198,13 @@ void inc_proc_northd_init(struct ovsdb_idl_loop *nb,
>      engine_add_input(&en_lr_nat, &en_nb_logical_router,
>                       lr_nat_logical_router_handler);
>
> +    engine_add_input(&en_lr_lb_nat_data, &en_northd,
> +                     lr_lb_nat_data_northd_handler);
> +    engine_add_input(&en_lr_lb_nat_data, &en_lr_nat,
> +                     lr_lb_nat_data_lr_nat_handler);
> +    engine_add_input(&en_lr_lb_nat_data, &en_lb_data,
> +                     lr_lb_nat_data_lb_data_handler);
> +
>      engine_add_input(&en_mac_binding_aging, &en_nb_nb_global, NULL);
>      engine_add_input(&en_mac_binding_aging, &en_sb_mac_binding, NULL);
>      engine_add_input(&en_mac_binding_aging, &en_northd, NULL);
> @@ -220,12 +229,14 @@ void inc_proc_northd_init(struct ovsdb_idl_loop *nb,
>      engine_add_input(&en_lflow, &en_northd, lflow_northd_handler);
>      engine_add_input(&en_lflow, &en_port_group,
lflow_port_group_handler);
>      engine_add_input(&en_lflow, &en_lr_nat, NULL);
> +    engine_add_input(&en_lflow, &en_lr_lb_nat_data, NULL);
>
>      engine_add_input(&en_sync_to_sb_addr_set, &en_nb_address_set,
>                       sync_to_sb_addr_set_nb_address_set_handler);
>      engine_add_input(&en_sync_to_sb_addr_set, &en_nb_port_group,
>                       sync_to_sb_addr_set_nb_port_group_handler);
>      engine_add_input(&en_sync_to_sb_addr_set, &en_northd, NULL);
> +    engine_add_input(&en_sync_to_sb_addr_set, &en_lr_lb_nat_data, NULL);
>      engine_add_input(&en_sync_to_sb_addr_set, &en_sb_address_set, NULL);
>
>      engine_add_input(&en_port_group, &en_nb_port_group,
> @@ -243,7 +254,7 @@ void inc_proc_northd_init(struct ovsdb_idl_loop *nb,
>
>      engine_add_input(&en_sync_to_sb_pb, &en_northd,
>                       sync_to_sb_pb_northd_handler);
> -    engine_add_input(&en_sync_to_sb_pb, &en_lr_nat, NULL);
> +    engine_add_input(&en_sync_to_sb_pb, &en_lr_lb_nat_data, NULL);
>
>      /* en_sync_to_sb engine node syncs the SB database tables from
>       * the NB database tables.
> diff --git a/northd/northd.c b/northd/northd.c
> index 44c9c3d729..24df14c0de 100644
> --- a/northd/northd.c
> +++ b/northd/northd.c
> @@ -44,6 +44,7 @@
>  #include "northd.h"
>  #include "en-lb-data.h"
>  #include "en-lr-nat.h"
> +#include "en-lr-lb-nat-data.h"
>  #include "lib/ovn-parallel-hmap.h"
>  #include "ovn/actions.h"
>  #include "ovn/features.h"
> @@ -617,13 +618,6 @@ init_lb_for_datapath(struct ovn_datapath *od)
>      }
>  }
>
> -static void
> -destroy_lb_for_datapath(struct ovn_datapath *od)
> -{
> -    ovn_lb_ip_set_destroy(od->lb_ips);
> -    od->lb_ips = NULL;
> -}
> -
>  /* A group of logical router datapaths which are connected - either
>   * directly or indirectly.
>   * Each logical router can belong to only one group. */
> @@ -676,7 +670,6 @@ ovn_datapath_destroy(struct hmap *datapaths, struct
ovn_datapath *od)
>          destroy_ipam_info(&od->ipam_info);
>          free(od->router_ports);
>          free(od->ls_peers);
> -        destroy_lb_for_datapath(od);
>          free(od->localnet_ports);
>          free(od->l3dgw_ports);
>          destroy_mcast_info_for_datapath(od);
> @@ -1311,121 +1304,6 @@ struct lflow_ref_node {
>      struct ovn_lflow *lflow;
>  };
>
> -/* A logical switch port or logical router port.
> - *
> - * In steady state, an ovn_port points to a northbound
Logical_Switch_Port
> - * record (via 'nbsp') *or* a Logical_Router_Port record (via 'nbrp'),
and to a
> - * southbound Port_Binding record (via 'sb').  As the state of the system
> - * changes, join_logical_ports() may determine that there is a new LSP
or LRP
> - * that has no corresponding Port_Binding record (in which case
build_ports())
> - * will create the missing Port_Binding) or that a Port_Binding record
exists
> - * that has no coresponding LSP (in which case build_ports() will delete
the
> - * spurious Port_Binding).  Thus, after build_ports() runs, any given
ovn_port
> - * will have 'sb' nonnull, and 'nbsp' xor 'nbrp' nonnull.
> - *
> - * Ordinarily there is only one ovn_port that points to a given LSP or
LRP (but
> - * distributed gateway ports point a "derived" ovn_port to a duplicate
LRP).
> - */
> -struct ovn_port {
> -    /* Port name aka key.
> -     *
> -     * This is ordinarily the same as nbsp->name or nbrp->name and
> -     * sb->logical_port.  (A distributed gateway port creates a "derived"
> -     * ovn_port with key "cr-%s" % nbrp->name.) */
> -    struct hmap_node key_node;  /* Index on 'key'. */
> -    char *key;                  /* nbsp->name, nbrp->name,
sb->logical_port. */
> -    char *json_key;             /* 'key', quoted for use in JSON. */
> -
> -    const struct sbrec_port_binding *sb;         /* May be NULL. */
> -
> -    uint32_t tunnel_key;
> -
> -    /* Logical switch port data. */
> -    const struct nbrec_logical_switch_port *nbsp; /* May be NULL. */
> -
> -    struct lport_addresses *lsp_addrs;  /* Logical switch port
addresses. */
> -    unsigned int n_lsp_addrs;  /* Total length of lsp_addrs. */
> -    unsigned int n_lsp_non_router_addrs; /* Number of elements from the
> -                                          * beginning of 'lsp_addrs'
extracted
> -                                          * directly from LSP
'addresses'. */
> -
> -    struct lport_addresses *ps_addrs;   /* Port security addresses. */
> -    unsigned int n_ps_addrs;
> -
> -    bool lsp_can_be_inc_processed; /* If it can be incrementally
processed when
> -                                      the port changes. */
> -
> -    /* Logical router port data. */
> -    const struct nbrec_logical_router_port *nbrp; /* May be NULL. */
> -
> -    struct lport_addresses lrp_networks;
> -
> -    struct ovn_port_routable_addresses routables;
> -
> -    /* Logical port multicast data. */
> -    struct mcast_port_info mcast_info;
> -
> -    /* At most one of l3dgw_port and cr_port can be not NULL. */
> -
> -    /* This is set to a distributed gateway port if and only if this
ovn_port
> -     * is "derived" from it. Otherwise this is set to NULL. The derived
> -     * ovn_port represents the instance of distributed gateway port on
the
> -     * gateway chassis.*/
> -    struct ovn_port *l3dgw_port;
> -
> -    /* This is set to the "derived" chassis-redirect port of this port
if and
> -     * only if this port is a distributed gateway port. Otherwise this
is set
> -     * to NULL. */
> -    struct ovn_port *cr_port;
> -
> -    bool has_unknown; /* If the addresses have 'unknown' defined. */
> -
> -    bool has_bfd;
> -
> -    /* The port's peer:
> -     *
> -     *     - A switch port S of type "router" has a router port R as a
peer,
> -     *       and R in turn has S has its peer.
> -     *
> -     *     - Two connected logical router ports have each other as peer.
> -     *
> -     *     - Other kinds of ports have no peer. */
> -    struct ovn_port *peer;
> -
> -    struct ovn_datapath *od;
> -
> -    struct ovs_list list;       /* In list of similar records. */
> -
> -    struct hmap_node dp_node;   /* Node in od->ports. */
> -
> -    struct lport_addresses proxy_arp_addrs;
> -
> -    /* Temporarily used for traversing a list (or hmap) of ports. */
> -    bool visited;
> -
> -    /* List of struct lflow_ref_node that points to the lflows generated
by
> -     * this ovn_port.
> -     *
> -     * This data is initialized and destroyed by the en_northd node, but
> -     * populated and used only by the en_lflow node. Ideally this data
should
> -     * be maintained as part of en_lflow's data (struct lflow_data): a
hash
> -     * index from ovn_port key to lflows.  However, it would be less
efficient
> -     * and more complex:
> -     *
> -     * 1. It would require an extra search (using the index) to find the
> -     * lflows.
> -     *
> -     * 2. Building the index needs to be thread-safe, using either a
global
> -     * lock which is obviously less efficient, or hash-based lock array
which
> -     * is more complex.
> -     *
> -     * Adding the list here is more straightforward. The drawback is
that we
> -     * need to keep in mind that this data belongs to en_lflow node, so
never
> -     * access it from any other nodes.
> -     */
> -    struct ovs_list lflows;
> -};
> -
>  static bool lsp_can_be_inc_processed(const struct
nbrec_logical_switch_port *);
>
>  static bool
> @@ -1450,16 +1328,21 @@ destroy_routable_addresses(struct
ovn_port_routable_addresses *ra)
>  }
>
>  static char **get_nat_addresses(const struct ovn_port *op, size_t *n,
> -                                bool routable_only, bool include_lb_ips);
> +                                bool routable_only, bool include_lb_ips,
> +                                const struct lr_lb_nat_data_record *);
>
> -static void
> -assign_routable_addresses(struct ovn_port *op)
> +static struct ovn_port_routable_addresses
> +get_op_routable_addresses(struct ovn_port *op,
> +                          const struct lr_lb_nat_data_record
*lr_lbnat_rec)
>  {
>      size_t n;
> -    char **nats = get_nat_addresses(op, &n, true, true);
> +    char **nats = get_nat_addresses(op, &n, true, true, lr_lbnat_rec);
>
>      if (!nats) {
> -        return;
> +        return (struct ovn_port_routable_addresses) {
> +            .laddrs = NULL,
> +            .n_addrs = 0,
> +        };
>      }
>
>      struct lport_addresses *laddrs = xcalloc(n, sizeof(*laddrs));
> @@ -1475,9 +1358,15 @@ assign_routable_addresses(struct ovn_port *op)
>      }
>      free(nats);
>
> -    /* Everything seems to have worked out */
> -    op->routables.laddrs = laddrs;
> -    op->routables.n_addrs = n_addrs;
> +    if (!n_addrs) {
> +        free(laddrs);
> +        laddrs = NULL;
> +    }
> +
> +    return (struct ovn_port_routable_addresses) {
> +        .laddrs = laddrs,
> +        .n_addrs = n_addrs,
> +    };
>  }
>
>
> @@ -1537,8 +1426,6 @@ ovn_port_destroy_orphan(struct ovn_port *port)
>      }
>      free(port->ps_addrs);
>
> -    destroy_routable_addresses(&port->routables);
> -
>      destroy_lport_addresses(&port->lrp_networks);
>      destroy_lport_addresses(&port->proxy_arp_addrs);
>      free(port->json_key);
> @@ -2580,9 +2467,7 @@ join_logical_ports(const struct
sbrec_port_binding_table *sbrec_pb_table,
>                                                   sizeof
*od->l3dgw_ports);
>                  }
>                  od->l3dgw_ports[od->n_l3dgw_ports++] = op;
> -
> -                assign_routable_addresses(op);
> -            }
> +           }
>          }
>      }
>
> @@ -2679,7 +2564,8 @@ join_logical_ports(const struct
sbrec_port_binding_table *sbrec_pb_table,
>   * and must free the returned array when it is no longer needed. */
>  static char **
>  get_nat_addresses(const struct ovn_port *op, size_t *n, bool
routable_only,
> -                  bool include_lb_ips)
> +                  bool include_lb_ips,
> +                  const struct lr_lb_nat_data_record *lr_lbnat_rec)
>  {
>      size_t n_nats = 0;
>      struct eth_addr mac;
> @@ -2764,23 +2650,25 @@ get_nat_addresses(const struct ovn_port *op,
size_t *n, bool routable_only,
>          }
>      }
>
> -    if (include_lb_ips) {
> +    if (include_lb_ips && lr_lbnat_rec) {
>          const char *ip_address;
>          if (routable_only) {
> -            SSET_FOR_EACH (ip_address, &op->od->lb_ips->ips_v4_routable)
{
> +            SSET_FOR_EACH (ip_address,
> +                           &lr_lbnat_rec->lb_ips->ips_v4_routable) {
>                  ds_put_format(&c_addresses, " %s", ip_address);
>                  central_ip_address = true;
>              }
> -            SSET_FOR_EACH (ip_address, &op->od->lb_ips->ips_v6_routable)
{
> +            SSET_FOR_EACH (ip_address,
> +                           &lr_lbnat_rec->lb_ips->ips_v6_routable) {
>                  ds_put_format(&c_addresses, " %s", ip_address);
>                  central_ip_address = true;
>              }
>          } else {
> -            SSET_FOR_EACH (ip_address, &op->od->lb_ips->ips_v4) {
> +            SSET_FOR_EACH (ip_address, &lr_lbnat_rec->lb_ips->ips_v4) {
>                  ds_put_format(&c_addresses, " %s", ip_address);
>                  central_ip_address = true;
>              }
> -            SSET_FOR_EACH (ip_address, &op->od->lb_ips->ips_v6) {
> +            SSET_FOR_EACH (ip_address, &lr_lbnat_rec->lb_ips->ips_v6) {
>                  ds_put_format(&c_addresses, " %s", ip_address);
>                  central_ip_address = true;
>              }
> @@ -3851,21 +3739,8 @@ build_lb_datapaths(const struct hmap *lbs, const
struct hmap *lb_groups,
>      HMAP_FOR_EACH (od, key_node, &lr_datapaths->datapaths) {
>          ovs_assert(od->nbr);
>
> -        /* Checking load balancer groups first, starting from the
largest one,
> -         * to more efficiently copy IP sets. */
> -        size_t largest_group = 0;
> -
> -        for (size_t i = 1; i < od->nbr->n_load_balancer_group; i++) {
> -            if (od->nbr->load_balancer_group[i]->n_load_balancer >
> -
 od->nbr->load_balancer_group[largest_group]->n_load_balancer) {
> -                largest_group = i;
> -            }
> -        }
> -
>          for (size_t i = 0; i < od->nbr->n_load_balancer_group; i++) {
> -            size_t idx = (i + largest_group) %
od->nbr->n_load_balancer_group;
> -
> -            nbrec_lb_group = od->nbr->load_balancer_group[idx];
> +            nbrec_lb_group = od->nbr->load_balancer_group[i];
>              const struct uuid *lb_group_uuid =
&nbrec_lb_group->header_.uuid;
>
>              lb_group_dps =
> @@ -3873,20 +3748,6 @@ build_lb_datapaths(const struct hmap *lbs, const
struct hmap *lb_groups,
>                                              lb_group_uuid);
>              ovs_assert(lb_group_dps);
>              ovn_lb_group_datapaths_add_lr(lb_group_dps, od);
> -
> -            if (!od->lb_ips) {
> -                od->lb_ips =
> -                    ovn_lb_ip_set_clone(lb_group_dps->lb_group->lb_ips);
> -            } else {
> -                for (size_t j = 0; j < lb_group_dps->lb_group->n_lbs;
j++) {
> -                    build_lrouter_lb_ips(od->lb_ips,
> -                                         lb_group_dps->lb_group->lbs[j]);
> -                }
> -            }
> -        }
> -
> -        if (!od->lb_ips) {
> -            od->lb_ips = ovn_lb_ip_set_create();
>          }
>
>          for (size_t i = 0; i < od->nbr->n_load_balancer; i++) {
> @@ -3895,7 +3756,6 @@ build_lb_datapaths(const struct hmap *lbs, const
struct hmap *lb_groups,
>              lb_dps = ovn_lb_datapaths_find(lb_datapaths_map, lb_uuid);
>              ovs_assert(lb_dps);
>              ovn_lb_datapaths_add_lr(lb_dps, 1, &od);
> -            build_lrouter_lb_ips(od->lb_ips, lb_dps->lb);
>          }
>      }
>
> @@ -3949,102 +3809,6 @@ build_lb_svcs(
>      }
>  }
>
> -static bool lrouter_port_ipv4_reachable(const struct ovn_port *op,
> -                                        ovs_be32 addr);
> -static bool lrouter_port_ipv6_reachable(const struct ovn_port *op,
> -                                        const struct in6_addr *addr);
> -
> -static void
> -add_neigh_ips_to_lrouter(struct ovn_datapath *od,
> -                         enum lb_neighbor_responder_mode neigh_mode,
> -                         const struct sset *lb_ips_v4,
> -                         const struct sset *lb_ips_v6)
> -{
> -    /* If configured to not reply to any neighbor requests for all VIPs
> -     * return early.
> -     */
> -    if (neigh_mode == LB_NEIGH_RESPOND_NONE) {
> -        return;
> -    }
> -
> -    const char *ip_address;
> -
> -    /* If configured to reply to neighbor requests for all VIPs force
them
> -     * all to be considered "reachable".
> -     */
> -    if (neigh_mode == LB_NEIGH_RESPOND_ALL) {
> -        SSET_FOR_EACH (ip_address, lb_ips_v4) {
> -            sset_add(&od->lb_ips->ips_v4_reachable, ip_address);
> -        }
> -        SSET_FOR_EACH (ip_address, lb_ips_v6) {
> -            sset_add(&od->lb_ips->ips_v6_reachable, ip_address);
> -        }
> -
> -        return;
> -    }
> -
> -    /* Otherwise, a VIP is reachable if there's at least one router
> -     * subnet that includes it.
> -     */
> -    ovs_assert(neigh_mode == LB_NEIGH_RESPOND_REACHABLE);
> -
> -    SSET_FOR_EACH (ip_address, lb_ips_v4) {
> -        struct ovn_port *op;
> -        ovs_be32 vip_ip4;
> -        if (ip_parse(ip_address, &vip_ip4)) {
> -            HMAP_FOR_EACH (op, dp_node, &od->ports) {
> -                if (lrouter_port_ipv4_reachable(op, vip_ip4)) {
> -                    sset_add(&od->lb_ips->ips_v4_reachable,
> -                             ip_address);
> -                    break;
> -                }
> -            }
> -        }
> -    }
> -
> -    SSET_FOR_EACH (ip_address, lb_ips_v6) {
> -        struct ovn_port *op;
> -        struct in6_addr vip;
> -        if (ipv6_parse(ip_address, &vip)) {
> -            HMAP_FOR_EACH (op, dp_node, &od->ports) {
> -                if (lrouter_port_ipv6_reachable(op, &vip)) {
> -                    sset_add(&od->lb_ips->ips_v6_reachable,
> -                             ip_address);
> -                    break;
> -                }
> -            }
> -        }
> -    }
> -}
> -
> -static void
> -remove_lrouter_lb_reachable_ips(struct ovn_datapath *od,
> -                                enum lb_neighbor_responder_mode
neigh_mode,
> -                                const struct sset *lb_ips_v4,
> -                                const struct sset *lb_ips_v6)
> -{
> -    if (neigh_mode == LB_NEIGH_RESPOND_NONE) {
> -        return;
> -    }
> -
> -    const char *ip_address;
> -    SSET_FOR_EACH (ip_address, lb_ips_v4) {
> -        sset_find_and_delete(&od->lb_ips->ips_v4_reachable, ip_address);
> -    }
> -    SSET_FOR_EACH (ip_address, lb_ips_v6) {
> -        sset_find_and_delete(&od->lb_ips->ips_v6_reachable, ip_address);
> -    }
> -}
> -
> -static void
> -build_lrouter_lb_reachable_ips(struct ovn_datapath *od,
> -                               const struct ovn_northd_lb *lb)
> -{
> -    add_neigh_ips_to_lrouter(od, lb->neigh_mode, &lb->ips_v4,
> -                             &lb->ips_v6);
> -}
> -
> -
>  static void
>  build_lrouter_lbs_check(const struct ovn_datapaths *lr_datapaths)
>  {
> @@ -4066,43 +3830,6 @@ build_lrouter_lbs_check(const struct ovn_datapaths
*lr_datapaths)
>      }
>  }
>
> -static void
> -build_lrouter_lbs_reachable_ips(struct ovn_datapaths *lr_datapaths,
> -                                struct hmap *lb_dps_map,
> -                                struct hmap *lb_group_dps_map)
> -{
> -    struct ovn_datapath *od;
> -
> -    HMAP_FOR_EACH (od, key_node, &lr_datapaths->datapaths) {
> -        if (!od->nbr) {
> -            continue;
> -        }
> -
> -        for (size_t i = 0; i < od->nbr->n_load_balancer; i++) {
> -            struct ovn_lb_datapaths *lb_dps =
> -                ovn_lb_datapaths_find(lb_dps_map,
> -
 &od->nbr->load_balancer[i]->header_.uuid);
> -            ovs_assert(lb_dps);
> -            build_lrouter_lb_reachable_ips(od, lb_dps->lb);
> -        }
> -
> -        for (size_t i = 0; i < od->nbr->n_load_balancer_group; i++) {
> -            const struct nbrec_load_balancer_group *nbrec_lb_group =
> -                od->nbr->load_balancer_group[i];
> -            struct ovn_lb_group_datapaths *lb_group_dps;
> -
> -            lb_group_dps =
> -                ovn_lb_group_datapaths_find(lb_group_dps_map,
> -
 &nbrec_lb_group->header_.uuid);
> -             ovs_assert(lb_group_dps);
> -            for (size_t j = 0; j < lb_group_dps->lb_group->n_lbs; j++) {
> -                build_lrouter_lb_reachable_ips(od,
> -
lb_group_dps->lb_group->lbs[j]);
> -            }
> -        }
> -    }
> -}
> -
>  static void
>  build_lswitch_lbs_from_lrouter(struct ovn_datapaths *lr_datapaths,
>                                 struct hmap *lb_dps_map,
> @@ -4166,8 +3893,6 @@ build_lb_port_related_data(
>      struct hmap *svc_monitor_map)
>  {
>      build_lrouter_lbs_check(lr_datapaths);
> -    build_lrouter_lbs_reachable_ips(lr_datapaths, lb_dps_map,
> -                                    lb_group_dps_map);
>      build_lb_svcs(ovnsb_txn, sbrec_service_monitor_table, ls_ports,
lb_dps_map,
>                    svc_monitor_lsps, svc_monitor_map);
>      build_lswitch_lbs_from_lrouter(lr_datapaths, lb_dps_map,
lb_group_dps_map);
> @@ -4533,7 +4258,8 @@ check_sb_lb_duplicates(const struct
sbrec_load_balancer_table *table)
>   * Caller should make sure that the OVN SB IDL txn is not NULL.
Presently it
>   * only syncs the nat column of port binding corresponding to the
'op->nbsp' */
>  static void
> -sync_pb_for_lsp(struct ovn_port *op)
> +sync_pb_for_lsp(struct ovn_port *op,
> +                const struct lr_lb_nat_data_table *lr_lbnats)
>  {
>      ovs_assert(op->nbsp);
>
> @@ -4552,10 +4278,17 @@ sync_pb_for_lsp(struct ovn_port *op)
>          if (nat_addresses && !strcmp(nat_addresses, "router")) {
>              if (op->peer && op->peer->od
>                  && (chassis || op->peer->od->n_l3dgw_ports)) {
> -                bool exclude_lb_vips = smap_get_bool(&op->nbsp->options,
> +                bool include_lb_vips = !smap_get_bool(&op->nbsp->options,
>                          "exclude-lb-vips-from-garp", false);
> +
> +                const struct lr_lb_nat_data_record *lr_lbnat_rec = NULL;
> +
> +                if (include_lb_vips) {
> +                    lr_lbnat_rec = lr_lb_nat_data_table_find_by_index(
> +                        lr_lbnats, op->peer->od->index);
> +                }
>                  nats = get_nat_addresses(op->peer, &n_nats, false,
> -                                            !exclude_lb_vips);
> +                                         include_lb_vips, lr_lbnat_rec);
>              }
>          } else if (nat_addresses && (chassis || l3dgw_ports)) {
>              struct lport_addresses laddrs;
> @@ -4662,7 +4395,8 @@ sync_pb_for_lsp(struct ovn_port *op)
>   * Caller should make sure that the OVN SB IDL txn is not NULL.
Presently it
>   * only sets the port binding options column for the router ports */
>  static void
> -sync_pb_for_lrp(struct ovn_port *op, const struct lr_nat_table *lr_nats)
> +sync_pb_for_lrp(struct ovn_port *op,
> +                const struct lr_lb_nat_data_table *lr_lbnats)
>  {
>      ovs_assert(op->nbrp);
>
> @@ -4671,14 +4405,14 @@ sync_pb_for_lrp(struct ovn_port *op, const struct
lr_nat_table *lr_nats)
>
>      const char *chassis_name = smap_get(&op->od->nbr->options,
"chassis");
>      if (is_cr_port(op)) {
> -        const struct lr_nat_record *lrnat_rec =
> -            lr_nat_table_find_by_index(lr_nats, op->od->index);
> -        ovs_assert(lrnat_rec);
> +        const struct lr_lb_nat_data_record *lr_lbnat_rec =
> +            lr_lb_nat_data_table_find_by_index(lr_lbnats, op->od->index);
> +        ovs_assert(lr_lbnat_rec);
>
>          smap_add(&new, "distributed-port", op->nbrp->name);
>
>          bool always_redirect =
> -            !lrnat_rec->has_distributed_nat &&
> +            !lr_lbnat_rec->lrnat_rec->has_distributed_nat &&
>              !l3dgw_port_has_associated_vtep_lports(op->l3dgw_port);
>
>          const char *redirect_type = smap_get(&op->nbrp->options,
> @@ -4729,17 +4463,18 @@ static void ovn_update_ipv6_opt_for_op(struct
ovn_port *op);
>   * the logical switch ports. */
>  void
>  sync_pbs(struct ovsdb_idl_txn *ovnsb_idl_txn, struct hmap *ls_ports,
> -         struct hmap *lr_ports, const struct lr_nat_table *lr_nats)
> +         struct hmap *lr_ports,
> +         const struct lr_lb_nat_data_table *lr_lbnats)
>  {
>      ovs_assert(ovnsb_idl_txn);
>
>      struct ovn_port *op;
>      HMAP_FOR_EACH (op, key_node, ls_ports) {
> -        sync_pb_for_lsp(op);
> +        sync_pb_for_lsp(op, lr_lbnats);
>      }
>
>      HMAP_FOR_EACH (op, key_node, lr_ports) {
> -        sync_pb_for_lrp(op, lr_nats);
> +        sync_pb_for_lrp(op, lr_lbnats);
>      }
>
>      ovn_update_ipv6_options(lr_ports);
> @@ -4748,17 +4483,18 @@ sync_pbs(struct ovsdb_idl_txn *ovnsb_idl_txn,
struct hmap *ls_ports,
>  /* Sync the SB Port bindings for the added and updated logical switch
ports
>   * of the tracked northd engine data. */
>  bool
> -sync_pbs_for_northd_changed_ovn_ports(struct tracked_ovn_ports
*trk_ovn_ports,
> -                                      const struct lr_nat_table *lr_nats)
> +sync_pbs_for_northd_changed_ovn_ports(
> +    struct tracked_ovn_ports *trk_ovn_ports,
> +    const struct lr_lb_nat_data_table *lr_lbnats)
>  {
>      struct hmapx_node *hmapx_node;
>      struct ovn_port *op;
>      HMAPX_FOR_EACH (hmapx_node, &trk_ovn_ports->created) {
>          op = hmapx_node->data;
>          if (op->nbsp) {
> -            sync_pb_for_lsp(op);
> +            sync_pb_for_lsp(op, lr_lbnats);
>          } else {
> -            sync_pb_for_lrp(op, lr_nats);
> +            sync_pb_for_lrp(op, lr_lbnats);
>              ovn_update_ipv6_opt_for_op(op);
>          }
>      }
> @@ -4766,9 +4502,9 @@ sync_pbs_for_northd_changed_ovn_ports(struct
tracked_ovn_ports *trk_ovn_ports,
>      HMAPX_FOR_EACH (hmapx_node, &trk_ovn_ports->updated) {
>          op = hmapx_node->data;
>          if (op->nbsp) {
> -            sync_pb_for_lsp(op);
> +            sync_pb_for_lsp(op, lr_lbnats);
>          } else {
> -            sync_pb_for_lrp(op, lr_nats);
> +            sync_pb_for_lrp(op, lr_lbnats);
>              ovn_update_ipv6_opt_for_op(op);
>          }
>      }
> @@ -5475,20 +5211,24 @@ fail:
>  }
>
>  /* Returns true if the logical router has changes which can be
> - * incrementally handled.
> + * incrementally handled or the changes can be ignored.
>   * Presently supports i-p for the below changes:
>   *    - load balancers and load balancer groups.
> + *
> + * Presently below changes are ignored:
> + *    - router NAT changes - as the engine node lr-nat handles it.
>   */
>  static bool
> -lr_changes_can_be_handled(
> +lr_changes_can_be_handled_or_ignored(
>      const struct nbrec_logical_router *lr)
>  {
>      /* Check if the columns are changed in this row. */
>      enum nbrec_logical_router_column_id col;
>      for (col = 0; col < NBREC_LOGICAL_ROUTER_N_COLUMNS; col++) {
>          if (nbrec_logical_router_is_updated(lr, col)) {
> -            if (col == NBREC_LOGICAL_ROUTER_COL_LOAD_BALANCER ||
> -                col == NBREC_LOGICAL_ROUTER_COL_LOAD_BALANCER_GROUP) {
> +            if (col == NBREC_LOGICAL_ROUTER_COL_LOAD_BALANCER
> +                || col == NBREC_LOGICAL_ROUTER_COL_LOAD_BALANCER_GROUP
> +                || col == NBREC_LOGICAL_ROUTER_COL_NAT) {
>                  continue;
>              }
>              return false;
> @@ -5507,12 +5247,6 @@ lr_changes_can_be_handled(
>                                  OVSDB_IDL_CHANGE_MODIFY) > 0) {
>          return false;
>      }
> -    for (size_t i = 0; i < lr->n_nat; i++) {
> -        if (nbrec_nat_row_get_seqno(lr->nat[i],
> -                                OVSDB_IDL_CHANGE_MODIFY) > 0) {
> -            return false;
> -        }
> -    }
>      for (size_t i = 0; i < lr->n_policies; i++) {
>          if (nbrec_logical_router_policy_row_get_seqno(lr->policies[i],
>                                  OVSDB_IDL_CHANGE_MODIFY) > 0) {
> @@ -5528,14 +5262,15 @@ lr_changes_can_be_handled(
>      return true;
>  }
>
> -/* Return true if changes are handled incrementally, false otherwise.
> +/* Return true if changes are handled incrementally or can be safely
> + * ignored (because those changes are handled by other engine nodes),
> + * false otherwise.
>   * When there are any changes, try to track what's exactly changed and
set
>   * northd_data->change_tracked accordingly: change tracked - true,
otherwise,
>   * false.
>   * Note: Changes to load balancer and load balancer groups associated
with
>   * the logical routers are handled separately in the lb_data change
> - * handlers (northd_handle_lb_data_changes_pre_od and
> - * northd_handle_lb_data_changes_post_od).
> + * handler (northd_handle_lb_data_changes).
>   * */
>  bool
>  northd_handle_lr_changes(const struct northd_input *ni,
> @@ -5550,9 +5285,11 @@ northd_handle_lr_changes(const struct northd_input
*ni,
>              goto fail;
>          }
>
> -        /* Presently only able to handle load balancer and
> -         * load balancer group changes. */
> -        if (!lr_changes_can_be_handled(changed_lr)) {
> +        /* Presently
> +         *   - only able to handle load balancer and load balancer group
> +               changes.
> +         *   - and ignore NAT changes */
> +        if (!lr_changes_can_be_handled_or_ignored(changed_lr)) {
>              goto fail;
>          }
>      }
> @@ -5804,10 +5541,6 @@ northd_handle_lb_data_changes(struct
tracked_lb_data *trk_lb_data,
>              ovs_assert(lb_dps);
>              ovn_lb_datapaths_add_lr(lb_dps, 1, &od);
>
> -            /* Add the lb_ips of lb_dps to the od. */
> -            build_lrouter_lb_ips(od->lb_ips, lb_dps->lb);
> -            build_lrouter_lb_reachable_ips(od, lb_dps->lb);
> -
>              /* Add the lb to the northd tracked data. */
>              hmapx_add(&nd_changes->trk_lbs.crupdated, lb_dps);
>          }
> @@ -5826,10 +5559,6 @@ northd_handle_lb_data_changes(struct
tracked_lb_data *trk_lb_data,
>                  ovs_assert(lb_dps);
>                  ovn_lb_datapaths_add_lr(lb_dps, 1, &od);
>
> -                /* Add the lb_ips of lb_dps to the od. */
> -                build_lrouter_lb_ips(od->lb_ips, lb_dps->lb);
> -                build_lrouter_lb_reachable_ips(od, lb_dps->lb);
> -
>                  /* Add the lb to the northd tracked data. */
>                  hmapx_add(&nd_changes->trk_lbs.crupdated, lb_dps);
>              }
> @@ -5865,22 +5594,6 @@ northd_handle_lb_data_changes(struct
tracked_lb_data *trk_lb_data,
>              /* Re-evaluate 'od->has_lb_vip' */
>              init_lb_for_datapath(od);
>
> -            /* Update the od->lb_ips with the deleted and inserted
> -             * vips (if any). */
> -            remove_ips_from_lb_ip_set(od->lb_ips, lb->routable,
> -                                      &clb->deleted_vips_v4,
> -                                      &clb->deleted_vips_v6);
> -            add_ips_to_lb_ip_set(od->lb_ips, lb->routable,
> -                                 &clb->inserted_vips_v4,
> -                                 &clb->inserted_vips_v6);
> -
> -            remove_lrouter_lb_reachable_ips(od, lb->neigh_mode,
> -                                            &clb->deleted_vips_v4,
> -                                            &clb->deleted_vips_v6);
> -            add_neigh_ips_to_lrouter(od, lb->neigh_mode,
> -                                     &clb->inserted_vips_v4,
> -                                     &clb->inserted_vips_v6);
> -
>              /* Add the lr datapath to the northd tracked data. */
>              hmapx_add(&nd_changes->lr_with_changed_lbs.crupdated, od);
>          }
> @@ -5908,9 +5621,6 @@ northd_handle_lb_data_changes(struct
tracked_lb_data *trk_lb_data,
>                  /* Re-evaluate 'od->has_lb_vip' */
>                  init_lb_for_datapath(od);
>
> -                /* Add the lb_ips of lb_dps to the od. */
> -                build_lrouter_lb_ips(od->lb_ips, lb_dps->lb);
> -
>                  /* Add the lr datapath to the northd tracked data. */
>                  hmapx_add(&nd_changes->lr_with_changed_lbs.crupdated,
od);
>              }
> @@ -9202,7 +8912,7 @@ arp_nd_ns_match(const char *ips, int addr_family,
struct ds *match)
>  /* Returns 'true' if the IPv4 'addr' is on the same subnet with one of
the
>   * IPs configured on the router port.
>   */
> -static bool
> +bool
>  lrouter_port_ipv4_reachable(const struct ovn_port *op, ovs_be32 addr)
>  {
>      for (size_t i = 0; i < op->lrp_networks.n_ipv4_addrs; i++) {
> @@ -9218,7 +8928,7 @@ lrouter_port_ipv4_reachable(const struct ovn_port
*op, ovs_be32 addr)
>  /* Returns 'true' if the IPv6 'addr' is on the same subnet with one of
the
>   * IPs configured on the router port.
>   */
> -static bool
> +bool
>  lrouter_port_ipv6_reachable(const struct ovn_port *op,
>                              const struct in6_addr *addr)
>  {
> @@ -9284,6 +8994,7 @@ build_lswitch_rport_arp_req_flows(struct ovn_port
*op,
>                                    struct ovn_datapath *sw_od,
>                                    struct ovn_port *sw_op,
>                                    const struct lr_nat_table *lr_nats,
> +                                  const struct lr_lb_nat_data_table
*lr_lbnats,
>                                    struct hmap *lflows,
>                                    const struct ovsdb_idl_row *stage_hint)
>  {
> @@ -9299,32 +9010,38 @@ build_lswitch_rport_arp_req_flows(struct ovn_port
*op,
>       * router port.
>       * Priority: 80.
>       */
> -
> -    const char *ip_addr;
> -    SSET_FOR_EACH (ip_addr, &op->od->lb_ips->ips_v4_reachable) {
> -        ovs_be32 ipv4_addr;
> -
> -        /* Check if the ovn port has a network configured on which we
could
> -         * expect ARP requests for the LB VIP.
> -         */
> -        if (ip_parse(ip_addr, &ipv4_addr) &&
> -            lrouter_port_ipv4_reachable(op, ipv4_addr)) {
> -            build_lswitch_rport_arp_req_flow(
> -                ip_addr, AF_INET, sw_op, sw_od, 80, lflows,
> -                stage_hint);
> +    const struct lr_lb_nat_data_record *lr_lbnat_rec = NULL;
> +    if (op->od->nbr->n_load_balancer ||
op->od->nbr->n_load_balancer_group) {
> +        lr_lbnat_rec = lr_lb_nat_data_table_find_by_index(lr_lbnats,
> +                                                          op->od->index);
> +        ovs_assert(lr_lbnat_rec);
> +
> +        const char *ip_addr;
> +        SSET_FOR_EACH (ip_addr, &lr_lbnat_rec->lb_ips->ips_v4_reachable)
{
> +            ovs_be32 ipv4_addr;
> +
> +            /* Check if the ovn port has a network configured on which
we could
> +            * expect ARP requests for the LB VIP.
> +            */
> +            if (ip_parse(ip_addr, &ipv4_addr) &&
> +                lrouter_port_ipv4_reachable(op, ipv4_addr)) {
> +                build_lswitch_rport_arp_req_flow(
> +                    ip_addr, AF_INET, sw_op, sw_od, 80, lflows,
> +                    stage_hint);
> +            }
>          }
> -    }
> -    SSET_FOR_EACH (ip_addr, &op->od->lb_ips->ips_v6_reachable) {
> -        struct in6_addr ipv6_addr;
> +        SSET_FOR_EACH (ip_addr, &lr_lbnat_rec->lb_ips->ips_v6_reachable)
{
> +            struct in6_addr ipv6_addr;
>
> -        /* Check if the ovn port has a network configured on which we
could
> -         * expect NS requests for the LB VIP.
> -         */
> -        if (ipv6_parse(ip_addr, &ipv6_addr) &&
> -            lrouter_port_ipv6_reachable(op, &ipv6_addr)) {
> -            build_lswitch_rport_arp_req_flow(
> -                ip_addr, AF_INET6, sw_op, sw_od, 80, lflows,
> -                stage_hint);
> +            /* Check if the ovn port has a network configured on which
we could
> +            * expect NS requests for the LB VIP.
> +            */
> +            if (ipv6_parse(ip_addr, &ipv6_addr) &&
> +                lrouter_port_ipv6_reachable(op, &ipv6_addr)) {
> +                build_lswitch_rport_arp_req_flow(
> +                    ip_addr, AF_INET6, sw_op, sw_od, 80, lflows,
> +                    stage_hint);
> +            }
>          }
>      }
>
> @@ -9374,13 +9091,15 @@ build_lswitch_rport_arp_req_flows(struct ovn_port
*op,
>           * expect ARP requests/NS for the DNAT external_ip.
>           */
>          if (nat_entry_is_v6(nat_entry)) {
> -            if (!sset_contains(&op->od->lb_ips->ips_v6,
nat->external_ip)) {
> +            if (!lr_lbnat_rec ||
!sset_contains(&lr_lbnat_rec->lb_ips->ips_v6,
> +                                            nat->external_ip)) {
>                  build_lswitch_rport_arp_req_flow(
>                      nat->external_ip, AF_INET6, sw_op, sw_od, 80, lflows,
>                      stage_hint);
>              }
>          } else {
> -            if (!sset_contains(&op->od->lb_ips->ips_v4,
nat->external_ip)) {
> +            if (!lr_lbnat_rec ||
!sset_contains(&lr_lbnat_rec->lb_ips->ips_v4,
> +                                            nat->external_ip)) {
>                  build_lswitch_rport_arp_req_flow(
>                      nat->external_ip, AF_INET, sw_op, sw_od, 80, lflows,
>                      stage_hint);
> @@ -10441,6 +10160,7 @@ build_lswitch_ip_mcast_igmp_mld(struct
ovn_igmp_group *igmp_group,
>  static void
>  build_lswitch_ip_unicast_lookup(struct ovn_port *op,
>                                  const struct lr_nat_table *lr_nats,
> +                                const struct lr_lb_nat_data_table
*lr_lbnats,
>                                  struct hmap *lflows,
>                                  struct ds *actions,
>                                  struct ds *match)
> @@ -10456,7 +10176,8 @@ build_lswitch_ip_unicast_lookup(struct ovn_port
*op,
>       */
>      if (lsp_is_router(op->nbsp)) {
>          build_lswitch_rport_arp_req_flows(op->peer, op->od, op, lr_nats,
> -                                          lflows, &op->nbsp->header_);
> +                                          lr_lbnats, lflows,
> +                                          &op->nbsp->header_);
>      }
>
>      for (size_t i = 0; i < op->nbsp->n_addresses; i++) {
> @@ -12646,6 +12367,7 @@ build_lrouter_port_nat_arp_nd_flow(struct
ovn_port *op,
>  static void
>  build_lrouter_drop_own_dest(struct ovn_port *op,
>                              const struct lr_nat_record *lrnat_rec,
> +                            const struct lr_lb_nat_data_record
*lr_lbnat_rec,
>                              enum ovn_stage stage,
>                              uint16_t priority, bool drop_snat_ip,
>                              struct hmap *lflows)
> @@ -12658,8 +12380,9 @@ build_lrouter_drop_own_dest(struct ovn_port *op,
>
>              bool router_ip_in_snat_ips =
!!shash_find(&lrnat_rec->snat_ips,
>                                                        ip);
> -            bool router_ip_in_lb_ips =
> -                    !!sset_find(&op->od->lb_ips->ips_v4, ip);
> +            bool router_ip_in_lb_ips = (lr_lbnat_rec &&
> +
 !!sset_find(&lr_lbnat_rec->lb_ips->ips_v4,
> +                                                ip));
>              bool drop_router_ip = (drop_snat_ip ==
(router_ip_in_snat_ips ||
>
 router_ip_in_lb_ips));
>
> @@ -12688,8 +12411,9 @@ build_lrouter_drop_own_dest(struct ovn_port *op,
>
>              bool router_ip_in_snat_ips =
!!shash_find(&lrnat_rec->snat_ips,
>                                                        ip);
> -            bool router_ip_in_lb_ips =
> -                    !!sset_find(&op->od->lb_ips->ips_v6, ip);
> +            bool router_ip_in_lb_ips = (lr_lbnat_rec &&
> +
 !!sset_find(&lr_lbnat_rec->lb_ips->ips_v6,
> +                                                ip));
>              bool drop_router_ip = (drop_snat_ip ==
(router_ip_in_snat_ips ||
>
 router_ip_in_lb_ips));
>
> @@ -13401,7 +13125,8 @@ build_ip_routing_flows_for_lrp(
>   */
>  static void
>  build_ip_routing_flows_for_router_type_lsp(
> -        struct ovn_port *op, const struct hmap *lr_ports, struct hmap
*lflows)
> +        struct ovn_port *op, const struct lr_lb_nat_data_table
*lr_lbnats,
> +        const struct hmap *lr_ports, struct hmap *lflows)
>  {
>      ovs_assert(op->nbsp);
>      if (!lsp_is_router(op->nbsp)) {
> @@ -13409,7 +13134,8 @@ build_ip_routing_flows_for_router_type_lsp(
>      }
>
>      struct ovn_port *peer = ovn_port_get_peer(lr_ports, op);
> -    if (!peer || !peer->nbrp || !peer->lrp_networks.n_ipv4_addrs) {
> +    if (!peer || !peer->nbrp || !peer->lrp_networks.n_ipv4_addrs
> +        || !op->od->n_router_ports) {
>          return;
>      }
>
> @@ -13420,19 +13146,29 @@ build_ip_routing_flows_for_router_type_lsp(
>              continue;
>          }
>
> -        struct ovn_port_routable_addresses *ra = &router_port->routables;
> -        for (size_t j = 0; j < ra->n_addrs; j++) {
> -            struct lport_addresses *laddrs = &ra->laddrs[j];
> -            for (size_t k = 0; k < laddrs->n_ipv4_addrs; k++) {
> -                add_route(lflows, peer->od, peer,
> -                          peer->lrp_networks.ipv4_addrs[0].addr_s,
> -                          laddrs->ipv4_addrs[k].network_s,
> -                          laddrs->ipv4_addrs[k].plen, NULL, false, 0,
> -                          &peer->nbrp->header_, false,
> -                          ROUTE_PRIO_OFFSET_CONNECTED);
> +        const struct lr_lb_nat_data_record *lr_lbnat_rec =
> +            lr_lb_nat_data_table_find_by_index(lr_lbnats,
> +                                               router_port->od->index);
> +
> +        if (router_port->nbrp->ha_chassis_group ||
> +                router_port->nbrp->n_gateway_chassis) {
> +            struct ovn_port_routable_addresses ra =
> +                get_op_routable_addresses(router_port, lr_lbnat_rec);
> +            for (size_t j = 0; j < ra.n_addrs; j++) {
> +                struct lport_addresses *laddrs = &ra.laddrs[j];
> +                for (size_t k = 0; k < laddrs->n_ipv4_addrs; k++) {
> +                    add_route(lflows, peer->od, peer,
> +                            peer->lrp_networks.ipv4_addrs[0].addr_s,
> +                            laddrs->ipv4_addrs[k].network_s,
> +                            laddrs->ipv4_addrs[k].plen, NULL, false, 0,
> +                            &peer->nbrp->header_, false,
> +                            ROUTE_PRIO_OFFSET_CONNECTED);
> +                }
>              }
> +            destroy_routable_addresses(&ra);
>          }
>      }
> +
>  }
>
>  static void
> @@ -13656,33 +13392,36 @@ build_arp_resolve_flows_for_lrouter(
>
>  static void
>  routable_addresses_to_lflows(struct hmap *lflows, struct ovn_port
*router_port,
> -                             struct ovn_port *peer, struct ds *match,
> -                             struct ds *actions)
> +                             struct ovn_port *peer,
> +                             const struct lr_lb_nat_data_record
*lr_lbnat_rec,
> +                             struct ds *match, struct ds *actions)
>  {
> -    struct ovn_port_routable_addresses *ra = &router_port->routables;
> -    if (!ra->n_addrs) {
> +    struct ovn_port_routable_addresses ra =
> +        get_op_routable_addresses(router_port, lr_lbnat_rec);
> +    if (!ra.n_addrs) {
>          return;
>      }
>
> -    for (size_t i = 0; i < ra->n_addrs; i++) {
> +    for (size_t i = 0; i < ra.n_addrs; i++) {
>          ds_clear(match);
>          ds_put_format(match, "outport == %s && "REG_NEXT_HOP_IPV4" == {",
>                        peer->json_key);
>          bool first = true;
> -        for (size_t j = 0; j < ra->laddrs[i].n_ipv4_addrs; j++) {
> +        for (size_t j = 0; j < ra.laddrs[i].n_ipv4_addrs; j++) {
>              if (!first) {
>                  ds_put_cstr(match, ", ");
>              }
> -            ds_put_cstr(match, ra->laddrs[i].ipv4_addrs[j].addr_s);
> +            ds_put_cstr(match, ra.laddrs[i].ipv4_addrs[j].addr_s);
>              first = false;
>          }
>          ds_put_cstr(match, "}");
>
>          ds_clear(actions);
> -        ds_put_format(actions, "eth.dst = %s; next;",
ra->laddrs[i].ea_s);
> +        ds_put_format(actions, "eth.dst = %s; next;", ra.laddrs[i].ea_s);
>          ovn_lflow_add(lflows, peer->od, S_ROUTER_IN_ARP_RESOLVE, 100,
>                        ds_cstr(match), ds_cstr(actions));
>      }
> +    destroy_routable_addresses(&ra);
>  }
>
>  /* Local router ingress table ARP_RESOLVE: ARP Resolution.
> @@ -13699,6 +13438,7 @@ routable_addresses_to_lflows(struct hmap *lflows,
struct ovn_port *router_port,
>  static void
>  build_arp_resolve_flows_for_lrp(
>          struct ovn_port *op, const struct lr_nat_record *lrnat_rec,
> +        const struct lr_lb_nat_data_record *lr_lbnat_rec,
>          struct hmap *lflows, struct ds *match, struct ds *actions)
>  {
>      ovs_assert(op->nbrp);
> @@ -13775,8 +13515,8 @@ build_arp_resolve_flows_for_lrp(
>       *
>       * Priority 2.
>       */
> -    build_lrouter_drop_own_dest(op, lrnat_rec, S_ROUTER_IN_ARP_RESOLVE,
2,
> -                                true, lflows);
> +    build_lrouter_drop_own_dest(op, lrnat_rec, lr_lbnat_rec,
> +                                S_ROUTER_IN_ARP_RESOLVE, 2, true,
lflows);
>  }
>
>  /* This function adds ARP resolve flows related to a LSP. */
> @@ -13784,6 +13524,7 @@ static void
>  build_arp_resolve_flows_for_lsp(
>          struct ovn_port *op, struct hmap *lflows,
>          const struct hmap *lr_ports,
> +        const struct lr_lb_nat_data_table *lr_lbnats,
>          struct ds *match, struct ds *actions)
>  {
>      ovs_assert(op->nbsp);
> @@ -13927,8 +13668,11 @@ build_arp_resolve_flows_for_lsp(
>
>              if (smap_get(&peer->od->nbr->options, "chassis")
>                  || peer->cr_port) {
> +                const struct lr_lb_nat_data_record *lr_lbnat_rec;
> +                lr_lbnat_rec =
lr_lb_nat_data_table_find_by_index(lr_lbnats,
> +
 router_port->od->index);
>                  routable_addresses_to_lflows(lflows, router_port, peer,
> -                                             match, actions);
> +                                             lr_lbnat_rec, match,
actions);
>              }
>          }
>      }
> @@ -14648,6 +14392,7 @@ static void
>  build_lrouter_ipv4_ip_input(struct ovn_port *op,
>                              struct hmap *lflows,
>                              const struct lr_nat_record *lrnat_rec,
> +                            const struct lr_lb_nat_data_record
*lr_lbnat_rec,
>                              struct ds *match, struct ds *actions,
>                              const struct shash *meter_groups)
>  {
> @@ -14772,7 +14517,7 @@ build_lrouter_ipv4_ip_input(struct ovn_port *op,
>                                 &op->nbrp->header_, lflows);
>      }
>
> -    if (sset_count(&op->od->lb_ips->ips_v4_reachable)) {
> +    if (lr_lbnat_rec &&
sset_count(&lr_lbnat_rec->lb_ips->ips_v4_reachable)) {
>          ds_clear(match);
>          if (is_l3dgw_port(op)) {
>              ds_put_format(match, "is_chassis_resident(%s)",
> @@ -14788,7 +14533,7 @@ build_lrouter_ipv4_ip_input(struct ovn_port *op,
>          free(lb_ips_v4_as);
>      }
>
> -    if (sset_count(&op->od->lb_ips->ips_v6_reachable)) {
> +    if (lr_lbnat_rec &&
sset_count(&lr_lbnat_rec->lb_ips->ips_v6_reachable)) {
>          ds_clear(match);
>
>          if (is_l3dgw_port(op)) {
> @@ -14890,8 +14635,8 @@ build_lrouter_ipv4_ip_input(struct ovn_port *op,
>       * Priority 60.
>       */
>      if (!lrnat_rec->lb_force_snat_router_ip) {
> -        build_lrouter_drop_own_dest(op, lrnat_rec, S_ROUTER_IN_IP_INPUT,
60,
> -                                    false, lflows);
> +        build_lrouter_drop_own_dest(op, lrnat_rec, lr_lbnat_rec,
> +                                    S_ROUTER_IN_IP_INPUT, 60, false,
lflows);
>      }
>      /* ARP / ND handling for external IP addresses.
>       *
> @@ -16030,6 +15775,7 @@ struct lswitch_flow_build_info {
>      const struct hmap *lr_ports;
>      const struct ls_port_group_table *ls_port_groups;
>      const struct lr_nat_table *lr_nats;
> +    const struct lr_lb_nat_data_table *lr_lbnats;
>      struct hmap *lflows;
>      struct hmap *igmp_groups;
>      const struct shash *meter_groups;
> @@ -16113,14 +15859,15 @@ build_lswitch_and_lrouter_iterate_by_lr(struct
ovn_datapath *od,
>   * switch port.
>   */
>  static void
> -build_lswitch_and_lrouter_iterate_by_lsp(struct ovn_port *op,
> -                                         const struct hmap *ls_ports,
> -                                         const struct hmap *lr_ports,
> -                                         const struct lr_nat_table
*lr_nats,
> -                                         const struct shash
*meter_groups,
> -                                         struct ds *match,
> -                                         struct ds *actions,
> -                                         struct hmap *lflows)
> +build_lswitch_and_lrouter_iterate_by_lsp(
> +    struct ovn_port *op, const struct hmap *ls_ports,
> +    const struct hmap *lr_ports,
> +    const struct lr_nat_table *lr_nats,
> +    const struct lr_lb_nat_data_table *lr_lbnats,
> +    const struct shash *meter_groups,
> +    struct ds *match,
> +    struct ds *actions,
> +    struct hmap *lflows)
>  {
>      ovs_assert(op->nbsp);
>      start_collecting_lflows();
> @@ -16133,11 +15880,14 @@ build_lswitch_and_lrouter_iterate_by_lsp(struct
ovn_port *op,
>                                               meter_groups, actions,
match);
>      build_lswitch_dhcp_options_and_response(op, lflows, meter_groups);
>      build_lswitch_external_port(op, lflows);
> -    build_lswitch_ip_unicast_lookup(op, lr_nats, lflows, actions, match);
> +    build_lswitch_ip_unicast_lookup(op, lr_nats, lr_lbnats, lflows,
actions,
> +                                    match);
>
>      /* Build Logical Router Flows. */
> -    build_ip_routing_flows_for_router_type_lsp(op, lr_ports, lflows);
> -    build_arp_resolve_flows_for_lsp(op, lflows, lr_ports, match,
actions);
> +    build_ip_routing_flows_for_router_type_lsp(op, lr_lbnats, lr_ports,
> +                                               lflows);
> +    build_arp_resolve_flows_for_lsp(op, lflows, lr_ports, lr_lbnats,
> +                                    match, actions);
>
>      link_ovn_port_to_lflows(op, &collected_lflows);
>      end_collecting_lflows();
> @@ -16156,6 +15906,8 @@ build_lswitch_and_lrouter_iterate_by_lrp(struct
ovn_port *op,
>          lsi->lr_nats, op->od->index);
>      ovs_assert(lrnet_rec);
>
> +    const struct lr_lb_nat_data_record *lr_lbnat_rec =
> +        lr_lb_nat_data_table_find_by_index(lsi->lr_lbnats,
op->od->index);
>      build_adm_ctrl_flows_for_lrouter_port(op, lsi->lflows, &lsi->match,
>                                            &lsi->actions);
>      build_neigh_learning_flows_for_lrouter_port(op, lsi->lflows,
&lsi->match,
> @@ -16163,15 +15915,15 @@ build_lswitch_and_lrouter_iterate_by_lrp(struct
ovn_port *op,
>      build_ip_routing_flows_for_lrp(op, lsi->lflows);
>      build_ND_RA_flows_for_lrouter_port(op, lsi->lflows, &lsi->match,
>                                         &lsi->actions, lsi->meter_groups);
> -    build_arp_resolve_flows_for_lrp(op, lrnet_rec, lsi->lflows,
&lsi->match,
> -                                    &lsi->actions);
> +    build_arp_resolve_flows_for_lrp(op, lrnet_rec, lr_lbnat_rec,
lsi->lflows,
> +                                    &lsi->match, &lsi->actions);
>      build_egress_delivery_flows_for_lrouter_port(op, lsi->lflows,
&lsi->match,
>                                                   &lsi->actions);
>      build_dhcpv6_reply_flows_for_lrouter_port(op, lsi->lflows,
&lsi->match);
>      build_ipv6_input_flows_for_lrouter_port(op, lsi->lflows,
>                                              &lsi->match, &lsi->actions,
>                                              lsi->meter_groups);
> -    build_lrouter_ipv4_ip_input(op, lsi->lflows, lrnet_rec,
> +    build_lrouter_ipv4_ip_input(op, lsi->lflows, lrnet_rec, lr_lbnat_rec,
>                                  &lsi->match, &lsi->actions,
lsi->meter_groups);
>      build_lrouter_force_snat_flows_op(op, lrnet_rec, lsi->lflows,
&lsi->match,
>                                        &lsi->actions);
> @@ -16234,6 +15986,7 @@ build_lflows_thread(void *arg)
>                      build_lswitch_and_lrouter_iterate_by_lsp(op,
lsi->ls_ports,
>
lsi->lr_ports,
>
lsi->lr_nats,
> +
lsi->lr_lbnats,
>
lsi->meter_groups,
>                                                               &lsi->match,
>
&lsi->actions,
> @@ -16344,6 +16097,7 @@ build_lswitch_and_lrouter_flows(const struct
ovn_datapaths *ls_datapaths,
>                                  const struct hmap *lr_ports,
>                                  const struct ls_port_group_table *ls_pgs,
>                                  const struct lr_nat_table *lr_nats,
> +                                const struct lr_lb_nat_data_table
*lr_lbnats,
>                                  struct hmap *lflows,
>                                  struct hmap *igmp_groups,
>                                  const struct shash *meter_groups,
> @@ -16374,6 +16128,7 @@ build_lswitch_and_lrouter_flows(const struct
ovn_datapaths *ls_datapaths,
>              lsiv[index].lr_ports = lr_ports;
>              lsiv[index].ls_port_groups = ls_pgs;
>              lsiv[index].lr_nats = lr_nats;
> +            lsiv[index].lr_lbnats = lr_lbnats;
>              lsiv[index].igmp_groups = igmp_groups;
>              lsiv[index].meter_groups = meter_groups;
>              lsiv[index].lb_dps_map = lb_dps_map;
> @@ -16409,6 +16164,7 @@ build_lswitch_and_lrouter_flows(const struct
ovn_datapaths *ls_datapaths,
>              .lr_ports = lr_ports,
>              .ls_port_groups = ls_pgs,
>              .lr_nats = lr_nats,
> +            .lr_lbnats = lr_lbnats,
>              .lflows = lflows,
>              .igmp_groups = igmp_groups,
>              .meter_groups = meter_groups,
> @@ -16437,6 +16193,7 @@ build_lswitch_and_lrouter_flows(const struct
ovn_datapaths *ls_datapaths,
>              build_lswitch_and_lrouter_iterate_by_lsp(op, lsi.ls_ports,
>                                                       lsi.lr_ports,
>                                                       lsi.lr_nats,
> +                                                     lsi.lr_lbnats,
>                                                       lsi.meter_groups,
>                                                       &lsi.match,
&lsi.actions,
>                                                       lsi.lflows);
> @@ -16558,6 +16315,7 @@ void build_lflows(struct ovsdb_idl_txn *ovnsb_txn,
>                                      input_data->lr_ports,
>                                      input_data->ls_port_groups,
>                                      input_data->lr_nats,
> +                                    input_data->lr_lbnats,
>                                      lflows,
>                                      &igmp_groups,
>                                      input_data->meter_groups,
> @@ -17038,6 +16796,7 @@ lflow_handle_northd_port_changes(struct
ovsdb_idl_txn *ovnsb_txn,
>          build_lswitch_and_lrouter_iterate_by_lsp(op,
lflow_input->ls_ports,
>                                                   lflow_input->lr_ports,
>                                                   lflow_input->lr_nats,
> +                                                 lflow_input->lr_lbnats,
>
lflow_input->meter_groups,
>                                                   &match, &actions,
>                                                   lflows);
> @@ -17076,6 +16835,7 @@ lflow_handle_northd_port_changes(struct
ovsdb_idl_txn *ovnsb_txn,
>          build_lswitch_and_lrouter_iterate_by_lsp(op,
lflow_input->ls_ports,
>
 lflow_input->lr_ports,
>                                                      lflow_input->lr_nats,
> +
 lflow_input->lr_lbnats,
>
 lflow_input->meter_groups,
>                                                      &match, &actions,
>                                                      lflows);
> diff --git a/northd/northd.h b/northd/northd.h
> index 564729ebcc..7c446f5758 100644
> --- a/northd/northd.h
> +++ b/northd/northd.h
> @@ -179,6 +179,7 @@ struct lflow_input {
>      const struct hmap *lr_ports;
>      const struct ls_port_group_table *ls_port_groups;
>      const struct lr_nat_table *lr_nats;
> +    const struct lr_lb_nat_data_table *lr_lbnats;
>      const struct shash *meter_groups;
>      const struct hmap *lb_datapaths_map;
>      const struct hmap *bfd_connections;
> @@ -318,9 +319,6 @@ struct ovn_datapath {
>      /* router datapath has a logical port with redirect-type set to
bridged. */
>      bool redirect_bridged;
>
> -    /* Load Balancer vIPs relevant for this datapath. */
> -    struct ovn_lb_ip_set *lb_ips;
> -
>      struct ovn_port **localnet_ports;
>      size_t n_localnet_ports;
>
> @@ -337,6 +335,119 @@ struct ovn_datapath {
>  const struct ovn_datapath *ovn_datapath_find(const struct hmap
*datapaths,
>                                               const struct uuid *uuid);
>
> +/* A logical switch port or logical router port.
> + *
> + * In steady state, an ovn_port points to a northbound
Logical_Switch_Port
> + * record (via 'nbsp') *or* a Logical_Router_Port record (via 'nbrp'),
and to a
> + * southbound Port_Binding record (via 'sb').  As the state of the system
> + * changes, join_logical_ports() may determine that there is a new LSP
or LRP
> + * that has no corresponding Port_Binding record (in which case
build_ports())
> + * will create the missing Port_Binding) or that a Port_Binding record
exists
> + * that has no coresponding LSP (in which case build_ports() will delete
the
> + * spurious Port_Binding).  Thus, after build_ports() runs, any given
ovn_port
> + * will have 'sb' nonnull, and 'nbsp' xor 'nbrp' nonnull.
> + *
> + * Ordinarily there is only one ovn_port that points to a given LSP or
LRP (but
> + * distributed gateway ports point a "derived" ovn_port to a duplicate
LRP).
> + */
> +struct ovn_port {
> +    /* Port name aka key.
> +     *
> +     * This is ordinarily the same as nbsp->name or nbrp->name and
> +     * sb->logical_port.  (A distributed gateway port creates a "derived"
> +     * ovn_port with key "cr-%s" % nbrp->name.) */
> +    struct hmap_node key_node;  /* Index on 'key'. */
> +    char *key;                  /* nbsp->name, nbrp->name,
sb->logical_port. */
> +    char *json_key;             /* 'key', quoted for use in JSON. */
> +
> +    const struct sbrec_port_binding *sb;         /* May be NULL. */
> +
> +    uint32_t tunnel_key;
> +
> +    /* Logical switch port data. */
> +    const struct nbrec_logical_switch_port *nbsp; /* May be NULL. */
> +
> +    struct lport_addresses *lsp_addrs;  /* Logical switch port
addresses. */
> +    unsigned int n_lsp_addrs;  /* Total length of lsp_addrs. */
> +    unsigned int n_lsp_non_router_addrs; /* Number of elements from the
> +                                          * beginning of 'lsp_addrs'
extracted
> +                                          * directly from LSP
'addresses'. */
> +
> +    struct lport_addresses *ps_addrs;   /* Port security addresses. */
> +    unsigned int n_ps_addrs;
> +
> +    bool lsp_can_be_inc_processed; /* If it can be incrementally
processed when
> +                                      the port changes. */
> +
> +    /* Logical router port data. */
> +    const struct nbrec_logical_router_port *nbrp; /* May be NULL. */
> +
> +    struct lport_addresses lrp_networks;
> +
> +    /* Logical port multicast data. */
> +    struct mcast_port_info mcast_info;
> +
> +    /* At most one of l3dgw_port and cr_port can be not NULL. */
> +
> +    /* This is set to a distributed gateway port if and only if this
ovn_port
> +     * is "derived" from it. Otherwise this is set to NULL. The derived
> +     * ovn_port represents the instance of distributed gateway port on
the
> +     * gateway chassis.*/
> +    struct ovn_port *l3dgw_port;
> +
> +    /* This is set to the "derived" chassis-redirect port of this port
if and
> +     * only if this port is a distributed gateway port. Otherwise this
is set
> +     * to NULL. */
> +    struct ovn_port *cr_port;
> +
> +    bool has_unknown; /* If the addresses have 'unknown' defined. */
> +
> +    bool has_bfd;
> +
> +    /* The port's peer:
> +     *
> +     *     - A switch port S of type "router" has a router port R as a
peer,
> +     *       and R in turn has S has its peer.
> +     *
> +     *     - Two connected logical router ports have each other as peer.
> +     *
> +     *     - Other kinds of ports have no peer. */
> +    struct ovn_port *peer;
> +
> +    struct ovn_datapath *od;
> +
> +    struct ovs_list list;       /* In list of similar records. */
> +
> +    struct hmap_node dp_node;   /* Node in od->ports. */
> +
> +    struct lport_addresses proxy_arp_addrs;
> +
> +    /* Temporarily used for traversing a list (or hmap) of ports. */
> +    bool visited;
> +
> +    /* List of struct lflow_ref_node that points to the lflows generated
by
> +     * this ovn_port.
> +     *
> +     * This data is initialized and destroyed by the en_northd node, but
> +     * populated and used only by the en_lflow node. Ideally this data
should
> +     * be maintained as part of en_lflow's data (struct lflow_data): a
hash
> +     * index from ovn_port key to lflows.  However, it would be less
efficient
> +     * and more complex:
> +     *
> +     * 1. It would require an extra search (using the index) to find the
> +     * lflows.
> +     *
> +     * 2. Building the index needs to be thread-safe, using either a
global
> +     * lock which is obviously less efficient, or hash-based lock array
which
> +     * is more complex.
> +     *
> +     * Adding the list here is more straightforward. The drawback is
that we
> +     * need to keep in mind that this data belongs to en_lflow node, so
never
> +     * access it from any other nodes.
> +     */
> +    struct ovs_list lflows;
> +};
> +
>  void ovnnb_db_run(struct northd_input *input_data,
>                    struct northd_data *data,
>                    struct ovsdb_idl_txn *ovnnb_txn,
> @@ -396,13 +507,27 @@ void sync_lbs(struct ovsdb_idl_txn *, const struct
sbrec_load_balancer_table *,
>                struct chassis_features *chassis_features);
>  bool check_sb_lb_duplicates(const struct sbrec_load_balancer_table *);
>
> +struct lr_lb_nat_data_table;
>  void sync_pbs(struct ovsdb_idl_txn *, struct hmap *ls_ports,
> -              struct hmap *lr_ports, const struct lr_nat_table *);
> -bool sync_pbs_for_northd_changed_ovn_ports(struct tracked_ovn_ports *,
> -                                           const struct lr_nat_table *);
> +              struct hmap *lr_ports,
> +              const struct lr_lb_nat_data_table *);
> +bool sync_pbs_for_northd_changed_ovn_ports(
> +    struct tracked_ovn_ports *,
> +    const struct lr_lb_nat_data_table *);
>
>  bool northd_has_tracked_data(struct northd_tracked_data *);
>  bool northd_has_only_ports_in_tracked_data(struct northd_tracked_data *);
>  bool northd_has_lbs_in_tracked_data(struct northd_tracked_data *);
>
> +/* Returns 'true' if the IPv4 'addr' is on the same subnet with one of
the
> + * IPs configured on the router port.
> + */
> +bool lrouter_port_ipv4_reachable(const struct ovn_port *, ovs_be32 addr);
> +
> +/* Returns 'true' if the IPv6 'addr' is on the same subnet with one of
the
> + * IPs configured on the router port.
> + */
> +bool lrouter_port_ipv6_reachable(const struct ovn_port *,
> +                                 const struct in6_addr *);
> +
>  #endif /* NORTHD_H */
> diff --git a/tests/ovn-northd.at b/tests/ovn-northd.at
> index b7f9cb5689..8fc5cd1d60 100644
> --- a/tests/ovn-northd.at
> +++ b/tests/ovn-northd.at
> @@ -10416,18 +10416,21 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb set load_balancer .
ip_port_mappings:10.0.0.3=sw0-p1:10.0.0.2
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>
>  check ovn-nbctl --wait=sb set load_balancer . options:foo=bar
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>
>  check ovn-nbctl --wait=sb -- lb-add lb2 20.0.0.10:80 20.0.0.20:80 --
lb-add lb3 30.0.0.10:80 30.0.0.20:80
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>
> @@ -10437,6 +10440,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb -- lb-del lb2 -- lb-del lb3
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>
> @@ -10450,6 +10454,7 @@ AT_CHECK([ovn-nbctl --wait=sb \
>  ])
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>
> @@ -10467,6 +10472,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb clear Load_Balancer . health_check
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>
> @@ -10481,6 +10487,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  ovn-nbctl --wait=sb lsp-set-options sw0-lr0 router-port=lr0-sw0
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>
> @@ -10489,6 +10496,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb ls-lb-add sw0 lb1
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  # A LB applied to a switch/router triggers:
>  # - a recompute in the first iteration (handling northd change)
> @@ -10501,6 +10509,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb set load_balancer lb1 vips:'"10.0.0.10:80"'='"
10.0.0.100:80"'
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10510,6 +10519,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb clear load_Balancer lb1 vips
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10519,6 +10529,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lb-add lb1 10.0.0.10:80 10.0.0.3:80
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10528,6 +10539,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lb-add lb1 10.0.0.20:80 10.0.0.30:8080
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10537,6 +10549,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb ls-lb-del sw0 lb1
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10547,6 +10560,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb ls-lb-add sw0 lb1 -- lsp-add sw0 sw0p1
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>
> @@ -10567,6 +10581,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lr-lb-add lr0 lb1
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10576,6 +10591,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb set load_balancer lb1 vips:'"10.0.0.10:80"'='"
10.0.0.100:80"'
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10585,6 +10601,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb clear load_Balancer lb1 vips
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10594,6 +10611,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lb-add lb1 10.0.0.10:80 10.0.0.3:80
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10603,6 +10621,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lb-add lb1 10.0.0.20:80 10.0.0.30:8080
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10632,6 +10651,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb add load_balancer_group . load_Balancer
$lb1_uuid
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>
> @@ -10639,6 +10659,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb clear load_balancer_group . load_Balancer
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>
> @@ -10655,6 +10676,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb add logical_switch sw0 load_balancer_group
$lbg1_uuid
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>
> @@ -10671,6 +10693,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb set load_balancer lb1 vips:'"10.0.0.10:80"'='"
10.0.0.100:80"'
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10680,6 +10703,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb clear load_Balancer lb1 vips
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10689,6 +10713,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lb-add lb1 10.0.0.10:80 10.0.0.3:80
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10698,6 +10723,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lb-add lb1 10.0.0.20:80 10.0.0.30:8080
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10713,6 +10739,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl add logical_router lr0 load_balancer_group $lbg1_uuid
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10722,6 +10749,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb set load_balancer lb1 vips:'"10.0.0.10:80"'='"
10.0.0.100:80"'
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10731,6 +10759,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb clear load_Balancer lb1 vips
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10740,6 +10769,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lb-add lb1 10.0.0.10:80 10.0.0.3:80
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10749,6 +10779,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lb-add lb1 10.0.0.20:80 10.0.0.30:8080
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10757,6 +10788,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb clear logical_router lr0 load_balancer_group
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>
> @@ -10765,6 +10797,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb add logical_switch sw0 load_balancer_group
$lbg1_uuid
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>
> @@ -10773,6 +10806,7 @@ check ovn-nbctl --wait=sb clear logical_switch
sw0 load_balancer_group -- \
>      destroy load_balancer_group $lbg1_uuid
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb compute compute
>
> @@ -10796,6 +10830,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  lbg1_uuid=$(ovn-nbctl --wait=sb create load_balancer_group name=lbg1)
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow norecompute nocompute
>  check_engine_stats sync_to_sb_lb norecompute nocompute
>
> @@ -10803,6 +10838,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb set load_balancer_group .
load_balancer="$lb2_uuid,$lb3_uuid,$lb4_uuid"
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>
> @@ -10810,6 +10846,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb set logical_switch sw0
load_balancer_group=$lbg1_uuid
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10818,6 +10855,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb set logical_router lr1
load_balancer_group=$lbg1_uuid
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10826,6 +10864,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb ls-lb-add sw0 lb2
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10834,6 +10873,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb ls-lb-add sw0 lb3
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10843,6 +10883,7 @@ check ovn-nbctl --wait=sb lr-lb-add lr1 lb1
>  check ovn-nbctl --wait=sb lr-lb-add lr1 lb2
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10851,6 +10892,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb ls-lb-del sw0 lb2
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10859,6 +10901,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lr-lb-del lr1 lb2
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10869,6 +10912,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lb-del lb4
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10879,6 +10923,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lb-del lb2
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10887,6 +10932,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb remove load_balancer_group . load_balancer
$lb3_uuid
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11019,6 +11065,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lr-add lr0
>  check_engine_stats northd recompute nocompute
>  check_engine_stats lr_nat recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11031,6 +11078,7 @@ check ovn-nbctl lrp-add lr0 lr0-sw0
00:00:00:00:ff:01 10.0.0.1/24
>  # for the SB port binding change.
>  check_engine_stats northd recompute compute
>  check_engine_stats lr_nat recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11042,6 +11090,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lsp-set-options sw0-lr0 router-port=lr0-sw0
>  check_engine_stats northd recompute nocompute
>  check_engine_stats lr_nat recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11067,6 +11116,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl set logical_router_port lr0-sw0 options:foo=bar
>  check_engine_stats northd recompute nocompute
>  check_engine_stats lr_nat recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11076,8 +11126,8 @@ CHECK_NO_CHANGE_AFTER_RECOMPUTE
>  # engine nodes.
>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lr-nat-add lr0 dnat_and_snat  172.168.0.110
10.0.0.4
> -check_engine_stats northd recompute nocompute
> -check_engine_stats lr_nat recompute nocompute
> +check_engine_stats northd norecompute compute
> +check_engine_stats lr_nat norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11085,8 +11135,8 @@ CHECK_NO_CHANGE_AFTER_RECOMPUTE
>  # Update the NAT options column
>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb set NAT . options:foo=bar
> -check_engine_stats northd recompute nocompute
> -check_engine_stats lr_nat recompute nocompute
> +check_engine_stats northd norecompute compute
> +check_engine_stats lr_nat norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11094,8 +11144,9 @@ CHECK_NO_CHANGE_AFTER_RECOMPUTE
>  # Update the NAT external_ip column
>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb set NAT . external_ip=172.168.0.120
> -check_engine_stats northd recompute nocompute
> -check_engine_stats lr_nat recompute nocompute
> +check_engine_stats northd norecompute compute
> +check_engine_stats lr_nat norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11103,8 +11154,9 @@ CHECK_NO_CHANGE_AFTER_RECOMPUTE
>  # Update the NAT logical_ip column
>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb set NAT . logical_ip=10.0.0.10
> -check_engine_stats northd recompute nocompute
> -check_engine_stats lr_nat recompute nocompute
> +check_engine_stats northd norecompute compute
> +check_engine_stats lr_nat norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11112,8 +11164,9 @@ CHECK_NO_CHANGE_AFTER_RECOMPUTE
>  # Update the NAT type
>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb set NAT . type=snat
> -check_engine_stats northd recompute nocompute
> -check_engine_stats lr_nat recompute nocompute
> +check_engine_stats northd norecompute compute
> +check_engine_stats lr_nat norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11121,8 +11174,9 @@ CHECK_NO_CHANGE_AFTER_RECOMPUTE
>  # Create a dnat_and_snat NAT with external_mac and logical_port
>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lr-nat-add lr0 dnat_and_snat 172.168.0.110
10.0.0.4 sw0p1 30:54:00:00:00:03
> -check_engine_stats northd recompute compute
> -check_engine_stats lr_nat recompute nocompute
> +check_engine_stats northd norecompute compute
> +check_engine_stats lr_nat norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11131,8 +11185,9 @@ nat2_uuid=$(ovn-nbctl --bare --columns _uuid find
nat logical_ip=10.0.0.4)
>
>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb set NAT $nat2_uuid
external_mac='"30:54:00:00:00:04"'
> -check_engine_stats northd recompute nocompute
> -check_engine_stats lr_nat recompute nocompute
> +check_engine_stats northd norecompute compute
> +check_engine_stats lr_nat norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11147,32 +11202,36 @@ check ovn-nbctl lr-lb-add lr0 lb2
>  # is a lb vip.
>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lr-nat-add lr0 dnat_and_snat 172.168.0.140
10.0.0.20
> -check_engine_stats northd recompute nocompute
> -check_engine_stats lr_nat recompute nocompute
> +check_engine_stats northd norecompute compute
> +check_engine_stats lr_nat norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>
>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lr-nat-add lr0 dnat_and_snat 172.168.0.150
10.0.0.41
> -check_engine_stats northd recompute nocompute
> -check_engine_stats lr_nat recompute nocompute
> +check_engine_stats northd norecompute compute
> +check_engine_stats lr_nat norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>
>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lr-nat-del lr0 dnat_and_snat 172.168.0.150
> -check_engine_stats northd recompute nocompute
> -check_engine_stats lr_nat recompute nocompute
> +check_engine_stats northd norecompute compute
> +check_engine_stats lr_nat norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>
>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lr-nat-del lr0 dnat_and_snat 172.168.0.140
> -check_engine_stats northd recompute nocompute
> -check_engine_stats lr_nat recompute nocompute
> +check_engine_stats northd norecompute compute
> +check_engine_stats lr_nat norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11180,8 +11239,9 @@ CHECK_NO_CHANGE_AFTER_RECOMPUTE
>  # Delete the NAT
>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb clear logical_router lr0 nat
> -check_engine_stats northd recompute compute
> -check_engine_stats lr_nat recompute nocompute
> +check_engine_stats northd norecompute compute
> +check_engine_stats lr_nat norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11191,6 +11251,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lr-policy-add lr0  10 "ip4.src == 10.0.0.3"
reroute 172.168.0.101,172.168.0.102
>  check_engine_stats northd recompute nocompute
>  check_engine_stats lr_nat recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11199,6 +11260,7 @@ check as northd ovn-appctl -t NORTHD_TYPE
inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lr-policy-del lr0  10 "ip4.src == 10.0.0.3"
>  check_engine_stats northd recompute nocompute
>  check_engine_stats lr_nat recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> --
> 2.41.0
>
> _______________________________________________
> dev mailing list
> dev@openvswitch.org
> https://mail.openvswitch.org/mailman/listinfo/ovs-dev

On 10/26/23 20:15, numans@ovn.org wrote:
> From: Numan Siddique <numans@ovn.org>
> 
> This new engine now maintains the load balancer and NAT data of a
> logical router which was earlier part of northd engine node data.
> The main inputs to this engine are:
>    - northd node
>    - lr-nat node
> 
> A record for each logical router is maintained in the 'lr_lb_nats'
> hmap table and this record
>    - stores the lb related data
>    - embeds the 'lr-nat' record.
> 
> This engine node becomes an input to 'lflow' node.
> 
> Signed-off-by: Numan Siddique <numans@ovn.org>
> ---
>  lib/stopwatch-names.h      |   1 +
>  northd/automake.mk         |   2 +
>  northd/en-lflow.c          |   4 +
>  northd/en-lr-lb-nat-data.c | 654 +++++++++++++++++++++++++++++++++++++
>  northd/en-lr-lb-nat-data.h |  93 ++++++
>  northd/en-lr-nat.h         |   3 +
>  northd/en-sync-sb.c        |  50 +--
>  northd/inc-proc-northd.c   |  13 +-
>  northd/northd.c            | 640 ++++++++++++------------------------
>  northd/northd.h            | 137 +++++++-
>  tests/ovn-northd.at        | 110 +++++--
>  11 files changed, 1212 insertions(+), 495 deletions(-)
>  create mode 100644 northd/en-lr-lb-nat-data.c
>  create mode 100644 northd/en-lr-lb-nat-data.h
> 
> diff --git a/lib/stopwatch-names.h b/lib/stopwatch-names.h
> index 0a16da211e..7d85acdaea 100644
> --- a/lib/stopwatch-names.h
> +++ b/lib/stopwatch-names.h
> @@ -33,5 +33,6 @@
>  #define PORT_GROUP_RUN_STOPWATCH_NAME "port_group_run"
>  #define SYNC_METERS_RUN_STOPWATCH_NAME "sync_meters_run"
>  #define LR_NAT_RUN_STOPWATCH_NAME "lr_nat_run"
> +#define LR_LB_NAT_DATA_RUN_STOPWATCH_NAME "lr_lb_nat_data"
>  
>  #endif
> diff --git a/northd/automake.mk b/northd/automake.mk
> index ae367a2a8b..4116c487df 100644
> --- a/northd/automake.mk
> +++ b/northd/automake.mk
> @@ -26,6 +26,8 @@ northd_ovn_northd_SOURCES = \
>  	northd/en-lb-data.h \
>  	northd/en-lr-nat.c \
>  	northd/en-lr-nat.h \
> +	northd/en-lr-lb-nat-data.c \
> +	northd/en-lr-lb-nat-data.h \
>  	northd/inc-proc-northd.c \
>  	northd/inc-proc-northd.h \
>  	northd/ipam.c \
> diff --git a/northd/en-lflow.c b/northd/en-lflow.c
> index 22f398d419..9cb0ead3f0 100644
> --- a/northd/en-lflow.c
> +++ b/northd/en-lflow.c
> @@ -20,6 +20,7 @@
>  
>  #include "en-lflow.h"
>  #include "en-lr-nat.h"
> +#include "en-lr-lb-nat-data.h"
>  #include "en-northd.h"
>  #include "en-meters.h"
>  
> @@ -43,6 +44,8 @@ lflow_get_input_data(struct engine_node *node,
>          engine_get_input_data("sync_meters", node);
>      struct ed_type_lr_nat_data *lr_nat_data =
>          engine_get_input_data("lr_nat", node);
> +    struct ed_type_lr_lb_nat_data *lr_lb_nat_data =
> +        engine_get_input_data("lr_lb_nat_data", node);
>  
>      lflow_input->nbrec_bfd_table =
>          EN_OVSDB_GET(engine_get_input("NB_bfd", node));
> @@ -66,6 +69,7 @@ lflow_get_input_data(struct engine_node *node,
>      lflow_input->lr_ports = &northd_data->lr_ports;
>      lflow_input->ls_port_groups = &pg_data->ls_port_groups;
>      lflow_input->lr_nats = &lr_nat_data->lr_nats;
> +    lflow_input->lr_lbnats = &lr_lb_nat_data->lr_lbnats;
>      lflow_input->meter_groups = &sync_meters_data->meter_groups;
>      lflow_input->lb_datapaths_map = &northd_data->lb_datapaths_map;
>      lflow_input->svc_monitor_map = &northd_data->svc_monitor_map;
> diff --git a/northd/en-lr-lb-nat-data.c b/northd/en-lr-lb-nat-data.c
> new file mode 100644
> index 0000000000..19b638ce0b
> --- /dev/null
> +++ b/northd/en-lr-lb-nat-data.c
> @@ -0,0 +1,654 @@
> +/*
> + * Copyright (c) 2023, Red Hat, Inc.
> + *
> + * Licensed under the Apache License, Version 2.0 (the "License");
> + * you may not use this file except in compliance with the License.
> + * You may obtain a copy of the License at:
> + *
> + *     http://www.apache.org/licenses/LICENSE-2.0
> + *
> + * Unless required by applicable law or agreed to in writing, software
> + * distributed under the License is distributed on an "AS IS" BASIS,
> + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
> + * See the License for the specific language governing permissions and
> + * limitations under the License.
> + */
> +
> +#include <config.h>
> +
> +#include <getopt.h>
> +#include <stdlib.h>
> +#include <stdio.h>
> +
> +/* OVS includes */
> +#include "include/openvswitch/hmap.h"
> +#include "lib/bitmap.h"
> +#include "lib/socket-util.h"
> +#include "lib/uuidset.h"
> +#include "openvswitch/util.h"
> +#include "openvswitch/vlog.h"
> +#include "stopwatch.h"
> +
> +/* OVN includes */
> +#include "en-lb-data.h"
> +#include "en-lr-lb-nat-data.h"
> +#include "en-lr-nat.h"
> +#include "lib/inc-proc-eng.h"
> +#include "lib/lb.h"
> +#include "lib/ovn-nb-idl.h"
> +#include "lib/ovn-sb-idl.h"
> +#include "lib/ovn-util.h"
> +#include "lib/stopwatch-names.h"
> +#include "northd.h"
> +
> +VLOG_DEFINE_THIS_MODULE(en_lr_lb_nat_data);
> +
> +/* Static function declarations. */
> +static void lr_lb_nat_data_table_init(struct lr_lb_nat_data_table *);
> +static void lr_lb_nat_data_table_clear(struct lr_lb_nat_data_table *);
> +static void lr_lb_nat_data_table_destroy(struct lr_lb_nat_data_table *);
> +static struct lr_lb_nat_data_record *lr_lb_nat_data_table_find_(
> +    const struct lr_lb_nat_data_table *, const struct nbrec_logical_router *);
> +static struct lr_lb_nat_data_record *lr_lb_nat_data_table_find_by_index_(
> +    const struct lr_lb_nat_data_table *table, size_t od_index);
> +
> +static void lr_lb_nat_data_table_build(struct lr_lb_nat_data_table *,
> +                                   const struct lr_nat_table *,
> +                                   const struct ovn_datapaths *lr_datapaths,
> +                                   const struct hmap *lb_datapaths_map,
> +                                   const struct hmap *lbgrp_datapaths_map);
> +
> +static struct lr_lb_nat_data_input lr_lb_nat_data_get_input_data(
> +    struct engine_node *);
> +
> +static struct lr_lb_nat_data_record *lr_lb_nat_data_record_create(
> +    struct lr_lb_nat_data_table *, const struct lr_nat_record *,
> +    const struct hmap *lb_datapaths_map,
> +    const struct hmap *lbgrp_datapaths_map);
> +static void lr_lb_nat_data_record_destroy(struct lr_lb_nat_data_record *);
> +static void lr_lb_nat_data_record_init(
> +    struct lr_lb_nat_data_record *,
> +    const struct hmap *lb_datapaths_map,
> +    const struct hmap *lbgrp_datapaths_map);
> +
> +static void build_lrouter_lb_reachable_ips(struct lr_lb_nat_data_record *,
> +                                           const struct ovn_northd_lb *);
> +static void add_neigh_ips_to_lrouter(struct lr_lb_nat_data_record *,
> +                                     enum lb_neighbor_responder_mode,
> +                                     const struct sset *lb_ips_v4,
> +                                     const struct sset *lb_ips_v6);
> +static void remove_lrouter_lb_reachable_ips(struct lr_lb_nat_data_record *,
> +                                            enum lb_neighbor_responder_mode,
> +                                            const struct sset *lb_ips_v4,
> +                                            const struct sset *lb_ips_v6);
> +static void lr_lb_nat_data_build_vip_nats(struct lr_lb_nat_data_record *);
> +
> +/* 'lr_lb_nat_data' engine node manages the NB logical router LB data.
> + */
> +void *
> +en_lr_lb_nat_data_init(struct engine_node *node OVS_UNUSED,
> +               struct engine_arg *arg OVS_UNUSED)
> +{
> +    struct ed_type_lr_lb_nat_data *data = xzalloc(sizeof *data);
> +    lr_lb_nat_data_table_init(&data->lr_lbnats);
> +    hmapx_init(&data->tracked_data.crupdated);
> +    hmapx_init(&data->tracked_data.deleted);
> +    return data;
> +}
> +
> +void
> +en_lr_lb_nat_data_cleanup(void *data_)
> +{
> +    struct ed_type_lr_lb_nat_data *data =
> +        (struct ed_type_lr_lb_nat_data *) data_;
> +    lr_lb_nat_data_table_destroy(&data->lr_lbnats);
> +    hmapx_destroy(&data->tracked_data.crupdated);
> +    hmapx_destroy(&data->tracked_data.deleted);
> +}
> +
> +void
> +en_lr_lb_nat_data_clear_tracked_data(void *data_)
> +{
> +    struct ed_type_lr_lb_nat_data *data =
> +        (struct ed_type_lr_lb_nat_data *) data_;
> +
> +    struct hmapx_node *hmapx_node;
> +    HMAPX_FOR_EACH_SAFE (hmapx_node, &data->tracked_data.deleted) {
> +        lr_lb_nat_data_record_destroy(hmapx_node->data);
> +        hmapx_delete(&data->tracked_data.deleted, hmapx_node);
> +    }
> +
> +    hmapx_clear(&data->tracked_data.crupdated);
> +    data->tracked = false;
> +}
> +
> +void
> +en_lr_lb_nat_data_run(struct engine_node *node, void *data_)
> +{
> +    struct lr_lb_nat_data_input input_data =
> +        lr_lb_nat_data_get_input_data(node);
> +    struct ed_type_lr_lb_nat_data *data = data_;
> +
> +    stopwatch_start(LR_LB_NAT_DATA_RUN_STOPWATCH_NAME, time_msec());
> +
> +    lr_lb_nat_data_table_clear(&data->lr_lbnats);
> +    lr_lb_nat_data_table_build(&data->lr_lbnats, input_data.lr_nats,
> +                               input_data.lr_datapaths,
> +                               input_data.lb_datapaths_map,
> +                               input_data.lbgrp_datapaths_map);
> +
> +    stopwatch_stop(LR_LB_NAT_DATA_RUN_STOPWATCH_NAME, time_msec());
> +    engine_set_node_state(node, EN_UPDATED);
> +}
> +
> +bool
> +lr_lb_nat_data_northd_handler(struct engine_node *node, void *data OVS_UNUSED)
> +{
> +    struct northd_data *northd_data = engine_get_input_data("northd", node);
> +    if (!northd_data->change_tracked) {
> +        return false;
> +    }
> +
> +    return true;
> +}
> +
> +bool
> +lr_lb_nat_data_lb_data_handler(struct engine_node *node, void *data_)
> +{
> +    struct ed_type_lb_data *lb_data = engine_get_input_data("lb_data", node);
> +    if (!lb_data->tracked) {
> +        return false;
> +    }
> +
> +    struct ed_type_lr_lb_nat_data *data =
> +        (struct ed_type_lr_lb_nat_data *) data_;
> +    struct lr_lb_nat_data_input input_data =
> +        lr_lb_nat_data_get_input_data(node);
> +    struct lr_lb_nat_data_record *lr_lbnat_rec;
> +    size_t index;
> +
> +    const struct tracked_lb_data *trk_lb_data = &lb_data->tracked_lb_data;
> +    const struct ovn_lb_group_datapaths *lbgrp_dps;
> +    const struct crupdated_lbgrp *crupdated_lbgrp;
> +    const struct crupdated_od_lb_data *codlb;
> +    const struct ovn_lb_datapaths *lb_dps;
> +    const struct crupdated_lb *clb;
> +    const struct ovn_northd_lb *lb;
> +    const struct ovn_datapath *od;
> +
> +    LIST_FOR_EACH (codlb, list_node, &trk_lb_data->crupdated_lr_lbs) {
> +        od = ovn_datapath_find(&input_data.lr_datapaths->datapaths,
> +                               &codlb->od_uuid);
> +        ovs_assert(od);
> +
> +        lr_lbnat_rec = lr_lb_nat_data_table_find_(&data->lr_lbnats, od->nbr);
> +        if (!lr_lbnat_rec) {
> +            const struct lr_nat_record *lrnat_rec = lr_nat_table_find_by_index(
> +                input_data.lr_nats, od->index);
> +            ovs_assert(lrnat_rec);
> +
> +            lr_lbnat_rec = lr_lb_nat_data_record_create(&data->lr_lbnats,
> +                                            lrnat_rec,
> +                                            input_data.lb_datapaths_map,
> +                                            input_data.lbgrp_datapaths_map);
> +
> +            /* Add the lr_lbnat_rec rec to the tracking data. */
> +            hmapx_add(&data->tracked_data.crupdated, lr_lbnat_rec);
> +            continue;
> +        }
> +
> +        struct uuidset_node *uuidnode;
> +        UUIDSET_FOR_EACH (uuidnode, &codlb->assoc_lbs) {
> +            lb_dps = ovn_lb_datapaths_find(
> +                input_data.lb_datapaths_map, &uuidnode->uuid);
> +            ovs_assert(lb_dps);
> +
> +            /* Add the lb_ips of lb_dps to the od. */
> +            build_lrouter_lb_ips(lr_lbnat_rec->lb_ips, lb_dps->lb);
> +            build_lrouter_lb_reachable_ips(lr_lbnat_rec, lb_dps->lb);
> +        }
> +
> +        UUIDSET_FOR_EACH (uuidnode, &codlb->assoc_lbgrps) {
> +            lbgrp_dps = ovn_lb_group_datapaths_find(
> +                input_data.lbgrp_datapaths_map, &uuidnode->uuid);
> +            ovs_assert(lbgrp_dps);
> +
> +            for (size_t j = 0; j < lbgrp_dps->lb_group->n_lbs; j++) {
> +                const struct uuid *lb_uuid
> +                    = &lbgrp_dps->lb_group->lbs[j]->nlb->header_.uuid;
> +                lb_dps = ovn_lb_datapaths_find(input_data.lb_datapaths_map,
> +                                               lb_uuid);
> +                ovs_assert(lb_dps);
> +
> +                /* Add the lb_ips of lb_dps to the od. */
> +                build_lrouter_lb_ips(lr_lbnat_rec->lb_ips, lb_dps->lb);
> +                build_lrouter_lb_reachable_ips(lr_lbnat_rec, lb_dps->lb);
> +            }
> +        }
> +
> +        /* Add the lr_lbnat_rec rec to the tracking data. */
> +        hmapx_add(&data->tracked_data.crupdated, lr_lbnat_rec);
> +    }
> +
> +    HMAP_FOR_EACH (clb, hmap_node, &trk_lb_data->crupdated_lbs) {
> +        lb = clb->lb;
> +        const struct uuid *lb_uuid = &lb->nlb->header_.uuid;
> +
> +        lb_dps = ovn_lb_datapaths_find(input_data.lb_datapaths_map, lb_uuid);
> +        ovs_assert(lb_dps);
> +
> +        BITMAP_FOR_EACH_1 (index, ods_size(input_data.lr_datapaths),
> +                           lb_dps->nb_lr_map) {
> +            od = input_data.lr_datapaths->array[index];
> +
> +            lr_lbnat_rec = lr_lb_nat_data_table_find_(&data->lr_lbnats,
> +                                                      od->nbr);
> +            ovs_assert(lr_lbnat_rec);
> +
> +            /* Update the od->lb_ips with the deleted and inserted
> +             * vips (if any). */
> +            remove_ips_from_lb_ip_set(lr_lbnat_rec->lb_ips, lb->routable,
> +                                      &clb->deleted_vips_v4,
> +                                      &clb->deleted_vips_v6);
> +            add_ips_to_lb_ip_set(lr_lbnat_rec->lb_ips, lb->routable,
> +                                 &clb->inserted_vips_v4,
> +                                 &clb->inserted_vips_v6);
> +
> +            remove_lrouter_lb_reachable_ips(lr_lbnat_rec, lb->neigh_mode,
> +                                            &clb->deleted_vips_v4,
> +                                            &clb->deleted_vips_v6);
> +            add_neigh_ips_to_lrouter(lr_lbnat_rec, lb->neigh_mode,
> +                                     &clb->inserted_vips_v4,
> +                                     &clb->inserted_vips_v6);
> +
> +            /* Add the lr_lbnat_rec rec to the tracking data. */
> +            hmapx_add(&data->tracked_data.crupdated, lr_lbnat_rec);
> +        }
> +    }
> +
> +    HMAP_FOR_EACH (crupdated_lbgrp, hmap_node,
> +                   &trk_lb_data->crupdated_lbgrps) {
> +        const struct uuid *lb_uuid = &crupdated_lbgrp->lbgrp->uuid;
> +
> +        lbgrp_dps = ovn_lb_group_datapaths_find(input_data.lbgrp_datapaths_map,
> +                                                lb_uuid);
> +        ovs_assert(lbgrp_dps);
> +
> +        struct hmapx_node *hnode;
> +        HMAPX_FOR_EACH (hnode, &crupdated_lbgrp->assoc_lbs) {
> +            lb = hnode->data;
> +            lb_uuid = &lb->nlb->header_.uuid;
> +            lb_dps = ovn_lb_datapaths_find(input_data.lb_datapaths_map,
> +                                           lb_uuid);
> +            ovs_assert(lb_dps);
> +            for (size_t i = 0; i < lbgrp_dps->n_lr; i++) {
> +                od = lbgrp_dps->lr[i];
> +                lr_lbnat_rec = lr_lb_nat_data_table_find_(&data->lr_lbnats,
> +                                                          od->nbr);
> +                ovs_assert(lr_lbnat_rec);
> +                /* Add the lb_ips of lb_dps to the lr lb data. */
> +                build_lrouter_lb_ips(lr_lbnat_rec->lb_ips, lb_dps->lb);
> +                build_lrouter_lb_reachable_ips(lr_lbnat_rec, lb_dps->lb);
> +
> +                /* Add the lr_lbnat_rec rec to the tracking data. */
> +                hmapx_add(&data->tracked_data.crupdated, lr_lbnat_rec);
> +            }
> +        }
> +    }
> +
> +    if (!hmapx_is_empty(&data->tracked_data.crupdated)) {
> +        struct hmapx_node *hmapx_node;
> +        /* For all the modified lr_lb_nat_data records (re)build the
> +         * vip nats. */
> +        HMAPX_FOR_EACH (hmapx_node, &data->tracked_data.crupdated) {
> +            lr_lb_nat_data_build_vip_nats(hmapx_node->data);
> +        }
> +
> +        data->tracked = true;
> +        engine_set_node_state(node, EN_UPDATED);
> +    }
> +
> +    return true;
> +}
> +
> +bool
> +lr_lb_nat_data_lr_nat_handler(struct engine_node *node, void *data_)
> +{
> +    struct ed_type_lr_nat_data *lr_nat_data =
> +        engine_get_input_data("lr_nat", node);
> +
> +    if (!lr_nat_data->tracked
> +        || !hmapx_is_empty(&lr_nat_data->tracked_data.deleted)) {
> +        return false;
> +    }
> +
> +    struct ed_type_lr_lb_nat_data *data =
> +        (struct ed_type_lr_lb_nat_data *) data_;
> +    struct lr_lb_nat_data_input input_data =
> +        lr_lb_nat_data_get_input_data(node);
> +    const struct lr_nat_record *lrnat_rec;
> +    struct lr_lb_nat_data_record *lr_lbnat_rec;
> +    struct hmapx_node *hmapx_node;
> +
> +    HMAPX_FOR_EACH (hmapx_node, &lr_nat_data->tracked_data.crupdated) {
> +        lrnat_rec = hmapx_node->data;
> +        lr_lbnat_rec = lr_lb_nat_data_table_find_(&data->lr_lbnats,
> +                                                  lrnat_rec->od->nbr);
> +        if (!lr_lbnat_rec) {
> +            lr_lbnat_rec = lr_lb_nat_data_record_create(&data->lr_lbnats,
> +                                            lrnat_rec,
> +                                            input_data.lb_datapaths_map,
> +                                            input_data.lbgrp_datapaths_map);
> +        } else {
> +            lr_lb_nat_data_build_vip_nats(lr_lbnat_rec);
> +        }
> +
> +        /* Add the lr_lbnat_rec rec to the tracking data. */
> +        hmapx_add(&data->tracked_data.crupdated, lr_lbnat_rec);
> +    }
> +
> +    if (!hmapx_is_empty(&data->tracked_data.crupdated)) {
> +        data->tracked = true;
> +        engine_set_node_state(node, EN_UPDATED);
> +    }
> +
> +    return true;
> +}
> +
> +const struct lr_lb_nat_data_record *
> +lr_lb_nat_data_table_find_by_index(const struct lr_lb_nat_data_table *table,
> +                                   size_t od_index)
> +{
> +    return lr_lb_nat_data_table_find_by_index_(table, od_index);
> +}
> +
> +/* static functions. */
> +static void
> +lr_lb_nat_data_table_init(struct lr_lb_nat_data_table *table)
> +{
> +    *table = (struct lr_lb_nat_data_table) {
> +        .entries = HMAP_INITIALIZER(&table->entries),
> +    };
> +}
> +
> +static void
> +lr_lb_nat_data_table_destroy(struct lr_lb_nat_data_table *table)
> +{
> +    lr_lb_nat_data_table_clear(table);
> +    hmap_destroy(&table->entries);
> +}
> +
> +static void
> +lr_lb_nat_data_table_clear(struct lr_lb_nat_data_table *table)
> +{
> +    struct lr_lb_nat_data_record *lr_lbnat_rec;
> +    HMAP_FOR_EACH_POP (lr_lbnat_rec, key_node, &table->entries) {
> +        lr_lb_nat_data_record_destroy(lr_lbnat_rec);
> +    }
> +
> +    free(table->array);
> +    table->array = NULL;
> +}
> +
> +static void
> +lr_lb_nat_data_table_build(struct lr_lb_nat_data_table *table,
> +                       const struct lr_nat_table *lr_nats,
> +                       const struct ovn_datapaths *lr_datapaths,
> +                       const struct hmap *lb_datapaths_map,
> +                       const struct hmap *lbgrp_datapaths_map)
> +{
> +    table->array = xrealloc(table->array,
> +                            ods_size(lr_datapaths) * sizeof *table->array);
> +    const struct lr_nat_record *lrnat_rec;
> +    LR_NAT_TABLE_FOR_EACH (lrnat_rec, lr_nats) {
> +        lr_lb_nat_data_record_create(table, lrnat_rec, lb_datapaths_map,
> +                                     lbgrp_datapaths_map);
> +    }
> +}
> +
> +static struct lr_lb_nat_data_record *
> +lr_lb_nat_data_table_find_(const struct lr_lb_nat_data_table *table,
> +                  const struct nbrec_logical_router *nbr)
> +{
> +    struct lr_lb_nat_data_record *lr_lbnat_rec;
> +
> +    HMAP_FOR_EACH_WITH_HASH (lr_lbnat_rec, key_node,
> +                             uuid_hash(&nbr->header_.uuid), &table->entries) {
> +        if (nbr == lr_lbnat_rec->od->nbr) {
> +            return lr_lbnat_rec;
> +        }
> +    }
> +    return NULL;
> +}
> +
> +static struct lr_lb_nat_data_record *
> +lr_lb_nat_data_table_find_by_index_(const struct lr_lb_nat_data_table *table,
> +                                   size_t od_index)
> +{
> +    ovs_assert(od_index <= hmap_count(&table->entries));
> +    return table->array[od_index];
> +}
> +
> +static struct lr_lb_nat_data_record *
> +lr_lb_nat_data_record_create(struct lr_lb_nat_data_table *table,
> +                         const struct lr_nat_record *lrnat_rec,
> +                         const struct hmap *lb_datapaths_map,
> +                         const struct hmap *lbgrp_datapaths_map)
> +{
> +    struct lr_lb_nat_data_record *lr_lbnat_rec = xzalloc(sizeof *lr_lbnat_rec);
> +    lr_lbnat_rec->lrnat_rec = lrnat_rec;
> +    lr_lbnat_rec->od = lrnat_rec->od;
> +    lr_lb_nat_data_record_init(lr_lbnat_rec, lb_datapaths_map,
> +                               lbgrp_datapaths_map);
> +
> +    hmap_insert(&table->entries, &lr_lbnat_rec->key_node,
> +                uuid_hash(&lr_lbnat_rec->od->nbr->header_.uuid));
> +
> +    table->array[lr_lbnat_rec->od->index] = lr_lbnat_rec;
> +    return lr_lbnat_rec;
> +}
> +
> +static void
> +lr_lb_nat_data_record_destroy(struct lr_lb_nat_data_record *lr_lbnat_rec)
> +{
> +    ovn_lb_ip_set_destroy(lr_lbnat_rec->lb_ips);
> +    lr_lbnat_rec->lb_ips = NULL;
> +    sset_destroy(&lr_lbnat_rec->vip_nats);
> +    free(lr_lbnat_rec);
> +}
> +
> +static void
> +lr_lb_nat_data_record_init(struct lr_lb_nat_data_record *lr_lbnat_rec,
> +                           const struct hmap *lb_datapaths_map,
> +                           const struct hmap *lbgrp_datapaths_map)
> +{
> +    const struct nbrec_load_balancer_group *nbrec_lb_group;
> +    const struct ovn_lb_group_datapaths *lb_group_dps;
> +    const struct ovn_lb_datapaths *lb_dps;
> +
> +    /* Checking load balancer groups first, starting from the largest one,
> +     * to more efficiently copy IP sets. */
> +    size_t largest_group = 0;
> +
> +    const struct nbrec_logical_router *nbr = lr_lbnat_rec->od->nbr;
> +    for (size_t i = 1; i < nbr->n_load_balancer_group; i++) {
> +        if (nbr->load_balancer_group[i]->n_load_balancer >
> +                nbr->load_balancer_group[largest_group]->n_load_balancer) {
> +            largest_group = i;
> +        }
> +    }
> +
> +    for (size_t i = 0; i < nbr->n_load_balancer_group; i++) {
> +        size_t idx = (i + largest_group) % nbr->n_load_balancer_group;
> +
> +        nbrec_lb_group = nbr->load_balancer_group[idx];
> +        const struct uuid *lbgrp_uuid = &nbrec_lb_group->header_.uuid;
> +
> +        lb_group_dps =
> +            ovn_lb_group_datapaths_find(lbgrp_datapaths_map,
> +                                        lbgrp_uuid);
> +        ovs_assert(lb_group_dps);
> +
> +        if (!lr_lbnat_rec->lb_ips) {
> +            lr_lbnat_rec->lb_ips =
> +                ovn_lb_ip_set_clone(lb_group_dps->lb_group->lb_ips);
> +        } else {
> +            for (size_t j = 0; j < lb_group_dps->lb_group->n_lbs; j++) {
> +                build_lrouter_lb_ips(lr_lbnat_rec->lb_ips,
> +                                     lb_group_dps->lb_group->lbs[j]);
> +            }
> +        }
> +
> +        for (size_t j = 0; j < lb_group_dps->lb_group->n_lbs; j++) {
> +            build_lrouter_lb_reachable_ips(lr_lbnat_rec,
> +                                           lb_group_dps->lb_group->lbs[j]);
> +        }
> +    }
> +
> +    if (!lr_lbnat_rec->lb_ips) {
> +        lr_lbnat_rec->lb_ips = ovn_lb_ip_set_create();
> +    }
> +
> +    for (size_t i = 0; i < nbr->n_load_balancer; i++) {
> +        const struct uuid *lb_uuid =
> +            &nbr->load_balancer[i]->header_.uuid;
> +        lb_dps = ovn_lb_datapaths_find(lb_datapaths_map, lb_uuid);
> +        ovs_assert(lb_dps);
> +        build_lrouter_lb_ips(lr_lbnat_rec->lb_ips, lb_dps->lb);
> +        build_lrouter_lb_reachable_ips(lr_lbnat_rec, lb_dps->lb);
> +    }
> +
> +    sset_init(&lr_lbnat_rec->vip_nats);
> +
> +    if (!nbr->n_nat) {
> +        lr_lb_nat_data_build_vip_nats(lr_lbnat_rec);
> +    }
> +}
> +
> +static struct lr_lb_nat_data_input
> +lr_lb_nat_data_get_input_data(struct engine_node *node)
> +{
> +    struct northd_data *northd_data = engine_get_input_data("northd", node);
> +    struct ed_type_lr_nat_data *lr_nat_data =
> +        engine_get_input_data("lr_nat", node);
> +
> +    return (struct lr_lb_nat_data_input) {
> +        .lr_datapaths = &northd_data->lr_datapaths,
> +        .lb_datapaths_map = &northd_data->lb_datapaths_map,
> +        .lbgrp_datapaths_map = &northd_data->lb_group_datapaths_map,
> +        .lr_nats = &lr_nat_data->lr_nats,
> +    };
> +}
> +
> +static void
> +build_lrouter_lb_reachable_ips(struct lr_lb_nat_data_record *lr_lbnat_rec,
> +                               const struct ovn_northd_lb *lb)
> +{
> +    add_neigh_ips_to_lrouter(lr_lbnat_rec, lb->neigh_mode, &lb->ips_v4,
> +                             &lb->ips_v6);
> +}
> +
> +static void
> +add_neigh_ips_to_lrouter(struct lr_lb_nat_data_record *lr_lbnat_rec,
> +                         enum lb_neighbor_responder_mode neigh_mode,
> +                         const struct sset *lb_ips_v4,
> +                         const struct sset *lb_ips_v6)
> +{
> +    /* If configured to not reply to any neighbor requests for all VIPs
> +     * return early.
> +     */
> +    if (neigh_mode == LB_NEIGH_RESPOND_NONE) {
> +        return;
> +    }
> +
> +    const char *ip_address;
> +
> +    /* If configured to reply to neighbor requests for all VIPs force them
> +     * all to be considered "reachable".
> +     */
> +    if (neigh_mode == LB_NEIGH_RESPOND_ALL) {
> +        SSET_FOR_EACH (ip_address, lb_ips_v4) {
> +            sset_add(&lr_lbnat_rec->lb_ips->ips_v4_reachable, ip_address);
> +        }
> +        SSET_FOR_EACH (ip_address, lb_ips_v6) {
> +            sset_add(&lr_lbnat_rec->lb_ips->ips_v6_reachable, ip_address);
> +        }
> +
> +        return;
> +    }
> +
> +    /* Otherwise, a VIP is reachable if there's at least one router
> +     * subnet that includes it.
> +     */
> +    ovs_assert(neigh_mode == LB_NEIGH_RESPOND_REACHABLE);
> +
> +    SSET_FOR_EACH (ip_address, lb_ips_v4) {
> +        struct ovn_port *op;
> +        ovs_be32 vip_ip4;
> +        if (ip_parse(ip_address, &vip_ip4)) {
> +            HMAP_FOR_EACH (op, dp_node, &lr_lbnat_rec->od->ports) {
> +                if (lrouter_port_ipv4_reachable(op, vip_ip4)) {
> +                    sset_add(&lr_lbnat_rec->lb_ips->ips_v4_reachable,
> +                             ip_address);
> +                    break;
> +                }
> +            }
> +        }
> +    }
> +
> +    SSET_FOR_EACH (ip_address, lb_ips_v6) {
> +        struct ovn_port *op;
> +        struct in6_addr vip;
> +        if (ipv6_parse(ip_address, &vip)) {
> +            HMAP_FOR_EACH (op, dp_node, &lr_lbnat_rec->od->ports) {
> +                if (lrouter_port_ipv6_reachable(op, &vip)) {
> +                    sset_add(&lr_lbnat_rec->lb_ips->ips_v6_reachable,
> +                             ip_address);
> +                    break;
> +                }
> +            }
> +        }
> +    }
> +}
> +
> +static void
> +remove_lrouter_lb_reachable_ips(struct lr_lb_nat_data_record *lr_lbnat_rec,
> +                                enum lb_neighbor_responder_mode neigh_mode,
> +                                const struct sset *lb_ips_v4,
> +                                const struct sset *lb_ips_v6)
> +{
> +    if (neigh_mode == LB_NEIGH_RESPOND_NONE) {
> +        return;
> +    }
> +
> +    const char *ip_address;
> +    SSET_FOR_EACH (ip_address, lb_ips_v4) {
> +        sset_find_and_delete(&lr_lbnat_rec->lb_ips->ips_v4_reachable,
> +                             ip_address);
> +    }
> +    SSET_FOR_EACH (ip_address, lb_ips_v6) {
> +        sset_find_and_delete(&lr_lbnat_rec->lb_ips->ips_v6_reachable,
> +                             ip_address);
> +    }
> +}
> +
> +static void
> +lr_lb_nat_data_build_vip_nats(struct lr_lb_nat_data_record *lr_lbnat_rec)
> +{
> +    sset_clear(&lr_lbnat_rec->vip_nats);
> +    const char *external_ip;
> +    SSET_FOR_EACH (external_ip, &lr_lbnat_rec->lrnat_rec->external_ips) {
> +        bool is_vip_nat = false;
> +        if (addr_is_ipv6(external_ip)) {
> +            is_vip_nat = sset_contains(&lr_lbnat_rec->lb_ips->ips_v6,
> +                                       external_ip);
> +        } else {
> +            is_vip_nat = sset_contains(&lr_lbnat_rec->lb_ips->ips_v4,
> +                                       external_ip);
> +        }
> +
> +        if (is_vip_nat) {
> +            sset_add(&lr_lbnat_rec->vip_nats, external_ip);
> +        }
> +    }
> +}
> diff --git a/northd/en-lr-lb-nat-data.h b/northd/en-lr-lb-nat-data.h
> new file mode 100644
> index 0000000000..9029aee339
> --- /dev/null
> +++ b/northd/en-lr-lb-nat-data.h
> @@ -0,0 +1,93 @@
> +/*
> + * Copyright (c) 2023, Red Hat, Inc.
> + *
> + * Licensed under the Apache License, Version 2.0 (the "License");
> + * you may not use this file except in compliance with the License.
> + * You may obtain a copy of the License at:
> + *
> + *     http://www.apache.org/licenses/LICENSE-2.0
> + *
> + * Unless required by applicable law or agreed to in writing, software
> + * distributed under the License is distributed on an "AS IS" BASIS,
> + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
> + * See the License for the specific language governing permissions and
> + * limitations under the License.
> + */
> +#ifndef EN_LR_LB_NAT_DATA_H
> +#define EN_LR_LB_NAT_DATA_H 1
> +
> +#include <stdint.h>
> +
> +/* OVS includes. */
> +#include "lib/hmapx.h"
> +#include "openvswitch/hmap.h"
> +#include "sset.h"
> +
> +/* OVN includes. */
> +#include "lib/inc-proc-eng.h"
> +#include "lib/lb.h"
> +#include "lib/ovn-nb-idl.h"
> +#include "lib/ovn-sb-idl.h"
> +#include "lib/ovn-util.h"
> +
> +struct ovn_datapath;
> +struct lr_nat_record;
> +
> +struct lr_lb_nat_data_record {
> +    struct hmap_node key_node; /* Index on 'nbr->header_.uuid'. */
> +
> +    const struct ovn_datapath *od;
> +    const struct lr_nat_record *lrnat_rec;
> +
> +    /* Load Balancer vIPs relevant for this datapath. */
> +    struct ovn_lb_ip_set *lb_ips;
> +
> +    /* sset of vips which are also part of lr nats. */
> +    struct sset vip_nats;
> +};
> +
> +struct lr_lb_nat_data_table {
> +    struct hmap entries;
> +
> +    /* The array index of each element in 'entries'. */
> +    struct lr_lb_nat_data_record **array;
> +};
> +
> +#define LR_LB_NAT_DATA_TABLE_FOR_EACH(LR_LB_NAT_REC, TABLE) \
> +    HMAP_FOR_EACH (LR_LB_NAT_REC, key_node, &(TABLE)->entries)
> +
> +struct lr_lb_nat_data_tracked_data {
> +    /* Created or updated logical router with LB data. */
> +    struct hmapx crupdated; /* Stores 'struct lr_lb_nat_data_record'. */
> +
> +    /* Deleted logical router with LB data. */
> +    struct hmapx deleted; /* Stores 'struct lr_lb_nat_data_record'. */
> +};
> +
> +struct ed_type_lr_lb_nat_data {
> +    struct lr_lb_nat_data_table lr_lbnats;
> +
> +    bool tracked;
> +    struct lr_lb_nat_data_tracked_data tracked_data;

Same comment about 'tracked' as in the previous commit, we can probably
remove it.

Which brings me to the following question, we don't really use
lr_lb_nat_data_tracked_data->deleted anywhere; we never add anything to
it.  Is it on purpose, should we just delete it?  Or is it a bug?

Thanks,
Dumitru

> +};
> +
> +struct lr_lb_nat_data_input {
> +    const struct ovn_datapaths *lr_datapaths;
> +    const struct hmap *lb_datapaths_map;
> +    const struct hmap *lbgrp_datapaths_map;
> +    const struct lr_nat_table *lr_nats;
> +};
> +
> +void *en_lr_lb_nat_data_init(struct engine_node *, struct engine_arg *);
> +void en_lr_lb_nat_data_cleanup(void *data);
> +void en_lr_lb_nat_data_clear_tracked_data(void *data);
> +void en_lr_lb_nat_data_run(struct engine_node *, void *data);
> +
> +bool lr_lb_nat_data_northd_handler(struct engine_node *, void *data);
> +bool lr_lb_nat_data_lr_nat_handler(struct engine_node *, void *data);
> +bool lr_lb_nat_data_lb_data_handler(struct engine_node *, void *data);
> +
> +const struct lr_lb_nat_data_record *lr_lb_nat_data_table_find_by_index(
> +    const struct lr_lb_nat_data_table *, size_t od_index);
> +
> +#endif /* EN_LR_LB_NAT_DATA_H */
> \ No newline at end of file
> diff --git a/northd/en-lr-nat.h b/northd/en-lr-nat.h
> index 01a16a21aa..2e3f285d12 100644
> --- a/northd/en-lr-nat.h
> +++ b/northd/en-lr-nat.h
> @@ -89,6 +89,9 @@ struct lr_nat_table {
>  const struct lr_nat_record * lr_nat_table_find_by_index(
>      const struct lr_nat_table *, size_t od_index);
>  
> +#define LR_NAT_TABLE_FOR_EACH(LR_NAT_REC, TABLE) \
> +    HMAP_FOR_EACH (LR_NAT_REC, key_node, &(TABLE)->entries)
> +
>  /* Incremental processing implementation. */
>  struct lr_nat_input {
>      /* Northbound table references. */
> diff --git a/northd/en-sync-sb.c b/northd/en-sync-sb.c
> index 10ade620e7..7c22949f74 100644
> --- a/northd/en-sync-sb.c
> +++ b/northd/en-sync-sb.c
> @@ -22,6 +22,7 @@
>  #include "openvswitch/util.h"
>  
>  #include "en-lr-nat.h"
> +#include "en-lr-lb-nat-data.h"
>  #include "en-sync-sb.h"
>  #include "lib/inc-proc-eng.h"
>  #include "lib/lb.h"
> @@ -41,7 +42,7 @@ static void sync_addr_sets(struct ovsdb_idl_txn *ovnsb_txn,
>                             const struct nbrec_address_set_table *,
>                             const struct nbrec_port_group_table *,
>                             const struct sbrec_address_set_table *,
> -                           const struct ovn_datapaths *lr_datapaths);
> +                           const struct lr_lb_nat_data_table *);
>  static const struct sbrec_address_set *sb_address_set_lookup_by_name(
>      struct ovsdb_idl_index *, const char *name);
>  static void update_sb_addr_set(struct sorted_array *,
> @@ -87,11 +88,11 @@ en_sync_to_sb_addr_set_run(struct engine_node *node, void *data OVS_UNUSED)
>          EN_OVSDB_GET(engine_get_input("SB_address_set", node));
>  
>      const struct engine_context *eng_ctx = engine_get_context();
> -    struct northd_data *northd_data = engine_get_input_data("northd", node);
> -
> +    const struct ed_type_lr_lb_nat_data *lr_lb_nat_data =
> +        engine_get_input_data("lr_lb_nat_data", node);
>      sync_addr_sets(eng_ctx->ovnsb_idl_txn, nb_address_set_table,
>                     nb_port_group_table, sb_address_set_table,
> -                   &northd_data->lr_datapaths);
> +                   &lr_lb_nat_data->lr_lbnats);
>  
>      engine_set_node_state(node, EN_UPDATED);
>  }
> @@ -288,10 +289,12 @@ en_sync_to_sb_pb_run(struct engine_node *node, void *data OVS_UNUSED)
>  {
>      const struct engine_context *eng_ctx = engine_get_context();
>      struct northd_data *northd_data = engine_get_input_data("northd", node);
> -    struct ed_type_lr_nat_data *lr_nat_data =
> -        engine_get_input_data("lr_nat", node);
> +    struct ed_type_lr_lb_nat_data *lr_lb_nat_data =
> +        engine_get_input_data("lr_lb_nat_data", node);
> +
>      sync_pbs(eng_ctx->ovnsb_idl_txn, &northd_data->ls_ports,
> -             &northd_data->lr_ports, &lr_nat_data->lr_nats);
> +             &northd_data->lr_ports,
> +             &lr_lb_nat_data->lr_lbnats);
>      engine_set_node_state(node, EN_UPDATED);
>  }
>  
> @@ -316,11 +319,12 @@ sync_to_sb_pb_northd_handler(struct engine_node *node, void *data OVS_UNUSED)
>          return false;
>      }
>  
> -    struct ed_type_lr_nat_data *lr_nat_data =
> -        engine_get_input_data("lr_nat", node);
> +    struct ed_type_lr_lb_nat_data *lr_lb_nat_data =
> +        engine_get_input_data("lr_lb_nat_data", node);
>  
>      if (!sync_pbs_for_northd_changed_ovn_ports(
> -            &nd->trk_northd_changes.trk_ovn_ports, &lr_nat_data->lr_nats)) {
> +            &nd->trk_northd_changes.trk_ovn_ports,
> +            &lr_lb_nat_data->lr_lbnats)) {
>          return false;
>      }
>  
> @@ -366,7 +370,7 @@ sync_addr_sets(struct ovsdb_idl_txn *ovnsb_txn,
>                 const struct nbrec_address_set_table *nb_address_set_table,
>                 const struct nbrec_port_group_table *nb_port_group_table,
>                 const struct sbrec_address_set_table *sb_address_set_table,
> -               const struct ovn_datapaths *lr_datapaths)
> +               const struct lr_lb_nat_data_table *lr_lbnats)
>  {
>      struct shash sb_address_sets = SHASH_INITIALIZER(&sb_address_sets);
>  
> @@ -410,16 +414,14 @@ sync_addr_sets(struct ovsdb_idl_txn *ovnsb_txn,
>      }
>  
>      /* Sync router load balancer VIP generated address sets. */
> -    struct ovn_datapath *od;
> -    HMAP_FOR_EACH (od, key_node, &lr_datapaths->datapaths) {
> -        ovs_assert(od->nbr);
> -
> -        if (sset_count(&od->lb_ips->ips_v4_reachable)) {
> -            char *ipv4_addrs_name = lr_lb_address_set_name(od->tunnel_key,
> -                                                           AF_INET);
> +    const struct lr_lb_nat_data_record *lrlb_rec;
> +    LR_LB_NAT_DATA_TABLE_FOR_EACH (lrlb_rec, lr_lbnats) {
> +        if (sset_count(&lrlb_rec->lb_ips->ips_v4_reachable)) {
> +            char *ipv4_addrs_name =
> +                lr_lb_address_set_name(lrlb_rec->od->tunnel_key, AF_INET);
>  
>              struct sorted_array ipv4_addrs_sorted =
> -                    sorted_array_from_sset(&od->lb_ips->ips_v4_reachable);
> +                sorted_array_from_sset(&lrlb_rec->lb_ips->ips_v4_reachable);
>  
>              sync_addr_set(ovnsb_txn, ipv4_addrs_name,
>                            &ipv4_addrs_sorted, &sb_address_sets);
> @@ -427,11 +429,11 @@ sync_addr_sets(struct ovsdb_idl_txn *ovnsb_txn,
>              free(ipv4_addrs_name);
>          }
>  
> -        if (sset_count(&od->lb_ips->ips_v6_reachable)) {
> -            char *ipv6_addrs_name = lr_lb_address_set_name(od->tunnel_key,
> -                                                           AF_INET6);
> -            struct sorted_array ipv6_addrs_sorted =
> -                    sorted_array_from_sset(&od->lb_ips->ips_v6_reachable);
> +        if (sset_count(&lrlb_rec->lb_ips->ips_v6_reachable)) {
> +            char *ipv6_addrs_name =
> +                lr_lb_address_set_name(lrlb_rec->od->tunnel_key, AF_INET6);
> +            struct sorted_array ipv6_addrs_sorted = sorted_array_from_sset(
> +                &lrlb_rec->lb_ips->ips_v6_reachable);
>  
>              sync_addr_set(ovnsb_txn, ipv6_addrs_name,
>                            &ipv6_addrs_sorted, &sb_address_sets);
> diff --git a/northd/inc-proc-northd.c b/northd/inc-proc-northd.c
> index 2bd66b8808..369a151fa3 100644
> --- a/northd/inc-proc-northd.c
> +++ b/northd/inc-proc-northd.c
> @@ -31,6 +31,7 @@
>  #include "openvswitch/vlog.h"
>  #include "inc-proc-northd.h"
>  #include "en-lb-data.h"
> +#include "en-lr-lb-nat-data.h"
>  #include "en-lr-nat.h"
>  #include "en-northd.h"
>  #include "en-lflow.h"
> @@ -148,6 +149,7 @@ static ENGINE_NODE(sync_to_sb_lb, "sync_to_sb_lb");
>  static ENGINE_NODE(sync_to_sb_pb, "sync_to_sb_pb");
>  static ENGINE_NODE_WITH_CLEAR_TRACK_DATA(lb_data, "lb_data");
>  static ENGINE_NODE_WITH_CLEAR_TRACK_DATA(lr_nat, "lr_nat");
> +static ENGINE_NODE_WITH_CLEAR_TRACK_DATA(lr_lb_nat_data, "lr_lb_nat_data");
>  
>  void inc_proc_northd_init(struct ovsdb_idl_loop *nb,
>                            struct ovsdb_idl_loop *sb)
> @@ -196,6 +198,13 @@ void inc_proc_northd_init(struct ovsdb_idl_loop *nb,
>      engine_add_input(&en_lr_nat, &en_nb_logical_router,
>                       lr_nat_logical_router_handler);
>  
> +    engine_add_input(&en_lr_lb_nat_data, &en_northd,
> +                     lr_lb_nat_data_northd_handler);
> +    engine_add_input(&en_lr_lb_nat_data, &en_lr_nat,
> +                     lr_lb_nat_data_lr_nat_handler);
> +    engine_add_input(&en_lr_lb_nat_data, &en_lb_data,
> +                     lr_lb_nat_data_lb_data_handler);
> +
>      engine_add_input(&en_mac_binding_aging, &en_nb_nb_global, NULL);
>      engine_add_input(&en_mac_binding_aging, &en_sb_mac_binding, NULL);
>      engine_add_input(&en_mac_binding_aging, &en_northd, NULL);
> @@ -220,12 +229,14 @@ void inc_proc_northd_init(struct ovsdb_idl_loop *nb,
>      engine_add_input(&en_lflow, &en_northd, lflow_northd_handler);
>      engine_add_input(&en_lflow, &en_port_group, lflow_port_group_handler);
>      engine_add_input(&en_lflow, &en_lr_nat, NULL);
> +    engine_add_input(&en_lflow, &en_lr_lb_nat_data, NULL);
>  
>      engine_add_input(&en_sync_to_sb_addr_set, &en_nb_address_set,
>                       sync_to_sb_addr_set_nb_address_set_handler);
>      engine_add_input(&en_sync_to_sb_addr_set, &en_nb_port_group,
>                       sync_to_sb_addr_set_nb_port_group_handler);
>      engine_add_input(&en_sync_to_sb_addr_set, &en_northd, NULL);
> +    engine_add_input(&en_sync_to_sb_addr_set, &en_lr_lb_nat_data, NULL);
>      engine_add_input(&en_sync_to_sb_addr_set, &en_sb_address_set, NULL);
>  
>      engine_add_input(&en_port_group, &en_nb_port_group,
> @@ -243,7 +254,7 @@ void inc_proc_northd_init(struct ovsdb_idl_loop *nb,
>  
>      engine_add_input(&en_sync_to_sb_pb, &en_northd,
>                       sync_to_sb_pb_northd_handler);
> -    engine_add_input(&en_sync_to_sb_pb, &en_lr_nat, NULL);
> +    engine_add_input(&en_sync_to_sb_pb, &en_lr_lb_nat_data, NULL);
>  
>      /* en_sync_to_sb engine node syncs the SB database tables from
>       * the NB database tables.
> diff --git a/northd/northd.c b/northd/northd.c
> index 44c9c3d729..24df14c0de 100644
> --- a/northd/northd.c
> +++ b/northd/northd.c
> @@ -44,6 +44,7 @@
>  #include "northd.h"
>  #include "en-lb-data.h"
>  #include "en-lr-nat.h"
> +#include "en-lr-lb-nat-data.h"
>  #include "lib/ovn-parallel-hmap.h"
>  #include "ovn/actions.h"
>  #include "ovn/features.h"
> @@ -617,13 +618,6 @@ init_lb_for_datapath(struct ovn_datapath *od)
>      }
>  }
>  
> -static void
> -destroy_lb_for_datapath(struct ovn_datapath *od)
> -{
> -    ovn_lb_ip_set_destroy(od->lb_ips);
> -    od->lb_ips = NULL;
> -}
> -
>  /* A group of logical router datapaths which are connected - either
>   * directly or indirectly.
>   * Each logical router can belong to only one group. */
> @@ -676,7 +670,6 @@ ovn_datapath_destroy(struct hmap *datapaths, struct ovn_datapath *od)
>          destroy_ipam_info(&od->ipam_info);
>          free(od->router_ports);
>          free(od->ls_peers);
> -        destroy_lb_for_datapath(od);
>          free(od->localnet_ports);
>          free(od->l3dgw_ports);
>          destroy_mcast_info_for_datapath(od);
> @@ -1311,121 +1304,6 @@ struct lflow_ref_node {
>      struct ovn_lflow *lflow;
>  };
>  
> -/* A logical switch port or logical router port.
> - *
> - * In steady state, an ovn_port points to a northbound Logical_Switch_Port
> - * record (via 'nbsp') *or* a Logical_Router_Port record (via 'nbrp'), and to a
> - * southbound Port_Binding record (via 'sb').  As the state of the system
> - * changes, join_logical_ports() may determine that there is a new LSP or LRP
> - * that has no corresponding Port_Binding record (in which case build_ports())
> - * will create the missing Port_Binding) or that a Port_Binding record exists
> - * that has no coresponding LSP (in which case build_ports() will delete the
> - * spurious Port_Binding).  Thus, after build_ports() runs, any given ovn_port
> - * will have 'sb' nonnull, and 'nbsp' xor 'nbrp' nonnull.
> - *
> - * Ordinarily there is only one ovn_port that points to a given LSP or LRP (but
> - * distributed gateway ports point a "derived" ovn_port to a duplicate LRP).
> - */
> -struct ovn_port {
> -    /* Port name aka key.
> -     *
> -     * This is ordinarily the same as nbsp->name or nbrp->name and
> -     * sb->logical_port.  (A distributed gateway port creates a "derived"
> -     * ovn_port with key "cr-%s" % nbrp->name.) */
> -    struct hmap_node key_node;  /* Index on 'key'. */
> -    char *key;                  /* nbsp->name, nbrp->name, sb->logical_port. */
> -    char *json_key;             /* 'key', quoted for use in JSON. */
> -
> -    const struct sbrec_port_binding *sb;         /* May be NULL. */
> -
> -    uint32_t tunnel_key;
> -
> -    /* Logical switch port data. */
> -    const struct nbrec_logical_switch_port *nbsp; /* May be NULL. */
> -
> -    struct lport_addresses *lsp_addrs;  /* Logical switch port addresses. */
> -    unsigned int n_lsp_addrs;  /* Total length of lsp_addrs. */
> -    unsigned int n_lsp_non_router_addrs; /* Number of elements from the
> -                                          * beginning of 'lsp_addrs' extracted
> -                                          * directly from LSP 'addresses'. */
> -
> -    struct lport_addresses *ps_addrs;   /* Port security addresses. */
> -    unsigned int n_ps_addrs;
> -
> -    bool lsp_can_be_inc_processed; /* If it can be incrementally processed when
> -                                      the port changes. */
> -
> -    /* Logical router port data. */
> -    const struct nbrec_logical_router_port *nbrp; /* May be NULL. */
> -
> -    struct lport_addresses lrp_networks;
> -
> -    struct ovn_port_routable_addresses routables;
> -
> -    /* Logical port multicast data. */
> -    struct mcast_port_info mcast_info;
> -
> -    /* At most one of l3dgw_port and cr_port can be not NULL. */
> -
> -    /* This is set to a distributed gateway port if and only if this ovn_port
> -     * is "derived" from it. Otherwise this is set to NULL. The derived
> -     * ovn_port represents the instance of distributed gateway port on the
> -     * gateway chassis.*/
> -    struct ovn_port *l3dgw_port;
> -
> -    /* This is set to the "derived" chassis-redirect port of this port if and
> -     * only if this port is a distributed gateway port. Otherwise this is set
> -     * to NULL. */
> -    struct ovn_port *cr_port;
> -
> -    bool has_unknown; /* If the addresses have 'unknown' defined. */
> -
> -    bool has_bfd;
> -
> -    /* The port's peer:
> -     *
> -     *     - A switch port S of type "router" has a router port R as a peer,
> -     *       and R in turn has S has its peer.
> -     *
> -     *     - Two connected logical router ports have each other as peer.
> -     *
> -     *     - Other kinds of ports have no peer. */
> -    struct ovn_port *peer;
> -
> -    struct ovn_datapath *od;
> -
> -    struct ovs_list list;       /* In list of similar records. */
> -
> -    struct hmap_node dp_node;   /* Node in od->ports. */
> -
> -    struct lport_addresses proxy_arp_addrs;
> -
> -    /* Temporarily used for traversing a list (or hmap) of ports. */
> -    bool visited;
> -
> -    /* List of struct lflow_ref_node that points to the lflows generated by
> -     * this ovn_port.
> -     *
> -     * This data is initialized and destroyed by the en_northd node, but
> -     * populated and used only by the en_lflow node. Ideally this data should
> -     * be maintained as part of en_lflow's data (struct lflow_data): a hash
> -     * index from ovn_port key to lflows.  However, it would be less efficient
> -     * and more complex:
> -     *
> -     * 1. It would require an extra search (using the index) to find the
> -     * lflows.
> -     *
> -     * 2. Building the index needs to be thread-safe, using either a global
> -     * lock which is obviously less efficient, or hash-based lock array which
> -     * is more complex.
> -     *
> -     * Adding the list here is more straightforward. The drawback is that we
> -     * need to keep in mind that this data belongs to en_lflow node, so never
> -     * access it from any other nodes.
> -     */
> -    struct ovs_list lflows;
> -};
> -
>  static bool lsp_can_be_inc_processed(const struct nbrec_logical_switch_port *);
>  
>  static bool
> @@ -1450,16 +1328,21 @@ destroy_routable_addresses(struct ovn_port_routable_addresses *ra)
>  }
>  
>  static char **get_nat_addresses(const struct ovn_port *op, size_t *n,
> -                                bool routable_only, bool include_lb_ips);
> +                                bool routable_only, bool include_lb_ips,
> +                                const struct lr_lb_nat_data_record *);
>  
> -static void
> -assign_routable_addresses(struct ovn_port *op)
> +static struct ovn_port_routable_addresses
> +get_op_routable_addresses(struct ovn_port *op,
> +                          const struct lr_lb_nat_data_record *lr_lbnat_rec)
>  {
>      size_t n;
> -    char **nats = get_nat_addresses(op, &n, true, true);
> +    char **nats = get_nat_addresses(op, &n, true, true, lr_lbnat_rec);
>  
>      if (!nats) {
> -        return;
> +        return (struct ovn_port_routable_addresses) {
> +            .laddrs = NULL,
> +            .n_addrs = 0,
> +        };
>      }
>  
>      struct lport_addresses *laddrs = xcalloc(n, sizeof(*laddrs));
> @@ -1475,9 +1358,15 @@ assign_routable_addresses(struct ovn_port *op)
>      }
>      free(nats);
>  
> -    /* Everything seems to have worked out */
> -    op->routables.laddrs = laddrs;
> -    op->routables.n_addrs = n_addrs;
> +    if (!n_addrs) {
> +        free(laddrs);
> +        laddrs = NULL;
> +    }
> +
> +    return (struct ovn_port_routable_addresses) {
> +        .laddrs = laddrs,
> +        .n_addrs = n_addrs,
> +    };
>  }
>  
>  
> @@ -1537,8 +1426,6 @@ ovn_port_destroy_orphan(struct ovn_port *port)
>      }
>      free(port->ps_addrs);
>  
> -    destroy_routable_addresses(&port->routables);
> -
>      destroy_lport_addresses(&port->lrp_networks);
>      destroy_lport_addresses(&port->proxy_arp_addrs);
>      free(port->json_key);
> @@ -2580,9 +2467,7 @@ join_logical_ports(const struct sbrec_port_binding_table *sbrec_pb_table,
>                                                   sizeof *od->l3dgw_ports);
>                  }
>                  od->l3dgw_ports[od->n_l3dgw_ports++] = op;
> -
> -                assign_routable_addresses(op);
> -            }
> +           }
>          }
>      }
>  
> @@ -2679,7 +2564,8 @@ join_logical_ports(const struct sbrec_port_binding_table *sbrec_pb_table,
>   * and must free the returned array when it is no longer needed. */
>  static char **
>  get_nat_addresses(const struct ovn_port *op, size_t *n, bool routable_only,
> -                  bool include_lb_ips)
> +                  bool include_lb_ips,
> +                  const struct lr_lb_nat_data_record *lr_lbnat_rec)
>  {
>      size_t n_nats = 0;
>      struct eth_addr mac;
> @@ -2764,23 +2650,25 @@ get_nat_addresses(const struct ovn_port *op, size_t *n, bool routable_only,
>          }
>      }
>  
> -    if (include_lb_ips) {
> +    if (include_lb_ips && lr_lbnat_rec) {
>          const char *ip_address;
>          if (routable_only) {
> -            SSET_FOR_EACH (ip_address, &op->od->lb_ips->ips_v4_routable) {
> +            SSET_FOR_EACH (ip_address,
> +                           &lr_lbnat_rec->lb_ips->ips_v4_routable) {
>                  ds_put_format(&c_addresses, " %s", ip_address);
>                  central_ip_address = true;
>              }
> -            SSET_FOR_EACH (ip_address, &op->od->lb_ips->ips_v6_routable) {
> +            SSET_FOR_EACH (ip_address,
> +                           &lr_lbnat_rec->lb_ips->ips_v6_routable) {
>                  ds_put_format(&c_addresses, " %s", ip_address);
>                  central_ip_address = true;
>              }
>          } else {
> -            SSET_FOR_EACH (ip_address, &op->od->lb_ips->ips_v4) {
> +            SSET_FOR_EACH (ip_address, &lr_lbnat_rec->lb_ips->ips_v4) {
>                  ds_put_format(&c_addresses, " %s", ip_address);
>                  central_ip_address = true;
>              }
> -            SSET_FOR_EACH (ip_address, &op->od->lb_ips->ips_v6) {
> +            SSET_FOR_EACH (ip_address, &lr_lbnat_rec->lb_ips->ips_v6) {
>                  ds_put_format(&c_addresses, " %s", ip_address);
>                  central_ip_address = true;
>              }
> @@ -3851,21 +3739,8 @@ build_lb_datapaths(const struct hmap *lbs, const struct hmap *lb_groups,
>      HMAP_FOR_EACH (od, key_node, &lr_datapaths->datapaths) {
>          ovs_assert(od->nbr);
>  
> -        /* Checking load balancer groups first, starting from the largest one,
> -         * to more efficiently copy IP sets. */
> -        size_t largest_group = 0;
> -
> -        for (size_t i = 1; i < od->nbr->n_load_balancer_group; i++) {
> -            if (od->nbr->load_balancer_group[i]->n_load_balancer >
> -                od->nbr->load_balancer_group[largest_group]->n_load_balancer) {
> -                largest_group = i;
> -            }
> -        }
> -
>          for (size_t i = 0; i < od->nbr->n_load_balancer_group; i++) {
> -            size_t idx = (i + largest_group) % od->nbr->n_load_balancer_group;
> -
> -            nbrec_lb_group = od->nbr->load_balancer_group[idx];
> +            nbrec_lb_group = od->nbr->load_balancer_group[i];
>              const struct uuid *lb_group_uuid = &nbrec_lb_group->header_.uuid;
>  
>              lb_group_dps =
> @@ -3873,20 +3748,6 @@ build_lb_datapaths(const struct hmap *lbs, const struct hmap *lb_groups,
>                                              lb_group_uuid);
>              ovs_assert(lb_group_dps);
>              ovn_lb_group_datapaths_add_lr(lb_group_dps, od);
> -
> -            if (!od->lb_ips) {
> -                od->lb_ips =
> -                    ovn_lb_ip_set_clone(lb_group_dps->lb_group->lb_ips);
> -            } else {
> -                for (size_t j = 0; j < lb_group_dps->lb_group->n_lbs; j++) {
> -                    build_lrouter_lb_ips(od->lb_ips,
> -                                         lb_group_dps->lb_group->lbs[j]);
> -                }
> -            }
> -        }
> -
> -        if (!od->lb_ips) {
> -            od->lb_ips = ovn_lb_ip_set_create();
>          }
>  
>          for (size_t i = 0; i < od->nbr->n_load_balancer; i++) {
> @@ -3895,7 +3756,6 @@ build_lb_datapaths(const struct hmap *lbs, const struct hmap *lb_groups,
>              lb_dps = ovn_lb_datapaths_find(lb_datapaths_map, lb_uuid);
>              ovs_assert(lb_dps);
>              ovn_lb_datapaths_add_lr(lb_dps, 1, &od);
> -            build_lrouter_lb_ips(od->lb_ips, lb_dps->lb);
>          }
>      }
>  
> @@ -3949,102 +3809,6 @@ build_lb_svcs(
>      }
>  }
>  
> -static bool lrouter_port_ipv4_reachable(const struct ovn_port *op,
> -                                        ovs_be32 addr);
> -static bool lrouter_port_ipv6_reachable(const struct ovn_port *op,
> -                                        const struct in6_addr *addr);
> -
> -static void
> -add_neigh_ips_to_lrouter(struct ovn_datapath *od,
> -                         enum lb_neighbor_responder_mode neigh_mode,
> -                         const struct sset *lb_ips_v4,
> -                         const struct sset *lb_ips_v6)
> -{
> -    /* If configured to not reply to any neighbor requests for all VIPs
> -     * return early.
> -     */
> -    if (neigh_mode == LB_NEIGH_RESPOND_NONE) {
> -        return;
> -    }
> -
> -    const char *ip_address;
> -
> -    /* If configured to reply to neighbor requests for all VIPs force them
> -     * all to be considered "reachable".
> -     */
> -    if (neigh_mode == LB_NEIGH_RESPOND_ALL) {
> -        SSET_FOR_EACH (ip_address, lb_ips_v4) {
> -            sset_add(&od->lb_ips->ips_v4_reachable, ip_address);
> -        }
> -        SSET_FOR_EACH (ip_address, lb_ips_v6) {
> -            sset_add(&od->lb_ips->ips_v6_reachable, ip_address);
> -        }
> -
> -        return;
> -    }
> -
> -    /* Otherwise, a VIP is reachable if there's at least one router
> -     * subnet that includes it.
> -     */
> -    ovs_assert(neigh_mode == LB_NEIGH_RESPOND_REACHABLE);
> -
> -    SSET_FOR_EACH (ip_address, lb_ips_v4) {
> -        struct ovn_port *op;
> -        ovs_be32 vip_ip4;
> -        if (ip_parse(ip_address, &vip_ip4)) {
> -            HMAP_FOR_EACH (op, dp_node, &od->ports) {
> -                if (lrouter_port_ipv4_reachable(op, vip_ip4)) {
> -                    sset_add(&od->lb_ips->ips_v4_reachable,
> -                             ip_address);
> -                    break;
> -                }
> -            }
> -        }
> -    }
> -
> -    SSET_FOR_EACH (ip_address, lb_ips_v6) {
> -        struct ovn_port *op;
> -        struct in6_addr vip;
> -        if (ipv6_parse(ip_address, &vip)) {
> -            HMAP_FOR_EACH (op, dp_node, &od->ports) {
> -                if (lrouter_port_ipv6_reachable(op, &vip)) {
> -                    sset_add(&od->lb_ips->ips_v6_reachable,
> -                             ip_address);
> -                    break;
> -                }
> -            }
> -        }
> -    }
> -}
> -
> -static void
> -remove_lrouter_lb_reachable_ips(struct ovn_datapath *od,
> -                                enum lb_neighbor_responder_mode neigh_mode,
> -                                const struct sset *lb_ips_v4,
> -                                const struct sset *lb_ips_v6)
> -{
> -    if (neigh_mode == LB_NEIGH_RESPOND_NONE) {
> -        return;
> -    }
> -
> -    const char *ip_address;
> -    SSET_FOR_EACH (ip_address, lb_ips_v4) {
> -        sset_find_and_delete(&od->lb_ips->ips_v4_reachable, ip_address);
> -    }
> -    SSET_FOR_EACH (ip_address, lb_ips_v6) {
> -        sset_find_and_delete(&od->lb_ips->ips_v6_reachable, ip_address);
> -    }
> -}
> -
> -static void
> -build_lrouter_lb_reachable_ips(struct ovn_datapath *od,
> -                               const struct ovn_northd_lb *lb)
> -{
> -    add_neigh_ips_to_lrouter(od, lb->neigh_mode, &lb->ips_v4,
> -                             &lb->ips_v6);
> -}
> -
> -
>  static void
>  build_lrouter_lbs_check(const struct ovn_datapaths *lr_datapaths)
>  {
> @@ -4066,43 +3830,6 @@ build_lrouter_lbs_check(const struct ovn_datapaths *lr_datapaths)
>      }
>  }
>  
> -static void
> -build_lrouter_lbs_reachable_ips(struct ovn_datapaths *lr_datapaths,
> -                                struct hmap *lb_dps_map,
> -                                struct hmap *lb_group_dps_map)
> -{
> -    struct ovn_datapath *od;
> -
> -    HMAP_FOR_EACH (od, key_node, &lr_datapaths->datapaths) {
> -        if (!od->nbr) {
> -            continue;
> -        }
> -
> -        for (size_t i = 0; i < od->nbr->n_load_balancer; i++) {
> -            struct ovn_lb_datapaths *lb_dps =
> -                ovn_lb_datapaths_find(lb_dps_map,
> -                                &od->nbr->load_balancer[i]->header_.uuid);
> -            ovs_assert(lb_dps);
> -            build_lrouter_lb_reachable_ips(od, lb_dps->lb);
> -        }
> -
> -        for (size_t i = 0; i < od->nbr->n_load_balancer_group; i++) {
> -            const struct nbrec_load_balancer_group *nbrec_lb_group =
> -                od->nbr->load_balancer_group[i];
> -            struct ovn_lb_group_datapaths *lb_group_dps;
> -
> -            lb_group_dps =
> -                ovn_lb_group_datapaths_find(lb_group_dps_map,
> -                                            &nbrec_lb_group->header_.uuid);
> -             ovs_assert(lb_group_dps);
> -            for (size_t j = 0; j < lb_group_dps->lb_group->n_lbs; j++) {
> -                build_lrouter_lb_reachable_ips(od,
> -                                               lb_group_dps->lb_group->lbs[j]);
> -            }
> -        }
> -    }
> -}
> -
>  static void
>  build_lswitch_lbs_from_lrouter(struct ovn_datapaths *lr_datapaths,
>                                 struct hmap *lb_dps_map,
> @@ -4166,8 +3893,6 @@ build_lb_port_related_data(
>      struct hmap *svc_monitor_map)
>  {
>      build_lrouter_lbs_check(lr_datapaths);
> -    build_lrouter_lbs_reachable_ips(lr_datapaths, lb_dps_map,
> -                                    lb_group_dps_map);
>      build_lb_svcs(ovnsb_txn, sbrec_service_monitor_table, ls_ports, lb_dps_map,
>                    svc_monitor_lsps, svc_monitor_map);
>      build_lswitch_lbs_from_lrouter(lr_datapaths, lb_dps_map, lb_group_dps_map);
> @@ -4533,7 +4258,8 @@ check_sb_lb_duplicates(const struct sbrec_load_balancer_table *table)
>   * Caller should make sure that the OVN SB IDL txn is not NULL.  Presently it
>   * only syncs the nat column of port binding corresponding to the 'op->nbsp' */
>  static void
> -sync_pb_for_lsp(struct ovn_port *op)
> +sync_pb_for_lsp(struct ovn_port *op,
> +                const struct lr_lb_nat_data_table *lr_lbnats)
>  {
>      ovs_assert(op->nbsp);
>  
> @@ -4552,10 +4278,17 @@ sync_pb_for_lsp(struct ovn_port *op)
>          if (nat_addresses && !strcmp(nat_addresses, "router")) {
>              if (op->peer && op->peer->od
>                  && (chassis || op->peer->od->n_l3dgw_ports)) {
> -                bool exclude_lb_vips = smap_get_bool(&op->nbsp->options,
> +                bool include_lb_vips = !smap_get_bool(&op->nbsp->options,
>                          "exclude-lb-vips-from-garp", false);
> +
> +                const struct lr_lb_nat_data_record *lr_lbnat_rec = NULL;
> +
> +                if (include_lb_vips) {
> +                    lr_lbnat_rec = lr_lb_nat_data_table_find_by_index(
> +                        lr_lbnats, op->peer->od->index);
> +                }
>                  nats = get_nat_addresses(op->peer, &n_nats, false,
> -                                            !exclude_lb_vips);
> +                                         include_lb_vips, lr_lbnat_rec);
>              }
>          } else if (nat_addresses && (chassis || l3dgw_ports)) {
>              struct lport_addresses laddrs;
> @@ -4662,7 +4395,8 @@ sync_pb_for_lsp(struct ovn_port *op)
>   * Caller should make sure that the OVN SB IDL txn is not NULL.  Presently it
>   * only sets the port binding options column for the router ports */
>  static void
> -sync_pb_for_lrp(struct ovn_port *op, const struct lr_nat_table *lr_nats)
> +sync_pb_for_lrp(struct ovn_port *op,
> +                const struct lr_lb_nat_data_table *lr_lbnats)
>  {
>      ovs_assert(op->nbrp);
>  
> @@ -4671,14 +4405,14 @@ sync_pb_for_lrp(struct ovn_port *op, const struct lr_nat_table *lr_nats)
>  
>      const char *chassis_name = smap_get(&op->od->nbr->options, "chassis");
>      if (is_cr_port(op)) {
> -        const struct lr_nat_record *lrnat_rec =
> -            lr_nat_table_find_by_index(lr_nats, op->od->index);
> -        ovs_assert(lrnat_rec);
> +        const struct lr_lb_nat_data_record *lr_lbnat_rec =
> +            lr_lb_nat_data_table_find_by_index(lr_lbnats, op->od->index);
> +        ovs_assert(lr_lbnat_rec);
>  
>          smap_add(&new, "distributed-port", op->nbrp->name);
>  
>          bool always_redirect =
> -            !lrnat_rec->has_distributed_nat &&
> +            !lr_lbnat_rec->lrnat_rec->has_distributed_nat &&
>              !l3dgw_port_has_associated_vtep_lports(op->l3dgw_port);
>  
>          const char *redirect_type = smap_get(&op->nbrp->options,
> @@ -4729,17 +4463,18 @@ static void ovn_update_ipv6_opt_for_op(struct ovn_port *op);
>   * the logical switch ports. */
>  void
>  sync_pbs(struct ovsdb_idl_txn *ovnsb_idl_txn, struct hmap *ls_ports,
> -         struct hmap *lr_ports, const struct lr_nat_table *lr_nats)
> +         struct hmap *lr_ports,
> +         const struct lr_lb_nat_data_table *lr_lbnats)
>  {
>      ovs_assert(ovnsb_idl_txn);
>  
>      struct ovn_port *op;
>      HMAP_FOR_EACH (op, key_node, ls_ports) {
> -        sync_pb_for_lsp(op);
> +        sync_pb_for_lsp(op, lr_lbnats);
>      }
>  
>      HMAP_FOR_EACH (op, key_node, lr_ports) {
> -        sync_pb_for_lrp(op, lr_nats);
> +        sync_pb_for_lrp(op, lr_lbnats);
>      }
>  
>      ovn_update_ipv6_options(lr_ports);
> @@ -4748,17 +4483,18 @@ sync_pbs(struct ovsdb_idl_txn *ovnsb_idl_txn, struct hmap *ls_ports,
>  /* Sync the SB Port bindings for the added and updated logical switch ports
>   * of the tracked northd engine data. */
>  bool
> -sync_pbs_for_northd_changed_ovn_ports(struct tracked_ovn_ports *trk_ovn_ports,
> -                                      const struct lr_nat_table *lr_nats)
> +sync_pbs_for_northd_changed_ovn_ports(
> +    struct tracked_ovn_ports *trk_ovn_ports,
> +    const struct lr_lb_nat_data_table *lr_lbnats)
>  {
>      struct hmapx_node *hmapx_node;
>      struct ovn_port *op;
>      HMAPX_FOR_EACH (hmapx_node, &trk_ovn_ports->created) {
>          op = hmapx_node->data;
>          if (op->nbsp) {
> -            sync_pb_for_lsp(op);
> +            sync_pb_for_lsp(op, lr_lbnats);
>          } else {
> -            sync_pb_for_lrp(op, lr_nats);
> +            sync_pb_for_lrp(op, lr_lbnats);
>              ovn_update_ipv6_opt_for_op(op);
>          }
>      }
> @@ -4766,9 +4502,9 @@ sync_pbs_for_northd_changed_ovn_ports(struct tracked_ovn_ports *trk_ovn_ports,
>      HMAPX_FOR_EACH (hmapx_node, &trk_ovn_ports->updated) {
>          op = hmapx_node->data;
>          if (op->nbsp) {
> -            sync_pb_for_lsp(op);
> +            sync_pb_for_lsp(op, lr_lbnats);
>          } else {
> -            sync_pb_for_lrp(op, lr_nats);
> +            sync_pb_for_lrp(op, lr_lbnats);
>              ovn_update_ipv6_opt_for_op(op);
>          }
>      }
> @@ -5475,20 +5211,24 @@ fail:
>  }
>  
>  /* Returns true if the logical router has changes which can be
> - * incrementally handled.
> + * incrementally handled or the changes can be ignored.
>   * Presently supports i-p for the below changes:
>   *    - load balancers and load balancer groups.
> + *
> + * Presently below changes are ignored:
> + *    - router NAT changes - as the engine node lr-nat handles it.
>   */
>  static bool
> -lr_changes_can_be_handled(
> +lr_changes_can_be_handled_or_ignored(
>      const struct nbrec_logical_router *lr)
>  {
>      /* Check if the columns are changed in this row. */
>      enum nbrec_logical_router_column_id col;
>      for (col = 0; col < NBREC_LOGICAL_ROUTER_N_COLUMNS; col++) {
>          if (nbrec_logical_router_is_updated(lr, col)) {
> -            if (col == NBREC_LOGICAL_ROUTER_COL_LOAD_BALANCER ||
> -                col == NBREC_LOGICAL_ROUTER_COL_LOAD_BALANCER_GROUP) {
> +            if (col == NBREC_LOGICAL_ROUTER_COL_LOAD_BALANCER
> +                || col == NBREC_LOGICAL_ROUTER_COL_LOAD_BALANCER_GROUP
> +                || col == NBREC_LOGICAL_ROUTER_COL_NAT) {
>                  continue;
>              }
>              return false;
> @@ -5507,12 +5247,6 @@ lr_changes_can_be_handled(
>                                  OVSDB_IDL_CHANGE_MODIFY) > 0) {
>          return false;
>      }
> -    for (size_t i = 0; i < lr->n_nat; i++) {
> -        if (nbrec_nat_row_get_seqno(lr->nat[i],
> -                                OVSDB_IDL_CHANGE_MODIFY) > 0) {
> -            return false;
> -        }
> -    }
>      for (size_t i = 0; i < lr->n_policies; i++) {
>          if (nbrec_logical_router_policy_row_get_seqno(lr->policies[i],
>                                  OVSDB_IDL_CHANGE_MODIFY) > 0) {
> @@ -5528,14 +5262,15 @@ lr_changes_can_be_handled(
>      return true;
>  }
>  
> -/* Return true if changes are handled incrementally, false otherwise.
> +/* Return true if changes are handled incrementally or can be safely
> + * ignored (because those changes are handled by other engine nodes),
> + * false otherwise.
>   * When there are any changes, try to track what's exactly changed and set
>   * northd_data->change_tracked accordingly: change tracked - true, otherwise,
>   * false.
>   * Note: Changes to load balancer and load balancer groups associated with
>   * the logical routers are handled separately in the lb_data change
> - * handlers (northd_handle_lb_data_changes_pre_od and
> - * northd_handle_lb_data_changes_post_od).
> + * handler (northd_handle_lb_data_changes).
>   * */
>  bool
>  northd_handle_lr_changes(const struct northd_input *ni,
> @@ -5550,9 +5285,11 @@ northd_handle_lr_changes(const struct northd_input *ni,
>              goto fail;
>          }
>  
> -        /* Presently only able to handle load balancer and
> -         * load balancer group changes. */
> -        if (!lr_changes_can_be_handled(changed_lr)) {
> +        /* Presently
> +         *   - only able to handle load balancer and load balancer group
> +               changes.
> +         *   - and ignore NAT changes */
> +        if (!lr_changes_can_be_handled_or_ignored(changed_lr)) {
>              goto fail;
>          }
>      }
> @@ -5804,10 +5541,6 @@ northd_handle_lb_data_changes(struct tracked_lb_data *trk_lb_data,
>              ovs_assert(lb_dps);
>              ovn_lb_datapaths_add_lr(lb_dps, 1, &od);
>  
> -            /* Add the lb_ips of lb_dps to the od. */
> -            build_lrouter_lb_ips(od->lb_ips, lb_dps->lb);
> -            build_lrouter_lb_reachable_ips(od, lb_dps->lb);
> -
>              /* Add the lb to the northd tracked data. */
>              hmapx_add(&nd_changes->trk_lbs.crupdated, lb_dps);
>          }
> @@ -5826,10 +5559,6 @@ northd_handle_lb_data_changes(struct tracked_lb_data *trk_lb_data,
>                  ovs_assert(lb_dps);
>                  ovn_lb_datapaths_add_lr(lb_dps, 1, &od);
>  
> -                /* Add the lb_ips of lb_dps to the od. */
> -                build_lrouter_lb_ips(od->lb_ips, lb_dps->lb);
> -                build_lrouter_lb_reachable_ips(od, lb_dps->lb);
> -
>                  /* Add the lb to the northd tracked data. */
>                  hmapx_add(&nd_changes->trk_lbs.crupdated, lb_dps);
>              }
> @@ -5865,22 +5594,6 @@ northd_handle_lb_data_changes(struct tracked_lb_data *trk_lb_data,
>              /* Re-evaluate 'od->has_lb_vip' */
>              init_lb_for_datapath(od);
>  
> -            /* Update the od->lb_ips with the deleted and inserted
> -             * vips (if any). */
> -            remove_ips_from_lb_ip_set(od->lb_ips, lb->routable,
> -                                      &clb->deleted_vips_v4,
> -                                      &clb->deleted_vips_v6);
> -            add_ips_to_lb_ip_set(od->lb_ips, lb->routable,
> -                                 &clb->inserted_vips_v4,
> -                                 &clb->inserted_vips_v6);
> -
> -            remove_lrouter_lb_reachable_ips(od, lb->neigh_mode,
> -                                            &clb->deleted_vips_v4,
> -                                            &clb->deleted_vips_v6);
> -            add_neigh_ips_to_lrouter(od, lb->neigh_mode,
> -                                     &clb->inserted_vips_v4,
> -                                     &clb->inserted_vips_v6);
> -
>              /* Add the lr datapath to the northd tracked data. */
>              hmapx_add(&nd_changes->lr_with_changed_lbs.crupdated, od);
>          }
> @@ -5908,9 +5621,6 @@ northd_handle_lb_data_changes(struct tracked_lb_data *trk_lb_data,
>                  /* Re-evaluate 'od->has_lb_vip' */
>                  init_lb_for_datapath(od);
>  
> -                /* Add the lb_ips of lb_dps to the od. */
> -                build_lrouter_lb_ips(od->lb_ips, lb_dps->lb);
> -
>                  /* Add the lr datapath to the northd tracked data. */
>                  hmapx_add(&nd_changes->lr_with_changed_lbs.crupdated, od);
>              }
> @@ -9202,7 +8912,7 @@ arp_nd_ns_match(const char *ips, int addr_family, struct ds *match)
>  /* Returns 'true' if the IPv4 'addr' is on the same subnet with one of the
>   * IPs configured on the router port.
>   */
> -static bool
> +bool
>  lrouter_port_ipv4_reachable(const struct ovn_port *op, ovs_be32 addr)
>  {
>      for (size_t i = 0; i < op->lrp_networks.n_ipv4_addrs; i++) {
> @@ -9218,7 +8928,7 @@ lrouter_port_ipv4_reachable(const struct ovn_port *op, ovs_be32 addr)
>  /* Returns 'true' if the IPv6 'addr' is on the same subnet with one of the
>   * IPs configured on the router port.
>   */
> -static bool
> +bool
>  lrouter_port_ipv6_reachable(const struct ovn_port *op,
>                              const struct in6_addr *addr)
>  {
> @@ -9284,6 +8994,7 @@ build_lswitch_rport_arp_req_flows(struct ovn_port *op,
>                                    struct ovn_datapath *sw_od,
>                                    struct ovn_port *sw_op,
>                                    const struct lr_nat_table *lr_nats,
> +                                  const struct lr_lb_nat_data_table *lr_lbnats,
>                                    struct hmap *lflows,
>                                    const struct ovsdb_idl_row *stage_hint)
>  {
> @@ -9299,32 +9010,38 @@ build_lswitch_rport_arp_req_flows(struct ovn_port *op,
>       * router port.
>       * Priority: 80.
>       */
> -
> -    const char *ip_addr;
> -    SSET_FOR_EACH (ip_addr, &op->od->lb_ips->ips_v4_reachable) {
> -        ovs_be32 ipv4_addr;
> -
> -        /* Check if the ovn port has a network configured on which we could
> -         * expect ARP requests for the LB VIP.
> -         */
> -        if (ip_parse(ip_addr, &ipv4_addr) &&
> -            lrouter_port_ipv4_reachable(op, ipv4_addr)) {
> -            build_lswitch_rport_arp_req_flow(
> -                ip_addr, AF_INET, sw_op, sw_od, 80, lflows,
> -                stage_hint);
> +    const struct lr_lb_nat_data_record *lr_lbnat_rec = NULL;
> +    if (op->od->nbr->n_load_balancer || op->od->nbr->n_load_balancer_group) {
> +        lr_lbnat_rec = lr_lb_nat_data_table_find_by_index(lr_lbnats,
> +                                                          op->od->index);
> +        ovs_assert(lr_lbnat_rec);
> +
> +        const char *ip_addr;
> +        SSET_FOR_EACH (ip_addr, &lr_lbnat_rec->lb_ips->ips_v4_reachable) {
> +            ovs_be32 ipv4_addr;
> +
> +            /* Check if the ovn port has a network configured on which we could
> +            * expect ARP requests for the LB VIP.
> +            */
> +            if (ip_parse(ip_addr, &ipv4_addr) &&
> +                lrouter_port_ipv4_reachable(op, ipv4_addr)) {
> +                build_lswitch_rport_arp_req_flow(
> +                    ip_addr, AF_INET, sw_op, sw_od, 80, lflows,
> +                    stage_hint);
> +            }
>          }
> -    }
> -    SSET_FOR_EACH (ip_addr, &op->od->lb_ips->ips_v6_reachable) {
> -        struct in6_addr ipv6_addr;
> +        SSET_FOR_EACH (ip_addr, &lr_lbnat_rec->lb_ips->ips_v6_reachable) {
> +            struct in6_addr ipv6_addr;
>  
> -        /* Check if the ovn port has a network configured on which we could
> -         * expect NS requests for the LB VIP.
> -         */
> -        if (ipv6_parse(ip_addr, &ipv6_addr) &&
> -            lrouter_port_ipv6_reachable(op, &ipv6_addr)) {
> -            build_lswitch_rport_arp_req_flow(
> -                ip_addr, AF_INET6, sw_op, sw_od, 80, lflows,
> -                stage_hint);
> +            /* Check if the ovn port has a network configured on which we could
> +            * expect NS requests for the LB VIP.
> +            */
> +            if (ipv6_parse(ip_addr, &ipv6_addr) &&
> +                lrouter_port_ipv6_reachable(op, &ipv6_addr)) {
> +                build_lswitch_rport_arp_req_flow(
> +                    ip_addr, AF_INET6, sw_op, sw_od, 80, lflows,
> +                    stage_hint);
> +            }
>          }
>      }
>  
> @@ -9374,13 +9091,15 @@ build_lswitch_rport_arp_req_flows(struct ovn_port *op,
>           * expect ARP requests/NS for the DNAT external_ip.
>           */
>          if (nat_entry_is_v6(nat_entry)) {
> -            if (!sset_contains(&op->od->lb_ips->ips_v6, nat->external_ip)) {
> +            if (!lr_lbnat_rec || !sset_contains(&lr_lbnat_rec->lb_ips->ips_v6,
> +                                            nat->external_ip)) {
>                  build_lswitch_rport_arp_req_flow(
>                      nat->external_ip, AF_INET6, sw_op, sw_od, 80, lflows,
>                      stage_hint);
>              }
>          } else {
> -            if (!sset_contains(&op->od->lb_ips->ips_v4, nat->external_ip)) {
> +            if (!lr_lbnat_rec || !sset_contains(&lr_lbnat_rec->lb_ips->ips_v4,
> +                                            nat->external_ip)) {
>                  build_lswitch_rport_arp_req_flow(
>                      nat->external_ip, AF_INET, sw_op, sw_od, 80, lflows,
>                      stage_hint);
> @@ -10441,6 +10160,7 @@ build_lswitch_ip_mcast_igmp_mld(struct ovn_igmp_group *igmp_group,
>  static void
>  build_lswitch_ip_unicast_lookup(struct ovn_port *op,
>                                  const struct lr_nat_table *lr_nats,
> +                                const struct lr_lb_nat_data_table *lr_lbnats,
>                                  struct hmap *lflows,
>                                  struct ds *actions,
>                                  struct ds *match)
> @@ -10456,7 +10176,8 @@ build_lswitch_ip_unicast_lookup(struct ovn_port *op,
>       */
>      if (lsp_is_router(op->nbsp)) {
>          build_lswitch_rport_arp_req_flows(op->peer, op->od, op, lr_nats,
> -                                          lflows, &op->nbsp->header_);
> +                                          lr_lbnats, lflows,
> +                                          &op->nbsp->header_);
>      }
>  
>      for (size_t i = 0; i < op->nbsp->n_addresses; i++) {
> @@ -12646,6 +12367,7 @@ build_lrouter_port_nat_arp_nd_flow(struct ovn_port *op,
>  static void
>  build_lrouter_drop_own_dest(struct ovn_port *op,
>                              const struct lr_nat_record *lrnat_rec,
> +                            const struct lr_lb_nat_data_record *lr_lbnat_rec,
>                              enum ovn_stage stage,
>                              uint16_t priority, bool drop_snat_ip,
>                              struct hmap *lflows)
> @@ -12658,8 +12380,9 @@ build_lrouter_drop_own_dest(struct ovn_port *op,
>  
>              bool router_ip_in_snat_ips = !!shash_find(&lrnat_rec->snat_ips,
>                                                        ip);
> -            bool router_ip_in_lb_ips =
> -                    !!sset_find(&op->od->lb_ips->ips_v4, ip);
> +            bool router_ip_in_lb_ips = (lr_lbnat_rec &&
> +                                    !!sset_find(&lr_lbnat_rec->lb_ips->ips_v4,
> +                                                ip));
>              bool drop_router_ip = (drop_snat_ip == (router_ip_in_snat_ips ||
>                                                      router_ip_in_lb_ips));
>  
> @@ -12688,8 +12411,9 @@ build_lrouter_drop_own_dest(struct ovn_port *op,
>  
>              bool router_ip_in_snat_ips = !!shash_find(&lrnat_rec->snat_ips,
>                                                        ip);
> -            bool router_ip_in_lb_ips =
> -                    !!sset_find(&op->od->lb_ips->ips_v6, ip);
> +            bool router_ip_in_lb_ips = (lr_lbnat_rec &&
> +                                    !!sset_find(&lr_lbnat_rec->lb_ips->ips_v6,
> +                                                ip));
>              bool drop_router_ip = (drop_snat_ip == (router_ip_in_snat_ips ||
>                                                      router_ip_in_lb_ips));
>  
> @@ -13401,7 +13125,8 @@ build_ip_routing_flows_for_lrp(
>   */
>  static void
>  build_ip_routing_flows_for_router_type_lsp(
> -        struct ovn_port *op, const struct hmap *lr_ports, struct hmap *lflows)
> +        struct ovn_port *op, const struct lr_lb_nat_data_table *lr_lbnats,
> +        const struct hmap *lr_ports, struct hmap *lflows)
>  {
>      ovs_assert(op->nbsp);
>      if (!lsp_is_router(op->nbsp)) {
> @@ -13409,7 +13134,8 @@ build_ip_routing_flows_for_router_type_lsp(
>      }
>  
>      struct ovn_port *peer = ovn_port_get_peer(lr_ports, op);
> -    if (!peer || !peer->nbrp || !peer->lrp_networks.n_ipv4_addrs) {
> +    if (!peer || !peer->nbrp || !peer->lrp_networks.n_ipv4_addrs
> +        || !op->od->n_router_ports) {
>          return;
>      }
>  
> @@ -13420,19 +13146,29 @@ build_ip_routing_flows_for_router_type_lsp(
>              continue;
>          }
>  
> -        struct ovn_port_routable_addresses *ra = &router_port->routables;
> -        for (size_t j = 0; j < ra->n_addrs; j++) {
> -            struct lport_addresses *laddrs = &ra->laddrs[j];
> -            for (size_t k = 0; k < laddrs->n_ipv4_addrs; k++) {
> -                add_route(lflows, peer->od, peer,
> -                          peer->lrp_networks.ipv4_addrs[0].addr_s,
> -                          laddrs->ipv4_addrs[k].network_s,
> -                          laddrs->ipv4_addrs[k].plen, NULL, false, 0,
> -                          &peer->nbrp->header_, false,
> -                          ROUTE_PRIO_OFFSET_CONNECTED);
> +        const struct lr_lb_nat_data_record *lr_lbnat_rec =
> +            lr_lb_nat_data_table_find_by_index(lr_lbnats,
> +                                               router_port->od->index);
> +
> +        if (router_port->nbrp->ha_chassis_group ||
> +                router_port->nbrp->n_gateway_chassis) {
> +            struct ovn_port_routable_addresses ra =
> +                get_op_routable_addresses(router_port, lr_lbnat_rec);
> +            for (size_t j = 0; j < ra.n_addrs; j++) {
> +                struct lport_addresses *laddrs = &ra.laddrs[j];
> +                for (size_t k = 0; k < laddrs->n_ipv4_addrs; k++) {
> +                    add_route(lflows, peer->od, peer,
> +                            peer->lrp_networks.ipv4_addrs[0].addr_s,
> +                            laddrs->ipv4_addrs[k].network_s,
> +                            laddrs->ipv4_addrs[k].plen, NULL, false, 0,
> +                            &peer->nbrp->header_, false,
> +                            ROUTE_PRIO_OFFSET_CONNECTED);
> +                }
>              }
> +            destroy_routable_addresses(&ra);
>          }
>      }
> +
>  }
>  
>  static void
> @@ -13656,33 +13392,36 @@ build_arp_resolve_flows_for_lrouter(
>  
>  static void
>  routable_addresses_to_lflows(struct hmap *lflows, struct ovn_port *router_port,
> -                             struct ovn_port *peer, struct ds *match,
> -                             struct ds *actions)
> +                             struct ovn_port *peer,
> +                             const struct lr_lb_nat_data_record *lr_lbnat_rec,
> +                             struct ds *match, struct ds *actions)
>  {
> -    struct ovn_port_routable_addresses *ra = &router_port->routables;
> -    if (!ra->n_addrs) {
> +    struct ovn_port_routable_addresses ra =
> +        get_op_routable_addresses(router_port, lr_lbnat_rec);
> +    if (!ra.n_addrs) {
>          return;
>      }
>  
> -    for (size_t i = 0; i < ra->n_addrs; i++) {
> +    for (size_t i = 0; i < ra.n_addrs; i++) {
>          ds_clear(match);
>          ds_put_format(match, "outport == %s && "REG_NEXT_HOP_IPV4" == {",
>                        peer->json_key);
>          bool first = true;
> -        for (size_t j = 0; j < ra->laddrs[i].n_ipv4_addrs; j++) {
> +        for (size_t j = 0; j < ra.laddrs[i].n_ipv4_addrs; j++) {
>              if (!first) {
>                  ds_put_cstr(match, ", ");
>              }
> -            ds_put_cstr(match, ra->laddrs[i].ipv4_addrs[j].addr_s);
> +            ds_put_cstr(match, ra.laddrs[i].ipv4_addrs[j].addr_s);
>              first = false;
>          }
>          ds_put_cstr(match, "}");
>  
>          ds_clear(actions);
> -        ds_put_format(actions, "eth.dst = %s; next;", ra->laddrs[i].ea_s);
> +        ds_put_format(actions, "eth.dst = %s; next;", ra.laddrs[i].ea_s);
>          ovn_lflow_add(lflows, peer->od, S_ROUTER_IN_ARP_RESOLVE, 100,
>                        ds_cstr(match), ds_cstr(actions));
>      }
> +    destroy_routable_addresses(&ra);
>  }
>  
>  /* Local router ingress table ARP_RESOLVE: ARP Resolution.
> @@ -13699,6 +13438,7 @@ routable_addresses_to_lflows(struct hmap *lflows, struct ovn_port *router_port,
>  static void
>  build_arp_resolve_flows_for_lrp(
>          struct ovn_port *op, const struct lr_nat_record *lrnat_rec,
> +        const struct lr_lb_nat_data_record *lr_lbnat_rec,
>          struct hmap *lflows, struct ds *match, struct ds *actions)
>  {
>      ovs_assert(op->nbrp);
> @@ -13775,8 +13515,8 @@ build_arp_resolve_flows_for_lrp(
>       *
>       * Priority 2.
>       */
> -    build_lrouter_drop_own_dest(op, lrnat_rec, S_ROUTER_IN_ARP_RESOLVE, 2,
> -                                true, lflows);
> +    build_lrouter_drop_own_dest(op, lrnat_rec, lr_lbnat_rec,
> +                                S_ROUTER_IN_ARP_RESOLVE, 2, true, lflows);
>  }
>  
>  /* This function adds ARP resolve flows related to a LSP. */
> @@ -13784,6 +13524,7 @@ static void
>  build_arp_resolve_flows_for_lsp(
>          struct ovn_port *op, struct hmap *lflows,
>          const struct hmap *lr_ports,
> +        const struct lr_lb_nat_data_table *lr_lbnats,
>          struct ds *match, struct ds *actions)
>  {
>      ovs_assert(op->nbsp);
> @@ -13927,8 +13668,11 @@ build_arp_resolve_flows_for_lsp(
>  
>              if (smap_get(&peer->od->nbr->options, "chassis")
>                  || peer->cr_port) {
> +                const struct lr_lb_nat_data_record *lr_lbnat_rec;
> +                lr_lbnat_rec = lr_lb_nat_data_table_find_by_index(lr_lbnats,
> +                                                    router_port->od->index);
>                  routable_addresses_to_lflows(lflows, router_port, peer,
> -                                             match, actions);
> +                                             lr_lbnat_rec, match, actions);
>              }
>          }
>      }
> @@ -14648,6 +14392,7 @@ static void
>  build_lrouter_ipv4_ip_input(struct ovn_port *op,
>                              struct hmap *lflows,
>                              const struct lr_nat_record *lrnat_rec,
> +                            const struct lr_lb_nat_data_record *lr_lbnat_rec,
>                              struct ds *match, struct ds *actions,
>                              const struct shash *meter_groups)
>  {
> @@ -14772,7 +14517,7 @@ build_lrouter_ipv4_ip_input(struct ovn_port *op,
>                                 &op->nbrp->header_, lflows);
>      }
>  
> -    if (sset_count(&op->od->lb_ips->ips_v4_reachable)) {
> +    if (lr_lbnat_rec && sset_count(&lr_lbnat_rec->lb_ips->ips_v4_reachable)) {
>          ds_clear(match);
>          if (is_l3dgw_port(op)) {
>              ds_put_format(match, "is_chassis_resident(%s)",
> @@ -14788,7 +14533,7 @@ build_lrouter_ipv4_ip_input(struct ovn_port *op,
>          free(lb_ips_v4_as);
>      }
>  
> -    if (sset_count(&op->od->lb_ips->ips_v6_reachable)) {
> +    if (lr_lbnat_rec && sset_count(&lr_lbnat_rec->lb_ips->ips_v6_reachable)) {
>          ds_clear(match);
>  
>          if (is_l3dgw_port(op)) {
> @@ -14890,8 +14635,8 @@ build_lrouter_ipv4_ip_input(struct ovn_port *op,
>       * Priority 60.
>       */
>      if (!lrnat_rec->lb_force_snat_router_ip) {
> -        build_lrouter_drop_own_dest(op, lrnat_rec, S_ROUTER_IN_IP_INPUT, 60,
> -                                    false, lflows);
> +        build_lrouter_drop_own_dest(op, lrnat_rec, lr_lbnat_rec,
> +                                    S_ROUTER_IN_IP_INPUT, 60, false, lflows);
>      }
>      /* ARP / ND handling for external IP addresses.
>       *
> @@ -16030,6 +15775,7 @@ struct lswitch_flow_build_info {
>      const struct hmap *lr_ports;
>      const struct ls_port_group_table *ls_port_groups;
>      const struct lr_nat_table *lr_nats;
> +    const struct lr_lb_nat_data_table *lr_lbnats;
>      struct hmap *lflows;
>      struct hmap *igmp_groups;
>      const struct shash *meter_groups;
> @@ -16113,14 +15859,15 @@ build_lswitch_and_lrouter_iterate_by_lr(struct ovn_datapath *od,
>   * switch port.
>   */
>  static void
> -build_lswitch_and_lrouter_iterate_by_lsp(struct ovn_port *op,
> -                                         const struct hmap *ls_ports,
> -                                         const struct hmap *lr_ports,
> -                                         const struct lr_nat_table *lr_nats,
> -                                         const struct shash *meter_groups,
> -                                         struct ds *match,
> -                                         struct ds *actions,
> -                                         struct hmap *lflows)
> +build_lswitch_and_lrouter_iterate_by_lsp(
> +    struct ovn_port *op, const struct hmap *ls_ports,
> +    const struct hmap *lr_ports,
> +    const struct lr_nat_table *lr_nats,
> +    const struct lr_lb_nat_data_table *lr_lbnats,
> +    const struct shash *meter_groups,
> +    struct ds *match,
> +    struct ds *actions,
> +    struct hmap *lflows)
>  {
>      ovs_assert(op->nbsp);
>      start_collecting_lflows();
> @@ -16133,11 +15880,14 @@ build_lswitch_and_lrouter_iterate_by_lsp(struct ovn_port *op,
>                                               meter_groups, actions, match);
>      build_lswitch_dhcp_options_and_response(op, lflows, meter_groups);
>      build_lswitch_external_port(op, lflows);
> -    build_lswitch_ip_unicast_lookup(op, lr_nats, lflows, actions, match);
> +    build_lswitch_ip_unicast_lookup(op, lr_nats, lr_lbnats, lflows, actions,
> +                                    match);
>  
>      /* Build Logical Router Flows. */
> -    build_ip_routing_flows_for_router_type_lsp(op, lr_ports, lflows);
> -    build_arp_resolve_flows_for_lsp(op, lflows, lr_ports, match, actions);
> +    build_ip_routing_flows_for_router_type_lsp(op, lr_lbnats, lr_ports,
> +                                               lflows);
> +    build_arp_resolve_flows_for_lsp(op, lflows, lr_ports, lr_lbnats,
> +                                    match, actions);
>  
>      link_ovn_port_to_lflows(op, &collected_lflows);
>      end_collecting_lflows();
> @@ -16156,6 +15906,8 @@ build_lswitch_and_lrouter_iterate_by_lrp(struct ovn_port *op,
>          lsi->lr_nats, op->od->index);
>      ovs_assert(lrnet_rec);
>  
> +    const struct lr_lb_nat_data_record *lr_lbnat_rec =
> +        lr_lb_nat_data_table_find_by_index(lsi->lr_lbnats, op->od->index);
>      build_adm_ctrl_flows_for_lrouter_port(op, lsi->lflows, &lsi->match,
>                                            &lsi->actions);
>      build_neigh_learning_flows_for_lrouter_port(op, lsi->lflows, &lsi->match,
> @@ -16163,15 +15915,15 @@ build_lswitch_and_lrouter_iterate_by_lrp(struct ovn_port *op,
>      build_ip_routing_flows_for_lrp(op, lsi->lflows);
>      build_ND_RA_flows_for_lrouter_port(op, lsi->lflows, &lsi->match,
>                                         &lsi->actions, lsi->meter_groups);
> -    build_arp_resolve_flows_for_lrp(op, lrnet_rec, lsi->lflows, &lsi->match,
> -                                    &lsi->actions);
> +    build_arp_resolve_flows_for_lrp(op, lrnet_rec, lr_lbnat_rec, lsi->lflows,
> +                                    &lsi->match, &lsi->actions);
>      build_egress_delivery_flows_for_lrouter_port(op, lsi->lflows, &lsi->match,
>                                                   &lsi->actions);
>      build_dhcpv6_reply_flows_for_lrouter_port(op, lsi->lflows, &lsi->match);
>      build_ipv6_input_flows_for_lrouter_port(op, lsi->lflows,
>                                              &lsi->match, &lsi->actions,
>                                              lsi->meter_groups);
> -    build_lrouter_ipv4_ip_input(op, lsi->lflows, lrnet_rec,
> +    build_lrouter_ipv4_ip_input(op, lsi->lflows, lrnet_rec, lr_lbnat_rec,
>                                  &lsi->match, &lsi->actions, lsi->meter_groups);
>      build_lrouter_force_snat_flows_op(op, lrnet_rec, lsi->lflows, &lsi->match,
>                                        &lsi->actions);
> @@ -16234,6 +15986,7 @@ build_lflows_thread(void *arg)
>                      build_lswitch_and_lrouter_iterate_by_lsp(op, lsi->ls_ports,
>                                                               lsi->lr_ports,
>                                                               lsi->lr_nats,
> +                                                             lsi->lr_lbnats,
>                                                               lsi->meter_groups,
>                                                               &lsi->match,
>                                                               &lsi->actions,
> @@ -16344,6 +16097,7 @@ build_lswitch_and_lrouter_flows(const struct ovn_datapaths *ls_datapaths,
>                                  const struct hmap *lr_ports,
>                                  const struct ls_port_group_table *ls_pgs,
>                                  const struct lr_nat_table *lr_nats,
> +                                const struct lr_lb_nat_data_table *lr_lbnats,
>                                  struct hmap *lflows,
>                                  struct hmap *igmp_groups,
>                                  const struct shash *meter_groups,
> @@ -16374,6 +16128,7 @@ build_lswitch_and_lrouter_flows(const struct ovn_datapaths *ls_datapaths,
>              lsiv[index].lr_ports = lr_ports;
>              lsiv[index].ls_port_groups = ls_pgs;
>              lsiv[index].lr_nats = lr_nats;
> +            lsiv[index].lr_lbnats = lr_lbnats;
>              lsiv[index].igmp_groups = igmp_groups;
>              lsiv[index].meter_groups = meter_groups;
>              lsiv[index].lb_dps_map = lb_dps_map;
> @@ -16409,6 +16164,7 @@ build_lswitch_and_lrouter_flows(const struct ovn_datapaths *ls_datapaths,
>              .lr_ports = lr_ports,
>              .ls_port_groups = ls_pgs,
>              .lr_nats = lr_nats,
> +            .lr_lbnats = lr_lbnats,
>              .lflows = lflows,
>              .igmp_groups = igmp_groups,
>              .meter_groups = meter_groups,
> @@ -16437,6 +16193,7 @@ build_lswitch_and_lrouter_flows(const struct ovn_datapaths *ls_datapaths,
>              build_lswitch_and_lrouter_iterate_by_lsp(op, lsi.ls_ports,
>                                                       lsi.lr_ports,
>                                                       lsi.lr_nats,
> +                                                     lsi.lr_lbnats,
>                                                       lsi.meter_groups,
>                                                       &lsi.match, &lsi.actions,
>                                                       lsi.lflows);
> @@ -16558,6 +16315,7 @@ void build_lflows(struct ovsdb_idl_txn *ovnsb_txn,
>                                      input_data->lr_ports,
>                                      input_data->ls_port_groups,
>                                      input_data->lr_nats,
> +                                    input_data->lr_lbnats,
>                                      lflows,
>                                      &igmp_groups,
>                                      input_data->meter_groups,
> @@ -17038,6 +16796,7 @@ lflow_handle_northd_port_changes(struct ovsdb_idl_txn *ovnsb_txn,
>          build_lswitch_and_lrouter_iterate_by_lsp(op, lflow_input->ls_ports,
>                                                   lflow_input->lr_ports,
>                                                   lflow_input->lr_nats,
> +                                                 lflow_input->lr_lbnats,
>                                                   lflow_input->meter_groups,
>                                                   &match, &actions,
>                                                   lflows);
> @@ -17076,6 +16835,7 @@ lflow_handle_northd_port_changes(struct ovsdb_idl_txn *ovnsb_txn,
>          build_lswitch_and_lrouter_iterate_by_lsp(op, lflow_input->ls_ports,
>                                                      lflow_input->lr_ports,
>                                                      lflow_input->lr_nats,
> +                                                    lflow_input->lr_lbnats,
>                                                      lflow_input->meter_groups,
>                                                      &match, &actions,
>                                                      lflows);
> diff --git a/northd/northd.h b/northd/northd.h
> index 564729ebcc..7c446f5758 100644
> --- a/northd/northd.h
> +++ b/northd/northd.h
> @@ -179,6 +179,7 @@ struct lflow_input {
>      const struct hmap *lr_ports;
>      const struct ls_port_group_table *ls_port_groups;
>      const struct lr_nat_table *lr_nats;
> +    const struct lr_lb_nat_data_table *lr_lbnats;
>      const struct shash *meter_groups;
>      const struct hmap *lb_datapaths_map;
>      const struct hmap *bfd_connections;
> @@ -318,9 +319,6 @@ struct ovn_datapath {
>      /* router datapath has a logical port with redirect-type set to bridged. */
>      bool redirect_bridged;
>  
> -    /* Load Balancer vIPs relevant for this datapath. */
> -    struct ovn_lb_ip_set *lb_ips;
> -
>      struct ovn_port **localnet_ports;
>      size_t n_localnet_ports;
>  
> @@ -337,6 +335,119 @@ struct ovn_datapath {
>  const struct ovn_datapath *ovn_datapath_find(const struct hmap *datapaths,
>                                               const struct uuid *uuid);
>  
> +/* A logical switch port or logical router port.
> + *
> + * In steady state, an ovn_port points to a northbound Logical_Switch_Port
> + * record (via 'nbsp') *or* a Logical_Router_Port record (via 'nbrp'), and to a
> + * southbound Port_Binding record (via 'sb').  As the state of the system
> + * changes, join_logical_ports() may determine that there is a new LSP or LRP
> + * that has no corresponding Port_Binding record (in which case build_ports())
> + * will create the missing Port_Binding) or that a Port_Binding record exists
> + * that has no coresponding LSP (in which case build_ports() will delete the
> + * spurious Port_Binding).  Thus, after build_ports() runs, any given ovn_port
> + * will have 'sb' nonnull, and 'nbsp' xor 'nbrp' nonnull.
> + *
> + * Ordinarily there is only one ovn_port that points to a given LSP or LRP (but
> + * distributed gateway ports point a "derived" ovn_port to a duplicate LRP).
> + */
> +struct ovn_port {
> +    /* Port name aka key.
> +     *
> +     * This is ordinarily the same as nbsp->name or nbrp->name and
> +     * sb->logical_port.  (A distributed gateway port creates a "derived"
> +     * ovn_port with key "cr-%s" % nbrp->name.) */
> +    struct hmap_node key_node;  /* Index on 'key'. */
> +    char *key;                  /* nbsp->name, nbrp->name, sb->logical_port. */
> +    char *json_key;             /* 'key', quoted for use in JSON. */
> +
> +    const struct sbrec_port_binding *sb;         /* May be NULL. */
> +
> +    uint32_t tunnel_key;
> +
> +    /* Logical switch port data. */
> +    const struct nbrec_logical_switch_port *nbsp; /* May be NULL. */
> +
> +    struct lport_addresses *lsp_addrs;  /* Logical switch port addresses. */
> +    unsigned int n_lsp_addrs;  /* Total length of lsp_addrs. */
> +    unsigned int n_lsp_non_router_addrs; /* Number of elements from the
> +                                          * beginning of 'lsp_addrs' extracted
> +                                          * directly from LSP 'addresses'. */
> +
> +    struct lport_addresses *ps_addrs;   /* Port security addresses. */
> +    unsigned int n_ps_addrs;
> +
> +    bool lsp_can_be_inc_processed; /* If it can be incrementally processed when
> +                                      the port changes. */
> +
> +    /* Logical router port data. */
> +    const struct nbrec_logical_router_port *nbrp; /* May be NULL. */
> +
> +    struct lport_addresses lrp_networks;
> +
> +    /* Logical port multicast data. */
> +    struct mcast_port_info mcast_info;
> +
> +    /* At most one of l3dgw_port and cr_port can be not NULL. */
> +
> +    /* This is set to a distributed gateway port if and only if this ovn_port
> +     * is "derived" from it. Otherwise this is set to NULL. The derived
> +     * ovn_port represents the instance of distributed gateway port on the
> +     * gateway chassis.*/
> +    struct ovn_port *l3dgw_port;
> +
> +    /* This is set to the "derived" chassis-redirect port of this port if and
> +     * only if this port is a distributed gateway port. Otherwise this is set
> +     * to NULL. */
> +    struct ovn_port *cr_port;
> +
> +    bool has_unknown; /* If the addresses have 'unknown' defined. */
> +
> +    bool has_bfd;
> +
> +    /* The port's peer:
> +     *
> +     *     - A switch port S of type "router" has a router port R as a peer,
> +     *       and R in turn has S has its peer.
> +     *
> +     *     - Two connected logical router ports have each other as peer.
> +     *
> +     *     - Other kinds of ports have no peer. */
> +    struct ovn_port *peer;
> +
> +    struct ovn_datapath *od;
> +
> +    struct ovs_list list;       /* In list of similar records. */
> +
> +    struct hmap_node dp_node;   /* Node in od->ports. */
> +
> +    struct lport_addresses proxy_arp_addrs;
> +
> +    /* Temporarily used for traversing a list (or hmap) of ports. */
> +    bool visited;
> +
> +    /* List of struct lflow_ref_node that points to the lflows generated by
> +     * this ovn_port.
> +     *
> +     * This data is initialized and destroyed by the en_northd node, but
> +     * populated and used only by the en_lflow node. Ideally this data should
> +     * be maintained as part of en_lflow's data (struct lflow_data): a hash
> +     * index from ovn_port key to lflows.  However, it would be less efficient
> +     * and more complex:
> +     *
> +     * 1. It would require an extra search (using the index) to find the
> +     * lflows.
> +     *
> +     * 2. Building the index needs to be thread-safe, using either a global
> +     * lock which is obviously less efficient, or hash-based lock array which
> +     * is more complex.
> +     *
> +     * Adding the list here is more straightforward. The drawback is that we
> +     * need to keep in mind that this data belongs to en_lflow node, so never
> +     * access it from any other nodes.
> +     */
> +    struct ovs_list lflows;
> +};
> +
>  void ovnnb_db_run(struct northd_input *input_data,
>                    struct northd_data *data,
>                    struct ovsdb_idl_txn *ovnnb_txn,
> @@ -396,13 +507,27 @@ void sync_lbs(struct ovsdb_idl_txn *, const struct sbrec_load_balancer_table *,
>                struct chassis_features *chassis_features);
>  bool check_sb_lb_duplicates(const struct sbrec_load_balancer_table *);
>  
> +struct lr_lb_nat_data_table;
>  void sync_pbs(struct ovsdb_idl_txn *, struct hmap *ls_ports,
> -              struct hmap *lr_ports, const struct lr_nat_table *);
> -bool sync_pbs_for_northd_changed_ovn_ports(struct tracked_ovn_ports *,
> -                                           const struct lr_nat_table *);
> +              struct hmap *lr_ports,
> +              const struct lr_lb_nat_data_table *);
> +bool sync_pbs_for_northd_changed_ovn_ports(
> +    struct tracked_ovn_ports *,
> +    const struct lr_lb_nat_data_table *);
>  
>  bool northd_has_tracked_data(struct northd_tracked_data *);
>  bool northd_has_only_ports_in_tracked_data(struct northd_tracked_data *);
>  bool northd_has_lbs_in_tracked_data(struct northd_tracked_data *);
>  
> +/* Returns 'true' if the IPv4 'addr' is on the same subnet with one of the
> + * IPs configured on the router port.
> + */
> +bool lrouter_port_ipv4_reachable(const struct ovn_port *, ovs_be32 addr);
> +
> +/* Returns 'true' if the IPv6 'addr' is on the same subnet with one of the
> + * IPs configured on the router port.
> + */
> +bool lrouter_port_ipv6_reachable(const struct ovn_port *,
> +                                 const struct in6_addr *);
> +
>  #endif /* NORTHD_H */
> diff --git a/tests/ovn-northd.at b/tests/ovn-northd.at
> index b7f9cb5689..8fc5cd1d60 100644
> --- a/tests/ovn-northd.at
> +++ b/tests/ovn-northd.at
> @@ -10416,18 +10416,21 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb set load_balancer . ip_port_mappings:10.0.0.3=sw0-p1:10.0.0.2
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>  
>  check ovn-nbctl --wait=sb set load_balancer . options:foo=bar
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>  
>  check ovn-nbctl --wait=sb -- lb-add lb2 20.0.0.10:80 20.0.0.20:80 -- lb-add lb3 30.0.0.10:80 30.0.0.20:80
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>  
> @@ -10437,6 +10440,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb -- lb-del lb2 -- lb-del lb3
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>  
> @@ -10450,6 +10454,7 @@ AT_CHECK([ovn-nbctl --wait=sb \
>  ])
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>  
> @@ -10467,6 +10472,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb clear Load_Balancer . health_check
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>  
> @@ -10481,6 +10487,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  ovn-nbctl --wait=sb lsp-set-options sw0-lr0 router-port=lr0-sw0
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>  
> @@ -10489,6 +10496,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb ls-lb-add sw0 lb1
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  # A LB applied to a switch/router triggers:
>  # - a recompute in the first iteration (handling northd change)
> @@ -10501,6 +10509,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb set load_balancer lb1 vips:'"10.0.0.10:80"'='"10.0.0.100:80"'
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10510,6 +10519,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb clear load_Balancer lb1 vips
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10519,6 +10529,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lb-add lb1 10.0.0.10:80 10.0.0.3:80
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10528,6 +10539,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lb-add lb1 10.0.0.20:80 10.0.0.30:8080
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10537,6 +10549,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb ls-lb-del sw0 lb1
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10547,6 +10560,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb ls-lb-add sw0 lb1 -- lsp-add sw0 sw0p1
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  
> @@ -10567,6 +10581,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lr-lb-add lr0 lb1
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10576,6 +10591,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb set load_balancer lb1 vips:'"10.0.0.10:80"'='"10.0.0.100:80"'
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10585,6 +10601,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb clear load_Balancer lb1 vips
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10594,6 +10611,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lb-add lb1 10.0.0.10:80 10.0.0.3:80
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10603,6 +10621,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lb-add lb1 10.0.0.20:80 10.0.0.30:8080
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10632,6 +10651,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb add load_balancer_group . load_Balancer $lb1_uuid
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>  
> @@ -10639,6 +10659,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb clear load_balancer_group . load_Balancer
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>  
> @@ -10655,6 +10676,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb add logical_switch sw0 load_balancer_group $lbg1_uuid
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  
> @@ -10671,6 +10693,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb set load_balancer lb1 vips:'"10.0.0.10:80"'='"10.0.0.100:80"'
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10680,6 +10703,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb clear load_Balancer lb1 vips
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10689,6 +10713,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lb-add lb1 10.0.0.10:80 10.0.0.3:80
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10698,6 +10723,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lb-add lb1 10.0.0.20:80 10.0.0.30:8080
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10713,6 +10739,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl add logical_router lr0 load_balancer_group $lbg1_uuid
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10722,6 +10749,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb set load_balancer lb1 vips:'"10.0.0.10:80"'='"10.0.0.100:80"'
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10731,6 +10759,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb clear load_Balancer lb1 vips
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10740,6 +10769,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lb-add lb1 10.0.0.10:80 10.0.0.3:80
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10749,6 +10779,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lb-add lb1 10.0.0.20:80 10.0.0.30:8080
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10757,6 +10788,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb clear logical_router lr0 load_balancer_group
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  
> @@ -10765,6 +10797,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb add logical_switch sw0 load_balancer_group $lbg1_uuid
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  
> @@ -10773,6 +10806,7 @@ check ovn-nbctl --wait=sb clear logical_switch sw0 load_balancer_group -- \
>      destroy load_balancer_group $lbg1_uuid
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb compute compute
>  
> @@ -10796,6 +10830,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  lbg1_uuid=$(ovn-nbctl --wait=sb create load_balancer_group name=lbg1)
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow norecompute nocompute
>  check_engine_stats sync_to_sb_lb norecompute nocompute
>  
> @@ -10803,6 +10838,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb set load_balancer_group . load_balancer="$lb2_uuid,$lb3_uuid,$lb4_uuid"
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>  
> @@ -10810,6 +10846,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb set logical_switch sw0 load_balancer_group=$lbg1_uuid
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10818,6 +10855,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb set logical_router lr1 load_balancer_group=$lbg1_uuid
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10826,6 +10864,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb ls-lb-add sw0 lb2
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10834,6 +10873,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb ls-lb-add sw0 lb3
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10843,6 +10883,7 @@ check ovn-nbctl --wait=sb lr-lb-add lr1 lb1
>  check ovn-nbctl --wait=sb lr-lb-add lr1 lb2
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10851,6 +10892,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb ls-lb-del sw0 lb2
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10859,6 +10901,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lr-lb-del lr1 lb2
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10869,6 +10912,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lb-del lb4
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10879,6 +10923,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lb-del lb2
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -10887,6 +10932,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb remove load_balancer_group . load_balancer $lb3_uuid
>  check_engine_stats lb_data norecompute compute
>  check_engine_stats northd recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_lb recompute compute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11019,6 +11065,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lr-add lr0
>  check_engine_stats northd recompute nocompute
>  check_engine_stats lr_nat recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11031,6 +11078,7 @@ check ovn-nbctl lrp-add lr0 lr0-sw0 00:00:00:00:ff:01 10.0.0.1/24
>  # for the SB port binding change.
>  check_engine_stats northd recompute compute
>  check_engine_stats lr_nat recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11042,6 +11090,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lsp-set-options sw0-lr0 router-port=lr0-sw0
>  check_engine_stats northd recompute nocompute
>  check_engine_stats lr_nat recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11067,6 +11116,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl set logical_router_port lr0-sw0 options:foo=bar
>  check_engine_stats northd recompute nocompute
>  check_engine_stats lr_nat recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11076,8 +11126,8 @@ CHECK_NO_CHANGE_AFTER_RECOMPUTE
>  # engine nodes.
>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lr-nat-add lr0 dnat_and_snat  172.168.0.110 10.0.0.4
> -check_engine_stats northd recompute nocompute
> -check_engine_stats lr_nat recompute nocompute
> +check_engine_stats northd norecompute compute
> +check_engine_stats lr_nat norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11085,8 +11135,8 @@ CHECK_NO_CHANGE_AFTER_RECOMPUTE
>  # Update the NAT options column
>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb set NAT . options:foo=bar
> -check_engine_stats northd recompute nocompute
> -check_engine_stats lr_nat recompute nocompute
> +check_engine_stats northd norecompute compute
> +check_engine_stats lr_nat norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11094,8 +11144,9 @@ CHECK_NO_CHANGE_AFTER_RECOMPUTE
>  # Update the NAT external_ip column
>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb set NAT . external_ip=172.168.0.120
> -check_engine_stats northd recompute nocompute
> -check_engine_stats lr_nat recompute nocompute
> +check_engine_stats northd norecompute compute
> +check_engine_stats lr_nat norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11103,8 +11154,9 @@ CHECK_NO_CHANGE_AFTER_RECOMPUTE
>  # Update the NAT logical_ip column
>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb set NAT . logical_ip=10.0.0.10
> -check_engine_stats northd recompute nocompute
> -check_engine_stats lr_nat recompute nocompute
> +check_engine_stats northd norecompute compute
> +check_engine_stats lr_nat norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11112,8 +11164,9 @@ CHECK_NO_CHANGE_AFTER_RECOMPUTE
>  # Update the NAT type
>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb set NAT . type=snat
> -check_engine_stats northd recompute nocompute
> -check_engine_stats lr_nat recompute nocompute
> +check_engine_stats northd norecompute compute
> +check_engine_stats lr_nat norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11121,8 +11174,9 @@ CHECK_NO_CHANGE_AFTER_RECOMPUTE
>  # Create a dnat_and_snat NAT with external_mac and logical_port
>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lr-nat-add lr0 dnat_and_snat 172.168.0.110 10.0.0.4 sw0p1 30:54:00:00:00:03
> -check_engine_stats northd recompute compute
> -check_engine_stats lr_nat recompute nocompute
> +check_engine_stats northd norecompute compute
> +check_engine_stats lr_nat norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11131,8 +11185,9 @@ nat2_uuid=$(ovn-nbctl --bare --columns _uuid find nat logical_ip=10.0.0.4)
>  
>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb set NAT $nat2_uuid external_mac='"30:54:00:00:00:04"'
> -check_engine_stats northd recompute nocompute
> -check_engine_stats lr_nat recompute nocompute
> +check_engine_stats northd norecompute compute
> +check_engine_stats lr_nat norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11147,32 +11202,36 @@ check ovn-nbctl lr-lb-add lr0 lb2
>  # is a lb vip.
>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lr-nat-add lr0 dnat_and_snat 172.168.0.140 10.0.0.20
> -check_engine_stats northd recompute nocompute
> -check_engine_stats lr_nat recompute nocompute
> +check_engine_stats northd norecompute compute
> +check_engine_stats lr_nat norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>  
>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lr-nat-add lr0 dnat_and_snat 172.168.0.150 10.0.0.41
> -check_engine_stats northd recompute nocompute
> -check_engine_stats lr_nat recompute nocompute
> +check_engine_stats northd norecompute compute
> +check_engine_stats lr_nat norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>  
>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lr-nat-del lr0 dnat_and_snat 172.168.0.150
> -check_engine_stats northd recompute nocompute
> -check_engine_stats lr_nat recompute nocompute
> +check_engine_stats northd norecompute compute
> +check_engine_stats lr_nat norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>  
>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lr-nat-del lr0 dnat_and_snat 172.168.0.140
> -check_engine_stats northd recompute nocompute
> -check_engine_stats lr_nat recompute nocompute
> +check_engine_stats northd norecompute compute
> +check_engine_stats lr_nat norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11180,8 +11239,9 @@ CHECK_NO_CHANGE_AFTER_RECOMPUTE
>  # Delete the NAT
>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb clear logical_router lr0 nat
> -check_engine_stats northd recompute compute
> -check_engine_stats lr_nat recompute nocompute
> +check_engine_stats northd norecompute compute
> +check_engine_stats lr_nat norecompute compute
> +check_engine_stats lr_lb_nat_data norecompute compute
>  check_engine_stats lflow recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11191,6 +11251,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lr-policy-add lr0  10 "ip4.src == 10.0.0.3" reroute 172.168.0.101,172.168.0.102
>  check_engine_stats northd recompute nocompute
>  check_engine_stats lr_nat recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
> @@ -11199,6 +11260,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>  check ovn-nbctl --wait=sb lr-policy-del lr0  10 "ip4.src == 10.0.0.3"
>  check_engine_stats northd recompute nocompute
>  check_engine_stats lr_nat recompute nocompute
> +check_engine_stats lr_lb_nat_data recompute nocompute
>  check_engine_stats sync_to_sb_pb recompute nocompute
>  check_engine_stats lflow recompute nocompute
>  CHECK_NO_CHANGE_AFTER_RECOMPUTE

On 11/23/23 21:45, Dumitru Ceara wrote:
> On 10/26/23 20:15, numans@ovn.org wrote:
>> From: Numan Siddique <numans@ovn.org>
>>
>> This new engine now maintains the load balancer and NAT data of a
>> logical router which was earlier part of northd engine node data.
>> The main inputs to this engine are:
>>    - northd node
>>    - lr-nat node
>>
>> A record for each logical router is maintained in the 'lr_lb_nats'
>> hmap table and this record
>>    - stores the lb related data
>>    - embeds the 'lr-nat' record.
>>
>> This engine node becomes an input to 'lflow' node.
>>
>> Signed-off-by: Numan Siddique <numans@ovn.org>
>> ---
>>  lib/stopwatch-names.h      |   1 +
>>  northd/automake.mk         |   2 +
>>  northd/en-lflow.c          |   4 +
>>  northd/en-lr-lb-nat-data.c | 654 +++++++++++++++++++++++++++++++++++++
>>  northd/en-lr-lb-nat-data.h |  93 ++++++
>>  northd/en-lr-nat.h         |   3 +
>>  northd/en-sync-sb.c        |  50 +--
>>  northd/inc-proc-northd.c   |  13 +-
>>  northd/northd.c            | 640 ++++++++++++------------------------
>>  northd/northd.h            | 137 +++++++-
>>  tests/ovn-northd.at        | 110 +++++--
>>  11 files changed, 1212 insertions(+), 495 deletions(-)
>>  create mode 100644 northd/en-lr-lb-nat-data.c
>>  create mode 100644 northd/en-lr-lb-nat-data.h
>>
>> diff --git a/lib/stopwatch-names.h b/lib/stopwatch-names.h
>> index 0a16da211e..7d85acdaea 100644
>> --- a/lib/stopwatch-names.h
>> +++ b/lib/stopwatch-names.h
>> @@ -33,5 +33,6 @@
>>  #define PORT_GROUP_RUN_STOPWATCH_NAME "port_group_run"
>>  #define SYNC_METERS_RUN_STOPWATCH_NAME "sync_meters_run"
>>  #define LR_NAT_RUN_STOPWATCH_NAME "lr_nat_run"
>> +#define LR_LB_NAT_DATA_RUN_STOPWATCH_NAME "lr_lb_nat_data"
>>  
>>  #endif
>> diff --git a/northd/automake.mk b/northd/automake.mk
>> index ae367a2a8b..4116c487df 100644
>> --- a/northd/automake.mk
>> +++ b/northd/automake.mk
>> @@ -26,6 +26,8 @@ northd_ovn_northd_SOURCES = \
>>  	northd/en-lb-data.h \
>>  	northd/en-lr-nat.c \
>>  	northd/en-lr-nat.h \
>> +	northd/en-lr-lb-nat-data.c \
>> +	northd/en-lr-lb-nat-data.h \
>>  	northd/inc-proc-northd.c \
>>  	northd/inc-proc-northd.h \
>>  	northd/ipam.c \
>> diff --git a/northd/en-lflow.c b/northd/en-lflow.c
>> index 22f398d419..9cb0ead3f0 100644
>> --- a/northd/en-lflow.c
>> +++ b/northd/en-lflow.c
>> @@ -20,6 +20,7 @@
>>  
>>  #include "en-lflow.h"
>>  #include "en-lr-nat.h"
>> +#include "en-lr-lb-nat-data.h"
>>  #include "en-northd.h"
>>  #include "en-meters.h"
>>  
>> @@ -43,6 +44,8 @@ lflow_get_input_data(struct engine_node *node,
>>          engine_get_input_data("sync_meters", node);
>>      struct ed_type_lr_nat_data *lr_nat_data =
>>          engine_get_input_data("lr_nat", node);
>> +    struct ed_type_lr_lb_nat_data *lr_lb_nat_data =
>> +        engine_get_input_data("lr_lb_nat_data", node);
>>  
>>      lflow_input->nbrec_bfd_table =
>>          EN_OVSDB_GET(engine_get_input("NB_bfd", node));
>> @@ -66,6 +69,7 @@ lflow_get_input_data(struct engine_node *node,
>>      lflow_input->lr_ports = &northd_data->lr_ports;
>>      lflow_input->ls_port_groups = &pg_data->ls_port_groups;
>>      lflow_input->lr_nats = &lr_nat_data->lr_nats;
>> +    lflow_input->lr_lbnats = &lr_lb_nat_data->lr_lbnats;
>>      lflow_input->meter_groups = &sync_meters_data->meter_groups;
>>      lflow_input->lb_datapaths_map = &northd_data->lb_datapaths_map;
>>      lflow_input->svc_monitor_map = &northd_data->svc_monitor_map;
>> diff --git a/northd/en-lr-lb-nat-data.c b/northd/en-lr-lb-nat-data.c
>> new file mode 100644
>> index 0000000000..19b638ce0b
>> --- /dev/null
>> +++ b/northd/en-lr-lb-nat-data.c
>> @@ -0,0 +1,654 @@
>> +/*
>> + * Copyright (c) 2023, Red Hat, Inc.
>> + *
>> + * Licensed under the Apache License, Version 2.0 (the "License");
>> + * you may not use this file except in compliance with the License.
>> + * You may obtain a copy of the License at:
>> + *
>> + *     http://www.apache.org/licenses/LICENSE-2.0
>> + *
>> + * Unless required by applicable law or agreed to in writing, software
>> + * distributed under the License is distributed on an "AS IS" BASIS,
>> + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
>> + * See the License for the specific language governing permissions and
>> + * limitations under the License.
>> + */
>> +
>> +#include <config.h>
>> +
>> +#include <getopt.h>
>> +#include <stdlib.h>
>> +#include <stdio.h>
>> +
>> +/* OVS includes */
>> +#include "include/openvswitch/hmap.h"
>> +#include "lib/bitmap.h"
>> +#include "lib/socket-util.h"
>> +#include "lib/uuidset.h"
>> +#include "openvswitch/util.h"
>> +#include "openvswitch/vlog.h"
>> +#include "stopwatch.h"
>> +
>> +/* OVN includes */
>> +#include "en-lb-data.h"
>> +#include "en-lr-lb-nat-data.h"
>> +#include "en-lr-nat.h"
>> +#include "lib/inc-proc-eng.h"
>> +#include "lib/lb.h"
>> +#include "lib/ovn-nb-idl.h"
>> +#include "lib/ovn-sb-idl.h"
>> +#include "lib/ovn-util.h"
>> +#include "lib/stopwatch-names.h"
>> +#include "northd.h"
>> +
>> +VLOG_DEFINE_THIS_MODULE(en_lr_lb_nat_data);
>> +
>> +/* Static function declarations. */
>> +static void lr_lb_nat_data_table_init(struct lr_lb_nat_data_table *);
>> +static void lr_lb_nat_data_table_clear(struct lr_lb_nat_data_table *);
>> +static void lr_lb_nat_data_table_destroy(struct lr_lb_nat_data_table *);
>> +static struct lr_lb_nat_data_record *lr_lb_nat_data_table_find_(
>> +    const struct lr_lb_nat_data_table *, const struct nbrec_logical_router *);
>> +static struct lr_lb_nat_data_record *lr_lb_nat_data_table_find_by_index_(
>> +    const struct lr_lb_nat_data_table *table, size_t od_index);
>> +
>> +static void lr_lb_nat_data_table_build(struct lr_lb_nat_data_table *,
>> +                                   const struct lr_nat_table *,
>> +                                   const struct ovn_datapaths *lr_datapaths,
>> +                                   const struct hmap *lb_datapaths_map,
>> +                                   const struct hmap *lbgrp_datapaths_map);
>> +
>> +static struct lr_lb_nat_data_input lr_lb_nat_data_get_input_data(
>> +    struct engine_node *);
>> +
>> +static struct lr_lb_nat_data_record *lr_lb_nat_data_record_create(
>> +    struct lr_lb_nat_data_table *, const struct lr_nat_record *,
>> +    const struct hmap *lb_datapaths_map,
>> +    const struct hmap *lbgrp_datapaths_map);
>> +static void lr_lb_nat_data_record_destroy(struct lr_lb_nat_data_record *);
>> +static void lr_lb_nat_data_record_init(
>> +    struct lr_lb_nat_data_record *,
>> +    const struct hmap *lb_datapaths_map,
>> +    const struct hmap *lbgrp_datapaths_map);
>> +
>> +static void build_lrouter_lb_reachable_ips(struct lr_lb_nat_data_record *,
>> +                                           const struct ovn_northd_lb *);
>> +static void add_neigh_ips_to_lrouter(struct lr_lb_nat_data_record *,
>> +                                     enum lb_neighbor_responder_mode,
>> +                                     const struct sset *lb_ips_v4,
>> +                                     const struct sset *lb_ips_v6);
>> +static void remove_lrouter_lb_reachable_ips(struct lr_lb_nat_data_record *,
>> +                                            enum lb_neighbor_responder_mode,
>> +                                            const struct sset *lb_ips_v4,
>> +                                            const struct sset *lb_ips_v6);
>> +static void lr_lb_nat_data_build_vip_nats(struct lr_lb_nat_data_record *);
>> +
>> +/* 'lr_lb_nat_data' engine node manages the NB logical router LB data.
>> + */
>> +void *
>> +en_lr_lb_nat_data_init(struct engine_node *node OVS_UNUSED,
>> +               struct engine_arg *arg OVS_UNUSED)
>> +{
>> +    struct ed_type_lr_lb_nat_data *data = xzalloc(sizeof *data);
>> +    lr_lb_nat_data_table_init(&data->lr_lbnats);
>> +    hmapx_init(&data->tracked_data.crupdated);
>> +    hmapx_init(&data->tracked_data.deleted);
>> +    return data;
>> +}
>> +
>> +void
>> +en_lr_lb_nat_data_cleanup(void *data_)
>> +{
>> +    struct ed_type_lr_lb_nat_data *data =
>> +        (struct ed_type_lr_lb_nat_data *) data_;
>> +    lr_lb_nat_data_table_destroy(&data->lr_lbnats);
>> +    hmapx_destroy(&data->tracked_data.crupdated);
>> +    hmapx_destroy(&data->tracked_data.deleted);
>> +}
>> +
>> +void
>> +en_lr_lb_nat_data_clear_tracked_data(void *data_)
>> +{
>> +    struct ed_type_lr_lb_nat_data *data =
>> +        (struct ed_type_lr_lb_nat_data *) data_;
>> +
>> +    struct hmapx_node *hmapx_node;
>> +    HMAPX_FOR_EACH_SAFE (hmapx_node, &data->tracked_data.deleted) {
>> +        lr_lb_nat_data_record_destroy(hmapx_node->data);
>> +        hmapx_delete(&data->tracked_data.deleted, hmapx_node);
>> +    }
>> +
>> +    hmapx_clear(&data->tracked_data.crupdated);
>> +    data->tracked = false;
>> +}
>> +
>> +void
>> +en_lr_lb_nat_data_run(struct engine_node *node, void *data_)
>> +{
>> +    struct lr_lb_nat_data_input input_data =
>> +        lr_lb_nat_data_get_input_data(node);
>> +    struct ed_type_lr_lb_nat_data *data = data_;
>> +
>> +    stopwatch_start(LR_LB_NAT_DATA_RUN_STOPWATCH_NAME, time_msec());
>> +
>> +    lr_lb_nat_data_table_clear(&data->lr_lbnats);
>> +    lr_lb_nat_data_table_build(&data->lr_lbnats, input_data.lr_nats,
>> +                               input_data.lr_datapaths,
>> +                               input_data.lb_datapaths_map,
>> +                               input_data.lbgrp_datapaths_map);
>> +
>> +    stopwatch_stop(LR_LB_NAT_DATA_RUN_STOPWATCH_NAME, time_msec());
>> +    engine_set_node_state(node, EN_UPDATED);
>> +}
>> +
>> +bool
>> +lr_lb_nat_data_northd_handler(struct engine_node *node, void *data OVS_UNUSED)
>> +{
>> +    struct northd_data *northd_data = engine_get_input_data("northd", node);
>> +    if (!northd_data->change_tracked) {
>> +        return false;
>> +    }
>> +
>> +    return true;
>> +}
>> +
>> +bool
>> +lr_lb_nat_data_lb_data_handler(struct engine_node *node, void *data_)
>> +{
>> +    struct ed_type_lb_data *lb_data = engine_get_input_data("lb_data", node);
>> +    if (!lb_data->tracked) {
>> +        return false;
>> +    }
>> +
>> +    struct ed_type_lr_lb_nat_data *data =
>> +        (struct ed_type_lr_lb_nat_data *) data_;
>> +    struct lr_lb_nat_data_input input_data =
>> +        lr_lb_nat_data_get_input_data(node);
>> +    struct lr_lb_nat_data_record *lr_lbnat_rec;
>> +    size_t index;
>> +
>> +    const struct tracked_lb_data *trk_lb_data = &lb_data->tracked_lb_data;
>> +    const struct ovn_lb_group_datapaths *lbgrp_dps;
>> +    const struct crupdated_lbgrp *crupdated_lbgrp;
>> +    const struct crupdated_od_lb_data *codlb;
>> +    const struct ovn_lb_datapaths *lb_dps;
>> +    const struct crupdated_lb *clb;
>> +    const struct ovn_northd_lb *lb;
>> +    const struct ovn_datapath *od;
>> +
>> +    LIST_FOR_EACH (codlb, list_node, &trk_lb_data->crupdated_lr_lbs) {
>> +        od = ovn_datapath_find(&input_data.lr_datapaths->datapaths,
>> +                               &codlb->od_uuid);
>> +        ovs_assert(od);
>> +
>> +        lr_lbnat_rec = lr_lb_nat_data_table_find_(&data->lr_lbnats, od->nbr);
>> +        if (!lr_lbnat_rec) {
>> +            const struct lr_nat_record *lrnat_rec = lr_nat_table_find_by_index(
>> +                input_data.lr_nats, od->index);
>> +            ovs_assert(lrnat_rec);
>> +
>> +            lr_lbnat_rec = lr_lb_nat_data_record_create(&data->lr_lbnats,
>> +                                            lrnat_rec,
>> +                                            input_data.lb_datapaths_map,
>> +                                            input_data.lbgrp_datapaths_map);
>> +
>> +            /* Add the lr_lbnat_rec rec to the tracking data. */
>> +            hmapx_add(&data->tracked_data.crupdated, lr_lbnat_rec);
>> +            continue;
>> +        }
>> +
>> +        struct uuidset_node *uuidnode;
>> +        UUIDSET_FOR_EACH (uuidnode, &codlb->assoc_lbs) {
>> +            lb_dps = ovn_lb_datapaths_find(
>> +                input_data.lb_datapaths_map, &uuidnode->uuid);
>> +            ovs_assert(lb_dps);
>> +
>> +            /* Add the lb_ips of lb_dps to the od. */
>> +            build_lrouter_lb_ips(lr_lbnat_rec->lb_ips, lb_dps->lb);
>> +            build_lrouter_lb_reachable_ips(lr_lbnat_rec, lb_dps->lb);
>> +        }
>> +
>> +        UUIDSET_FOR_EACH (uuidnode, &codlb->assoc_lbgrps) {
>> +            lbgrp_dps = ovn_lb_group_datapaths_find(
>> +                input_data.lbgrp_datapaths_map, &uuidnode->uuid);
>> +            ovs_assert(lbgrp_dps);
>> +
>> +            for (size_t j = 0; j < lbgrp_dps->lb_group->n_lbs; j++) {
>> +                const struct uuid *lb_uuid
>> +                    = &lbgrp_dps->lb_group->lbs[j]->nlb->header_.uuid;
>> +                lb_dps = ovn_lb_datapaths_find(input_data.lb_datapaths_map,
>> +                                               lb_uuid);
>> +                ovs_assert(lb_dps);
>> +
>> +                /* Add the lb_ips of lb_dps to the od. */
>> +                build_lrouter_lb_ips(lr_lbnat_rec->lb_ips, lb_dps->lb);
>> +                build_lrouter_lb_reachable_ips(lr_lbnat_rec, lb_dps->lb);
>> +            }
>> +        }
>> +
>> +        /* Add the lr_lbnat_rec rec to the tracking data. */
>> +        hmapx_add(&data->tracked_data.crupdated, lr_lbnat_rec);
>> +    }
>> +
>> +    HMAP_FOR_EACH (clb, hmap_node, &trk_lb_data->crupdated_lbs) {
>> +        lb = clb->lb;
>> +        const struct uuid *lb_uuid = &lb->nlb->header_.uuid;
>> +
>> +        lb_dps = ovn_lb_datapaths_find(input_data.lb_datapaths_map, lb_uuid);
>> +        ovs_assert(lb_dps);
>> +
>> +        BITMAP_FOR_EACH_1 (index, ods_size(input_data.lr_datapaths),
>> +                           lb_dps->nb_lr_map) {
>> +            od = input_data.lr_datapaths->array[index];
>> +
>> +            lr_lbnat_rec = lr_lb_nat_data_table_find_(&data->lr_lbnats,
>> +                                                      od->nbr);
>> +            ovs_assert(lr_lbnat_rec);
>> +
>> +            /* Update the od->lb_ips with the deleted and inserted
>> +             * vips (if any). */
>> +            remove_ips_from_lb_ip_set(lr_lbnat_rec->lb_ips, lb->routable,
>> +                                      &clb->deleted_vips_v4,
>> +                                      &clb->deleted_vips_v6);
>> +            add_ips_to_lb_ip_set(lr_lbnat_rec->lb_ips, lb->routable,
>> +                                 &clb->inserted_vips_v4,
>> +                                 &clb->inserted_vips_v6);
>> +
>> +            remove_lrouter_lb_reachable_ips(lr_lbnat_rec, lb->neigh_mode,
>> +                                            &clb->deleted_vips_v4,
>> +                                            &clb->deleted_vips_v6);
>> +            add_neigh_ips_to_lrouter(lr_lbnat_rec, lb->neigh_mode,
>> +                                     &clb->inserted_vips_v4,
>> +                                     &clb->inserted_vips_v6);
>> +
>> +            /* Add the lr_lbnat_rec rec to the tracking data. */
>> +            hmapx_add(&data->tracked_data.crupdated, lr_lbnat_rec);
>> +        }
>> +    }
>> +
>> +    HMAP_FOR_EACH (crupdated_lbgrp, hmap_node,
>> +                   &trk_lb_data->crupdated_lbgrps) {
>> +        const struct uuid *lb_uuid = &crupdated_lbgrp->lbgrp->uuid;
>> +
>> +        lbgrp_dps = ovn_lb_group_datapaths_find(input_data.lbgrp_datapaths_map,
>> +                                                lb_uuid);
>> +        ovs_assert(lbgrp_dps);
>> +
>> +        struct hmapx_node *hnode;
>> +        HMAPX_FOR_EACH (hnode, &crupdated_lbgrp->assoc_lbs) {
>> +            lb = hnode->data;
>> +            lb_uuid = &lb->nlb->header_.uuid;
>> +            lb_dps = ovn_lb_datapaths_find(input_data.lb_datapaths_map,
>> +                                           lb_uuid);
>> +            ovs_assert(lb_dps);
>> +            for (size_t i = 0; i < lbgrp_dps->n_lr; i++) {
>> +                od = lbgrp_dps->lr[i];
>> +                lr_lbnat_rec = lr_lb_nat_data_table_find_(&data->lr_lbnats,
>> +                                                          od->nbr);
>> +                ovs_assert(lr_lbnat_rec);
>> +                /* Add the lb_ips of lb_dps to the lr lb data. */
>> +                build_lrouter_lb_ips(lr_lbnat_rec->lb_ips, lb_dps->lb);
>> +                build_lrouter_lb_reachable_ips(lr_lbnat_rec, lb_dps->lb);
>> +
>> +                /* Add the lr_lbnat_rec rec to the tracking data. */
>> +                hmapx_add(&data->tracked_data.crupdated, lr_lbnat_rec);
>> +            }
>> +        }
>> +    }
>> +
>> +    if (!hmapx_is_empty(&data->tracked_data.crupdated)) {
>> +        struct hmapx_node *hmapx_node;
>> +        /* For all the modified lr_lb_nat_data records (re)build the
>> +         * vip nats. */
>> +        HMAPX_FOR_EACH (hmapx_node, &data->tracked_data.crupdated) {
>> +            lr_lb_nat_data_build_vip_nats(hmapx_node->data);
>> +        }
>> +
>> +        data->tracked = true;
>> +        engine_set_node_state(node, EN_UPDATED);
>> +    }
>> +
>> +    return true;
>> +}
>> +
>> +bool
>> +lr_lb_nat_data_lr_nat_handler(struct engine_node *node, void *data_)
>> +{
>> +    struct ed_type_lr_nat_data *lr_nat_data =
>> +        engine_get_input_data("lr_nat", node);
>> +
>> +    if (!lr_nat_data->tracked
>> +        || !hmapx_is_empty(&lr_nat_data->tracked_data.deleted)) {
>> +        return false;
>> +    }
>> +
>> +    struct ed_type_lr_lb_nat_data *data =
>> +        (struct ed_type_lr_lb_nat_data *) data_;
>> +    struct lr_lb_nat_data_input input_data =
>> +        lr_lb_nat_data_get_input_data(node);
>> +    const struct lr_nat_record *lrnat_rec;
>> +    struct lr_lb_nat_data_record *lr_lbnat_rec;
>> +    struct hmapx_node *hmapx_node;
>> +
>> +    HMAPX_FOR_EACH (hmapx_node, &lr_nat_data->tracked_data.crupdated) {
>> +        lrnat_rec = hmapx_node->data;
>> +        lr_lbnat_rec = lr_lb_nat_data_table_find_(&data->lr_lbnats,
>> +                                                  lrnat_rec->od->nbr);
>> +        if (!lr_lbnat_rec) {
>> +            lr_lbnat_rec = lr_lb_nat_data_record_create(&data->lr_lbnats,
>> +                                            lrnat_rec,
>> +                                            input_data.lb_datapaths_map,
>> +                                            input_data.lbgrp_datapaths_map);
>> +        } else {
>> +            lr_lb_nat_data_build_vip_nats(lr_lbnat_rec);
>> +        }
>> +
>> +        /* Add the lr_lbnat_rec rec to the tracking data. */
>> +        hmapx_add(&data->tracked_data.crupdated, lr_lbnat_rec);
>> +    }
>> +
>> +    if (!hmapx_is_empty(&data->tracked_data.crupdated)) {
>> +        data->tracked = true;
>> +        engine_set_node_state(node, EN_UPDATED);
>> +    }
>> +
>> +    return true;
>> +}
>> +
>> +const struct lr_lb_nat_data_record *
>> +lr_lb_nat_data_table_find_by_index(const struct lr_lb_nat_data_table *table,
>> +                                   size_t od_index)
>> +{
>> +    return lr_lb_nat_data_table_find_by_index_(table, od_index);
>> +}
>> +
>> +/* static functions. */
>> +static void
>> +lr_lb_nat_data_table_init(struct lr_lb_nat_data_table *table)
>> +{
>> +    *table = (struct lr_lb_nat_data_table) {
>> +        .entries = HMAP_INITIALIZER(&table->entries),
>> +    };
>> +}
>> +
>> +static void
>> +lr_lb_nat_data_table_destroy(struct lr_lb_nat_data_table *table)
>> +{
>> +    lr_lb_nat_data_table_clear(table);
>> +    hmap_destroy(&table->entries);
>> +}
>> +
>> +static void
>> +lr_lb_nat_data_table_clear(struct lr_lb_nat_data_table *table)
>> +{
>> +    struct lr_lb_nat_data_record *lr_lbnat_rec;
>> +    HMAP_FOR_EACH_POP (lr_lbnat_rec, key_node, &table->entries) {
>> +        lr_lb_nat_data_record_destroy(lr_lbnat_rec);
>> +    }
>> +
>> +    free(table->array);
>> +    table->array = NULL;
>> +}
>> +
>> +static void
>> +lr_lb_nat_data_table_build(struct lr_lb_nat_data_table *table,
>> +                       const struct lr_nat_table *lr_nats,
>> +                       const struct ovn_datapaths *lr_datapaths,
>> +                       const struct hmap *lb_datapaths_map,
>> +                       const struct hmap *lbgrp_datapaths_map)
>> +{
>> +    table->array = xrealloc(table->array,
>> +                            ods_size(lr_datapaths) * sizeof *table->array);
>> +    const struct lr_nat_record *lrnat_rec;
>> +    LR_NAT_TABLE_FOR_EACH (lrnat_rec, lr_nats) {
>> +        lr_lb_nat_data_record_create(table, lrnat_rec, lb_datapaths_map,
>> +                                     lbgrp_datapaths_map);
>> +    }
>> +}
>> +
>> +static struct lr_lb_nat_data_record *
>> +lr_lb_nat_data_table_find_(const struct lr_lb_nat_data_table *table,
>> +                  const struct nbrec_logical_router *nbr)
>> +{
>> +    struct lr_lb_nat_data_record *lr_lbnat_rec;
>> +
>> +    HMAP_FOR_EACH_WITH_HASH (lr_lbnat_rec, key_node,
>> +                             uuid_hash(&nbr->header_.uuid), &table->entries) {
>> +        if (nbr == lr_lbnat_rec->od->nbr) {
>> +            return lr_lbnat_rec;
>> +        }
>> +    }
>> +    return NULL;
>> +}
>> +
>> +static struct lr_lb_nat_data_record *
>> +lr_lb_nat_data_table_find_by_index_(const struct lr_lb_nat_data_table *table,
>> +                                   size_t od_index)
>> +{
>> +    ovs_assert(od_index <= hmap_count(&table->entries));
>> +    return table->array[od_index];
>> +}
>> +
>> +static struct lr_lb_nat_data_record *
>> +lr_lb_nat_data_record_create(struct lr_lb_nat_data_table *table,
>> +                         const struct lr_nat_record *lrnat_rec,
>> +                         const struct hmap *lb_datapaths_map,
>> +                         const struct hmap *lbgrp_datapaths_map)
>> +{
>> +    struct lr_lb_nat_data_record *lr_lbnat_rec = xzalloc(sizeof *lr_lbnat_rec);
>> +    lr_lbnat_rec->lrnat_rec = lrnat_rec;
>> +    lr_lbnat_rec->od = lrnat_rec->od;
>> +    lr_lb_nat_data_record_init(lr_lbnat_rec, lb_datapaths_map,
>> +                               lbgrp_datapaths_map);
>> +
>> +    hmap_insert(&table->entries, &lr_lbnat_rec->key_node,
>> +                uuid_hash(&lr_lbnat_rec->od->nbr->header_.uuid));
>> +
>> +    table->array[lr_lbnat_rec->od->index] = lr_lbnat_rec;
>> +    return lr_lbnat_rec;
>> +}
>> +
>> +static void
>> +lr_lb_nat_data_record_destroy(struct lr_lb_nat_data_record *lr_lbnat_rec)
>> +{
>> +    ovn_lb_ip_set_destroy(lr_lbnat_rec->lb_ips);
>> +    lr_lbnat_rec->lb_ips = NULL;
>> +    sset_destroy(&lr_lbnat_rec->vip_nats);
>> +    free(lr_lbnat_rec);
>> +}
>> +
>> +static void
>> +lr_lb_nat_data_record_init(struct lr_lb_nat_data_record *lr_lbnat_rec,
>> +                           const struct hmap *lb_datapaths_map,
>> +                           const struct hmap *lbgrp_datapaths_map)
>> +{
>> +    const struct nbrec_load_balancer_group *nbrec_lb_group;
>> +    const struct ovn_lb_group_datapaths *lb_group_dps;
>> +    const struct ovn_lb_datapaths *lb_dps;
>> +
>> +    /* Checking load balancer groups first, starting from the largest one,
>> +     * to more efficiently copy IP sets. */
>> +    size_t largest_group = 0;
>> +
>> +    const struct nbrec_logical_router *nbr = lr_lbnat_rec->od->nbr;
>> +    for (size_t i = 1; i < nbr->n_load_balancer_group; i++) {
>> +        if (nbr->load_balancer_group[i]->n_load_balancer >
>> +                nbr->load_balancer_group[largest_group]->n_load_balancer) {
>> +            largest_group = i;
>> +        }
>> +    }
>> +
>> +    for (size_t i = 0; i < nbr->n_load_balancer_group; i++) {
>> +        size_t idx = (i + largest_group) % nbr->n_load_balancer_group;
>> +
>> +        nbrec_lb_group = nbr->load_balancer_group[idx];
>> +        const struct uuid *lbgrp_uuid = &nbrec_lb_group->header_.uuid;
>> +
>> +        lb_group_dps =
>> +            ovn_lb_group_datapaths_find(lbgrp_datapaths_map,
>> +                                        lbgrp_uuid);
>> +        ovs_assert(lb_group_dps);
>> +
>> +        if (!lr_lbnat_rec->lb_ips) {
>> +            lr_lbnat_rec->lb_ips =
>> +                ovn_lb_ip_set_clone(lb_group_dps->lb_group->lb_ips);
>> +        } else {
>> +            for (size_t j = 0; j < lb_group_dps->lb_group->n_lbs; j++) {
>> +                build_lrouter_lb_ips(lr_lbnat_rec->lb_ips,
>> +                                     lb_group_dps->lb_group->lbs[j]);
>> +            }
>> +        }
>> +
>> +        for (size_t j = 0; j < lb_group_dps->lb_group->n_lbs; j++) {
>> +            build_lrouter_lb_reachable_ips(lr_lbnat_rec,
>> +                                           lb_group_dps->lb_group->lbs[j]);
>> +        }
>> +    }
>> +
>> +    if (!lr_lbnat_rec->lb_ips) {
>> +        lr_lbnat_rec->lb_ips = ovn_lb_ip_set_create();
>> +    }
>> +
>> +    for (size_t i = 0; i < nbr->n_load_balancer; i++) {
>> +        const struct uuid *lb_uuid =
>> +            &nbr->load_balancer[i]->header_.uuid;
>> +        lb_dps = ovn_lb_datapaths_find(lb_datapaths_map, lb_uuid);
>> +        ovs_assert(lb_dps);
>> +        build_lrouter_lb_ips(lr_lbnat_rec->lb_ips, lb_dps->lb);
>> +        build_lrouter_lb_reachable_ips(lr_lbnat_rec, lb_dps->lb);
>> +    }
>> +
>> +    sset_init(&lr_lbnat_rec->vip_nats);
>> +
>> +    if (!nbr->n_nat) {
>> +        lr_lb_nat_data_build_vip_nats(lr_lbnat_rec);
>> +    }
>> +}
>> +
>> +static struct lr_lb_nat_data_input
>> +lr_lb_nat_data_get_input_data(struct engine_node *node)
>> +{
>> +    struct northd_data *northd_data = engine_get_input_data("northd", node);
>> +    struct ed_type_lr_nat_data *lr_nat_data =
>> +        engine_get_input_data("lr_nat", node);
>> +
>> +    return (struct lr_lb_nat_data_input) {
>> +        .lr_datapaths = &northd_data->lr_datapaths,
>> +        .lb_datapaths_map = &northd_data->lb_datapaths_map,
>> +        .lbgrp_datapaths_map = &northd_data->lb_group_datapaths_map,
>> +        .lr_nats = &lr_nat_data->lr_nats,
>> +    };
>> +}
>> +
>> +static void
>> +build_lrouter_lb_reachable_ips(struct lr_lb_nat_data_record *lr_lbnat_rec,
>> +                               const struct ovn_northd_lb *lb)
>> +{
>> +    add_neigh_ips_to_lrouter(lr_lbnat_rec, lb->neigh_mode, &lb->ips_v4,
>> +                             &lb->ips_v6);
>> +}
>> +
>> +static void
>> +add_neigh_ips_to_lrouter(struct lr_lb_nat_data_record *lr_lbnat_rec,
>> +                         enum lb_neighbor_responder_mode neigh_mode,
>> +                         const struct sset *lb_ips_v4,
>> +                         const struct sset *lb_ips_v6)
>> +{
>> +    /* If configured to not reply to any neighbor requests for all VIPs
>> +     * return early.
>> +     */
>> +    if (neigh_mode == LB_NEIGH_RESPOND_NONE) {
>> +        return;
>> +    }
>> +
>> +    const char *ip_address;
>> +
>> +    /* If configured to reply to neighbor requests for all VIPs force them
>> +     * all to be considered "reachable".
>> +     */
>> +    if (neigh_mode == LB_NEIGH_RESPOND_ALL) {
>> +        SSET_FOR_EACH (ip_address, lb_ips_v4) {
>> +            sset_add(&lr_lbnat_rec->lb_ips->ips_v4_reachable, ip_address);
>> +        }
>> +        SSET_FOR_EACH (ip_address, lb_ips_v6) {
>> +            sset_add(&lr_lbnat_rec->lb_ips->ips_v6_reachable, ip_address);
>> +        }
>> +
>> +        return;
>> +    }
>> +
>> +    /* Otherwise, a VIP is reachable if there's at least one router
>> +     * subnet that includes it.
>> +     */
>> +    ovs_assert(neigh_mode == LB_NEIGH_RESPOND_REACHABLE);
>> +
>> +    SSET_FOR_EACH (ip_address, lb_ips_v4) {
>> +        struct ovn_port *op;
>> +        ovs_be32 vip_ip4;
>> +        if (ip_parse(ip_address, &vip_ip4)) {
>> +            HMAP_FOR_EACH (op, dp_node, &lr_lbnat_rec->od->ports) {
>> +                if (lrouter_port_ipv4_reachable(op, vip_ip4)) {
>> +                    sset_add(&lr_lbnat_rec->lb_ips->ips_v4_reachable,
>> +                             ip_address);
>> +                    break;
>> +                }
>> +            }
>> +        }
>> +    }
>> +
>> +    SSET_FOR_EACH (ip_address, lb_ips_v6) {
>> +        struct ovn_port *op;
>> +        struct in6_addr vip;
>> +        if (ipv6_parse(ip_address, &vip)) {
>> +            HMAP_FOR_EACH (op, dp_node, &lr_lbnat_rec->od->ports) {
>> +                if (lrouter_port_ipv6_reachable(op, &vip)) {
>> +                    sset_add(&lr_lbnat_rec->lb_ips->ips_v6_reachable,
>> +                             ip_address);
>> +                    break;
>> +                }
>> +            }
>> +        }
>> +    }
>> +}
>> +
>> +static void
>> +remove_lrouter_lb_reachable_ips(struct lr_lb_nat_data_record *lr_lbnat_rec,
>> +                                enum lb_neighbor_responder_mode neigh_mode,
>> +                                const struct sset *lb_ips_v4,
>> +                                const struct sset *lb_ips_v6)
>> +{
>> +    if (neigh_mode == LB_NEIGH_RESPOND_NONE) {
>> +        return;
>> +    }
>> +
>> +    const char *ip_address;
>> +    SSET_FOR_EACH (ip_address, lb_ips_v4) {
>> +        sset_find_and_delete(&lr_lbnat_rec->lb_ips->ips_v4_reachable,
>> +                             ip_address);
>> +    }
>> +    SSET_FOR_EACH (ip_address, lb_ips_v6) {
>> +        sset_find_and_delete(&lr_lbnat_rec->lb_ips->ips_v6_reachable,
>> +                             ip_address);
>> +    }
>> +}
>> +
>> +static void
>> +lr_lb_nat_data_build_vip_nats(struct lr_lb_nat_data_record *lr_lbnat_rec)
>> +{
>> +    sset_clear(&lr_lbnat_rec->vip_nats);
>> +    const char *external_ip;
>> +    SSET_FOR_EACH (external_ip, &lr_lbnat_rec->lrnat_rec->external_ips) {
>> +        bool is_vip_nat = false;
>> +        if (addr_is_ipv6(external_ip)) {
>> +            is_vip_nat = sset_contains(&lr_lbnat_rec->lb_ips->ips_v6,
>> +                                       external_ip);
>> +        } else {
>> +            is_vip_nat = sset_contains(&lr_lbnat_rec->lb_ips->ips_v4,
>> +                                       external_ip);
>> +        }
>> +
>> +        if (is_vip_nat) {
>> +            sset_add(&lr_lbnat_rec->vip_nats, external_ip);
>> +        }
>> +    }
>> +}
>> diff --git a/northd/en-lr-lb-nat-data.h b/northd/en-lr-lb-nat-data.h
>> new file mode 100644
>> index 0000000000..9029aee339
>> --- /dev/null
>> +++ b/northd/en-lr-lb-nat-data.h
>> @@ -0,0 +1,93 @@
>> +/*
>> + * Copyright (c) 2023, Red Hat, Inc.
>> + *
>> + * Licensed under the Apache License, Version 2.0 (the "License");
>> + * you may not use this file except in compliance with the License.
>> + * You may obtain a copy of the License at:
>> + *
>> + *     http://www.apache.org/licenses/LICENSE-2.0
>> + *
>> + * Unless required by applicable law or agreed to in writing, software
>> + * distributed under the License is distributed on an "AS IS" BASIS,
>> + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
>> + * See the License for the specific language governing permissions and
>> + * limitations under the License.
>> + */
>> +#ifndef EN_LR_LB_NAT_DATA_H
>> +#define EN_LR_LB_NAT_DATA_H 1
>> +
>> +#include <stdint.h>
>> +
>> +/* OVS includes. */
>> +#include "lib/hmapx.h"
>> +#include "openvswitch/hmap.h"
>> +#include "sset.h"
>> +
>> +/* OVN includes. */
>> +#include "lib/inc-proc-eng.h"
>> +#include "lib/lb.h"
>> +#include "lib/ovn-nb-idl.h"
>> +#include "lib/ovn-sb-idl.h"
>> +#include "lib/ovn-util.h"
>> +
>> +struct ovn_datapath;
>> +struct lr_nat_record;
>> +
>> +struct lr_lb_nat_data_record {
>> +    struct hmap_node key_node; /* Index on 'nbr->header_.uuid'. */
>> +
>> +    const struct ovn_datapath *od;
>> +    const struct lr_nat_record *lrnat_rec;
>> +
>> +    /* Load Balancer vIPs relevant for this datapath. */
>> +    struct ovn_lb_ip_set *lb_ips;
>> +
>> +    /* sset of vips which are also part of lr nats. */
>> +    struct sset vip_nats;
>> +};
>> +
>> +struct lr_lb_nat_data_table {
>> +    struct hmap entries;
>> +
>> +    /* The array index of each element in 'entries'. */
>> +    struct lr_lb_nat_data_record **array;
>> +};
>> +
>> +#define LR_LB_NAT_DATA_TABLE_FOR_EACH(LR_LB_NAT_REC, TABLE) \
>> +    HMAP_FOR_EACH (LR_LB_NAT_REC, key_node, &(TABLE)->entries)
>> +
>> +struct lr_lb_nat_data_tracked_data {
>> +    /* Created or updated logical router with LB data. */
>> +    struct hmapx crupdated; /* Stores 'struct lr_lb_nat_data_record'. */
>> +
>> +    /* Deleted logical router with LB data. */
>> +    struct hmapx deleted; /* Stores 'struct lr_lb_nat_data_record'. */
>> +};
>> +
>> +struct ed_type_lr_lb_nat_data {
>> +    struct lr_lb_nat_data_table lr_lbnats;
>> +
>> +    bool tracked;
>> +    struct lr_lb_nat_data_tracked_data tracked_data;
> 
> Same comment about 'tracked' as in the previous commit, we can probably
> remove it.
> 
> Which brings me to the following question, we don't really use
> lr_lb_nat_data_tracked_data->deleted anywhere; we never add anything to
> it.  Is it on purpose, should we just delete it?  Or is it a bug?
> 
> Thanks,
> Dumitru
> 
>> +};
>> +
>> +struct lr_lb_nat_data_input {
>> +    const struct ovn_datapaths *lr_datapaths;
>> +    const struct hmap *lb_datapaths_map;
>> +    const struct hmap *lbgrp_datapaths_map;
>> +    const struct lr_nat_table *lr_nats;
>> +};
>> +
>> +void *en_lr_lb_nat_data_init(struct engine_node *, struct engine_arg *);
>> +void en_lr_lb_nat_data_cleanup(void *data);
>> +void en_lr_lb_nat_data_clear_tracked_data(void *data);
>> +void en_lr_lb_nat_data_run(struct engine_node *, void *data);
>> +
>> +bool lr_lb_nat_data_northd_handler(struct engine_node *, void *data);
>> +bool lr_lb_nat_data_lr_nat_handler(struct engine_node *, void *data);
>> +bool lr_lb_nat_data_lb_data_handler(struct engine_node *, void *data);
>> +
>> +const struct lr_lb_nat_data_record *lr_lb_nat_data_table_find_by_index(
>> +    const struct lr_lb_nat_data_table *, size_t od_index);
>> +
>> +#endif /* EN_LR_LB_NAT_DATA_H */
>> \ No newline at end of file

No newline at end of file.

>> diff --git a/northd/en-lr-nat.h b/northd/en-lr-nat.h
>> index 01a16a21aa..2e3f285d12 100644
>> --- a/northd/en-lr-nat.h
>> +++ b/northd/en-lr-nat.h
>> @@ -89,6 +89,9 @@ struct lr_nat_table {
>>  const struct lr_nat_record * lr_nat_table_find_by_index(
>>      const struct lr_nat_table *, size_t od_index);
>>  
>> +#define LR_NAT_TABLE_FOR_EACH(LR_NAT_REC, TABLE) \
>> +    HMAP_FOR_EACH (LR_NAT_REC, key_node, &(TABLE)->entries)
>> +
>>  /* Incremental processing implementation. */
>>  struct lr_nat_input {
>>      /* Northbound table references. */
>> diff --git a/northd/en-sync-sb.c b/northd/en-sync-sb.c
>> index 10ade620e7..7c22949f74 100644
>> --- a/northd/en-sync-sb.c
>> +++ b/northd/en-sync-sb.c
>> @@ -22,6 +22,7 @@
>>  #include "openvswitch/util.h"
>>  
>>  #include "en-lr-nat.h"
>> +#include "en-lr-lb-nat-data.h"
>>  #include "en-sync-sb.h"
>>  #include "lib/inc-proc-eng.h"
>>  #include "lib/lb.h"
>> @@ -41,7 +42,7 @@ static void sync_addr_sets(struct ovsdb_idl_txn *ovnsb_txn,
>>                             const struct nbrec_address_set_table *,
>>                             const struct nbrec_port_group_table *,
>>                             const struct sbrec_address_set_table *,
>> -                           const struct ovn_datapaths *lr_datapaths);
>> +                           const struct lr_lb_nat_data_table *);
>>  static const struct sbrec_address_set *sb_address_set_lookup_by_name(
>>      struct ovsdb_idl_index *, const char *name);
>>  static void update_sb_addr_set(struct sorted_array *,
>> @@ -87,11 +88,11 @@ en_sync_to_sb_addr_set_run(struct engine_node *node, void *data OVS_UNUSED)
>>          EN_OVSDB_GET(engine_get_input("SB_address_set", node));
>>  
>>      const struct engine_context *eng_ctx = engine_get_context();
>> -    struct northd_data *northd_data = engine_get_input_data("northd", node);
>> -
>> +    const struct ed_type_lr_lb_nat_data *lr_lb_nat_data =
>> +        engine_get_input_data("lr_lb_nat_data", node);
>>      sync_addr_sets(eng_ctx->ovnsb_idl_txn, nb_address_set_table,
>>                     nb_port_group_table, sb_address_set_table,
>> -                   &northd_data->lr_datapaths);
>> +                   &lr_lb_nat_data->lr_lbnats);
>>  
>>      engine_set_node_state(node, EN_UPDATED);
>>  }
>> @@ -288,10 +289,12 @@ en_sync_to_sb_pb_run(struct engine_node *node, void *data OVS_UNUSED)
>>  {
>>      const struct engine_context *eng_ctx = engine_get_context();
>>      struct northd_data *northd_data = engine_get_input_data("northd", node);
>> -    struct ed_type_lr_nat_data *lr_nat_data =
>> -        engine_get_input_data("lr_nat", node);
>> +    struct ed_type_lr_lb_nat_data *lr_lb_nat_data =
>> +        engine_get_input_data("lr_lb_nat_data", node);
>> +
>>      sync_pbs(eng_ctx->ovnsb_idl_txn, &northd_data->ls_ports,
>> -             &northd_data->lr_ports, &lr_nat_data->lr_nats);
>> +             &northd_data->lr_ports,
>> +             &lr_lb_nat_data->lr_lbnats);
>>      engine_set_node_state(node, EN_UPDATED);
>>  }
>>  
>> @@ -316,11 +319,12 @@ sync_to_sb_pb_northd_handler(struct engine_node *node, void *data OVS_UNUSED)
>>          return false;
>>      }
>>  
>> -    struct ed_type_lr_nat_data *lr_nat_data =
>> -        engine_get_input_data("lr_nat", node);
>> +    struct ed_type_lr_lb_nat_data *lr_lb_nat_data =
>> +        engine_get_input_data("lr_lb_nat_data", node);
>>  
>>      if (!sync_pbs_for_northd_changed_ovn_ports(
>> -            &nd->trk_northd_changes.trk_ovn_ports, &lr_nat_data->lr_nats)) {
>> +            &nd->trk_northd_changes.trk_ovn_ports,
>> +            &lr_lb_nat_data->lr_lbnats)) {
>>          return false;
>>      }
>>  
>> @@ -366,7 +370,7 @@ sync_addr_sets(struct ovsdb_idl_txn *ovnsb_txn,
>>                 const struct nbrec_address_set_table *nb_address_set_table,
>>                 const struct nbrec_port_group_table *nb_port_group_table,
>>                 const struct sbrec_address_set_table *sb_address_set_table,
>> -               const struct ovn_datapaths *lr_datapaths)
>> +               const struct lr_lb_nat_data_table *lr_lbnats)
>>  {
>>      struct shash sb_address_sets = SHASH_INITIALIZER(&sb_address_sets);
>>  
>> @@ -410,16 +414,14 @@ sync_addr_sets(struct ovsdb_idl_txn *ovnsb_txn,
>>      }
>>  
>>      /* Sync router load balancer VIP generated address sets. */
>> -    struct ovn_datapath *od;
>> -    HMAP_FOR_EACH (od, key_node, &lr_datapaths->datapaths) {
>> -        ovs_assert(od->nbr);
>> -
>> -        if (sset_count(&od->lb_ips->ips_v4_reachable)) {
>> -            char *ipv4_addrs_name = lr_lb_address_set_name(od->tunnel_key,
>> -                                                           AF_INET);
>> +    const struct lr_lb_nat_data_record *lrlb_rec;
>> +    LR_LB_NAT_DATA_TABLE_FOR_EACH (lrlb_rec, lr_lbnats) {
>> +        if (sset_count(&lrlb_rec->lb_ips->ips_v4_reachable)) {
>> +            char *ipv4_addrs_name =
>> +                lr_lb_address_set_name(lrlb_rec->od->tunnel_key, AF_INET);
>>  
>>              struct sorted_array ipv4_addrs_sorted =
>> -                    sorted_array_from_sset(&od->lb_ips->ips_v4_reachable);
>> +                sorted_array_from_sset(&lrlb_rec->lb_ips->ips_v4_reachable);
>>  
>>              sync_addr_set(ovnsb_txn, ipv4_addrs_name,
>>                            &ipv4_addrs_sorted, &sb_address_sets);
>> @@ -427,11 +429,11 @@ sync_addr_sets(struct ovsdb_idl_txn *ovnsb_txn,
>>              free(ipv4_addrs_name);
>>          }
>>  
>> -        if (sset_count(&od->lb_ips->ips_v6_reachable)) {
>> -            char *ipv6_addrs_name = lr_lb_address_set_name(od->tunnel_key,
>> -                                                           AF_INET6);
>> -            struct sorted_array ipv6_addrs_sorted =
>> -                    sorted_array_from_sset(&od->lb_ips->ips_v6_reachable);
>> +        if (sset_count(&lrlb_rec->lb_ips->ips_v6_reachable)) {
>> +            char *ipv6_addrs_name =
>> +                lr_lb_address_set_name(lrlb_rec->od->tunnel_key, AF_INET6);
>> +            struct sorted_array ipv6_addrs_sorted = sorted_array_from_sset(
>> +                &lrlb_rec->lb_ips->ips_v6_reachable);
>>  
>>              sync_addr_set(ovnsb_txn, ipv6_addrs_name,
>>                            &ipv6_addrs_sorted, &sb_address_sets);
>> diff --git a/northd/inc-proc-northd.c b/northd/inc-proc-northd.c
>> index 2bd66b8808..369a151fa3 100644
>> --- a/northd/inc-proc-northd.c
>> +++ b/northd/inc-proc-northd.c
>> @@ -31,6 +31,7 @@
>>  #include "openvswitch/vlog.h"
>>  #include "inc-proc-northd.h"
>>  #include "en-lb-data.h"
>> +#include "en-lr-lb-nat-data.h"
>>  #include "en-lr-nat.h"
>>  #include "en-northd.h"
>>  #include "en-lflow.h"
>> @@ -148,6 +149,7 @@ static ENGINE_NODE(sync_to_sb_lb, "sync_to_sb_lb");
>>  static ENGINE_NODE(sync_to_sb_pb, "sync_to_sb_pb");
>>  static ENGINE_NODE_WITH_CLEAR_TRACK_DATA(lb_data, "lb_data");
>>  static ENGINE_NODE_WITH_CLEAR_TRACK_DATA(lr_nat, "lr_nat");
>> +static ENGINE_NODE_WITH_CLEAR_TRACK_DATA(lr_lb_nat_data, "lr_lb_nat_data");
>>  
>>  void inc_proc_northd_init(struct ovsdb_idl_loop *nb,
>>                            struct ovsdb_idl_loop *sb)
>> @@ -196,6 +198,13 @@ void inc_proc_northd_init(struct ovsdb_idl_loop *nb,
>>      engine_add_input(&en_lr_nat, &en_nb_logical_router,
>>                       lr_nat_logical_router_handler);
>>  
>> +    engine_add_input(&en_lr_lb_nat_data, &en_northd,
>> +                     lr_lb_nat_data_northd_handler);
>> +    engine_add_input(&en_lr_lb_nat_data, &en_lr_nat,
>> +                     lr_lb_nat_data_lr_nat_handler);
>> +    engine_add_input(&en_lr_lb_nat_data, &en_lb_data,
>> +                     lr_lb_nat_data_lb_data_handler);
>> +
>>      engine_add_input(&en_mac_binding_aging, &en_nb_nb_global, NULL);
>>      engine_add_input(&en_mac_binding_aging, &en_sb_mac_binding, NULL);
>>      engine_add_input(&en_mac_binding_aging, &en_northd, NULL);
>> @@ -220,12 +229,14 @@ void inc_proc_northd_init(struct ovsdb_idl_loop *nb,
>>      engine_add_input(&en_lflow, &en_northd, lflow_northd_handler);
>>      engine_add_input(&en_lflow, &en_port_group, lflow_port_group_handler);
>>      engine_add_input(&en_lflow, &en_lr_nat, NULL);
>> +    engine_add_input(&en_lflow, &en_lr_lb_nat_data, NULL);
>>  
>>      engine_add_input(&en_sync_to_sb_addr_set, &en_nb_address_set,
>>                       sync_to_sb_addr_set_nb_address_set_handler);
>>      engine_add_input(&en_sync_to_sb_addr_set, &en_nb_port_group,
>>                       sync_to_sb_addr_set_nb_port_group_handler);
>>      engine_add_input(&en_sync_to_sb_addr_set, &en_northd, NULL);
>> +    engine_add_input(&en_sync_to_sb_addr_set, &en_lr_lb_nat_data, NULL);
>>      engine_add_input(&en_sync_to_sb_addr_set, &en_sb_address_set, NULL);
>>  
>>      engine_add_input(&en_port_group, &en_nb_port_group,
>> @@ -243,7 +254,7 @@ void inc_proc_northd_init(struct ovsdb_idl_loop *nb,
>>  
>>      engine_add_input(&en_sync_to_sb_pb, &en_northd,
>>                       sync_to_sb_pb_northd_handler);
>> -    engine_add_input(&en_sync_to_sb_pb, &en_lr_nat, NULL);
>> +    engine_add_input(&en_sync_to_sb_pb, &en_lr_lb_nat_data, NULL);
>>  
>>      /* en_sync_to_sb engine node syncs the SB database tables from
>>       * the NB database tables.
>> diff --git a/northd/northd.c b/northd/northd.c
>> index 44c9c3d729..24df14c0de 100644
>> --- a/northd/northd.c
>> +++ b/northd/northd.c
>> @@ -44,6 +44,7 @@
>>  #include "northd.h"
>>  #include "en-lb-data.h"
>>  #include "en-lr-nat.h"
>> +#include "en-lr-lb-nat-data.h"
>>  #include "lib/ovn-parallel-hmap.h"
>>  #include "ovn/actions.h"
>>  #include "ovn/features.h"
>> @@ -617,13 +618,6 @@ init_lb_for_datapath(struct ovn_datapath *od)
>>      }
>>  }
>>  
>> -static void
>> -destroy_lb_for_datapath(struct ovn_datapath *od)
>> -{
>> -    ovn_lb_ip_set_destroy(od->lb_ips);
>> -    od->lb_ips = NULL;
>> -}
>> -
>>  /* A group of logical router datapaths which are connected - either
>>   * directly or indirectly.
>>   * Each logical router can belong to only one group. */
>> @@ -676,7 +670,6 @@ ovn_datapath_destroy(struct hmap *datapaths, struct ovn_datapath *od)
>>          destroy_ipam_info(&od->ipam_info);
>>          free(od->router_ports);
>>          free(od->ls_peers);
>> -        destroy_lb_for_datapath(od);
>>          free(od->localnet_ports);
>>          free(od->l3dgw_ports);
>>          destroy_mcast_info_for_datapath(od);
>> @@ -1311,121 +1304,6 @@ struct lflow_ref_node {
>>      struct ovn_lflow *lflow;
>>  };
>>  
>> -/* A logical switch port or logical router port.
>> - *
>> - * In steady state, an ovn_port points to a northbound Logical_Switch_Port
>> - * record (via 'nbsp') *or* a Logical_Router_Port record (via 'nbrp'), and to a
>> - * southbound Port_Binding record (via 'sb').  As the state of the system
>> - * changes, join_logical_ports() may determine that there is a new LSP or LRP
>> - * that has no corresponding Port_Binding record (in which case build_ports())
>> - * will create the missing Port_Binding) or that a Port_Binding record exists
>> - * that has no coresponding LSP (in which case build_ports() will delete the
>> - * spurious Port_Binding).  Thus, after build_ports() runs, any given ovn_port
>> - * will have 'sb' nonnull, and 'nbsp' xor 'nbrp' nonnull.
>> - *
>> - * Ordinarily there is only one ovn_port that points to a given LSP or LRP (but
>> - * distributed gateway ports point a "derived" ovn_port to a duplicate LRP).
>> - */
>> -struct ovn_port {
>> -    /* Port name aka key.
>> -     *
>> -     * This is ordinarily the same as nbsp->name or nbrp->name and
>> -     * sb->logical_port.  (A distributed gateway port creates a "derived"
>> -     * ovn_port with key "cr-%s" % nbrp->name.) */
>> -    struct hmap_node key_node;  /* Index on 'key'. */
>> -    char *key;                  /* nbsp->name, nbrp->name, sb->logical_port. */
>> -    char *json_key;             /* 'key', quoted for use in JSON. */
>> -
>> -    const struct sbrec_port_binding *sb;         /* May be NULL. */
>> -
>> -    uint32_t tunnel_key;
>> -
>> -    /* Logical switch port data. */
>> -    const struct nbrec_logical_switch_port *nbsp; /* May be NULL. */
>> -
>> -    struct lport_addresses *lsp_addrs;  /* Logical switch port addresses. */
>> -    unsigned int n_lsp_addrs;  /* Total length of lsp_addrs. */
>> -    unsigned int n_lsp_non_router_addrs; /* Number of elements from the
>> -                                          * beginning of 'lsp_addrs' extracted
>> -                                          * directly from LSP 'addresses'. */
>> -
>> -    struct lport_addresses *ps_addrs;   /* Port security addresses. */
>> -    unsigned int n_ps_addrs;
>> -
>> -    bool lsp_can_be_inc_processed; /* If it can be incrementally processed when
>> -                                      the port changes. */
>> -
>> -    /* Logical router port data. */
>> -    const struct nbrec_logical_router_port *nbrp; /* May be NULL. */
>> -
>> -    struct lport_addresses lrp_networks;
>> -
>> -    struct ovn_port_routable_addresses routables;
>> -
>> -    /* Logical port multicast data. */
>> -    struct mcast_port_info mcast_info;
>> -
>> -    /* At most one of l3dgw_port and cr_port can be not NULL. */
>> -
>> -    /* This is set to a distributed gateway port if and only if this ovn_port
>> -     * is "derived" from it. Otherwise this is set to NULL. The derived
>> -     * ovn_port represents the instance of distributed gateway port on the
>> -     * gateway chassis.*/
>> -    struct ovn_port *l3dgw_port;
>> -
>> -    /* This is set to the "derived" chassis-redirect port of this port if and
>> -     * only if this port is a distributed gateway port. Otherwise this is set
>> -     * to NULL. */
>> -    struct ovn_port *cr_port;
>> -
>> -    bool has_unknown; /* If the addresses have 'unknown' defined. */
>> -
>> -    bool has_bfd;
>> -
>> -    /* The port's peer:
>> -     *
>> -     *     - A switch port S of type "router" has a router port R as a peer,
>> -     *       and R in turn has S has its peer.
>> -     *
>> -     *     - Two connected logical router ports have each other as peer.
>> -     *
>> -     *     - Other kinds of ports have no peer. */
>> -    struct ovn_port *peer;
>> -
>> -    struct ovn_datapath *od;
>> -
>> -    struct ovs_list list;       /* In list of similar records. */
>> -
>> -    struct hmap_node dp_node;   /* Node in od->ports. */
>> -
>> -    struct lport_addresses proxy_arp_addrs;
>> -
>> -    /* Temporarily used for traversing a list (or hmap) of ports. */
>> -    bool visited;
>> -
>> -    /* List of struct lflow_ref_node that points to the lflows generated by
>> -     * this ovn_port.
>> -     *
>> -     * This data is initialized and destroyed by the en_northd node, but
>> -     * populated and used only by the en_lflow node. Ideally this data should
>> -     * be maintained as part of en_lflow's data (struct lflow_data): a hash
>> -     * index from ovn_port key to lflows.  However, it would be less efficient
>> -     * and more complex:
>> -     *
>> -     * 1. It would require an extra search (using the index) to find the
>> -     * lflows.
>> -     *
>> -     * 2. Building the index needs to be thread-safe, using either a global
>> -     * lock which is obviously less efficient, or hash-based lock array which
>> -     * is more complex.
>> -     *
>> -     * Adding the list here is more straightforward. The drawback is that we
>> -     * need to keep in mind that this data belongs to en_lflow node, so never
>> -     * access it from any other nodes.
>> -     */
>> -    struct ovs_list lflows;
>> -};
>> -
>>  static bool lsp_can_be_inc_processed(const struct nbrec_logical_switch_port *);
>>  
>>  static bool
>> @@ -1450,16 +1328,21 @@ destroy_routable_addresses(struct ovn_port_routable_addresses *ra)
>>  }
>>  
>>  static char **get_nat_addresses(const struct ovn_port *op, size_t *n,
>> -                                bool routable_only, bool include_lb_ips);
>> +                                bool routable_only, bool include_lb_ips,
>> +                                const struct lr_lb_nat_data_record *);
>>  
>> -static void
>> -assign_routable_addresses(struct ovn_port *op)
>> +static struct ovn_port_routable_addresses
>> +get_op_routable_addresses(struct ovn_port *op,
>> +                          const struct lr_lb_nat_data_record *lr_lbnat_rec)
>>  {
>>      size_t n;
>> -    char **nats = get_nat_addresses(op, &n, true, true);
>> +    char **nats = get_nat_addresses(op, &n, true, true, lr_lbnat_rec);
>>  
>>      if (!nats) {
>> -        return;
>> +        return (struct ovn_port_routable_addresses) {
>> +            .laddrs = NULL,
>> +            .n_addrs = 0,
>> +        };
>>      }
>>  
>>      struct lport_addresses *laddrs = xcalloc(n, sizeof(*laddrs));
>> @@ -1475,9 +1358,15 @@ assign_routable_addresses(struct ovn_port *op)
>>      }
>>      free(nats);
>>  
>> -    /* Everything seems to have worked out */
>> -    op->routables.laddrs = laddrs;
>> -    op->routables.n_addrs = n_addrs;
>> +    if (!n_addrs) {
>> +        free(laddrs);
>> +        laddrs = NULL;
>> +    }
>> +
>> +    return (struct ovn_port_routable_addresses) {
>> +        .laddrs = laddrs,
>> +        .n_addrs = n_addrs,
>> +    };
>>  }
>>  
>>  
>> @@ -1537,8 +1426,6 @@ ovn_port_destroy_orphan(struct ovn_port *port)
>>      }
>>      free(port->ps_addrs);
>>  
>> -    destroy_routable_addresses(&port->routables);
>> -
>>      destroy_lport_addresses(&port->lrp_networks);
>>      destroy_lport_addresses(&port->proxy_arp_addrs);
>>      free(port->json_key);
>> @@ -2580,9 +2467,7 @@ join_logical_ports(const struct sbrec_port_binding_table *sbrec_pb_table,
>>                                                   sizeof *od->l3dgw_ports);
>>                  }
>>                  od->l3dgw_ports[od->n_l3dgw_ports++] = op;
>> -
>> -                assign_routable_addresses(op);
>> -            }
>> +           }
>>          }
>>      }
>>  
>> @@ -2679,7 +2564,8 @@ join_logical_ports(const struct sbrec_port_binding_table *sbrec_pb_table,
>>   * and must free the returned array when it is no longer needed. */
>>  static char **
>>  get_nat_addresses(const struct ovn_port *op, size_t *n, bool routable_only,
>> -                  bool include_lb_ips)
>> +                  bool include_lb_ips,
>> +                  const struct lr_lb_nat_data_record *lr_lbnat_rec)
>>  {
>>      size_t n_nats = 0;
>>      struct eth_addr mac;
>> @@ -2764,23 +2650,25 @@ get_nat_addresses(const struct ovn_port *op, size_t *n, bool routable_only,
>>          }
>>      }
>>  
>> -    if (include_lb_ips) {
>> +    if (include_lb_ips && lr_lbnat_rec) {
>>          const char *ip_address;
>>          if (routable_only) {
>> -            SSET_FOR_EACH (ip_address, &op->od->lb_ips->ips_v4_routable) {
>> +            SSET_FOR_EACH (ip_address,
>> +                           &lr_lbnat_rec->lb_ips->ips_v4_routable) {
>>                  ds_put_format(&c_addresses, " %s", ip_address);
>>                  central_ip_address = true;
>>              }
>> -            SSET_FOR_EACH (ip_address, &op->od->lb_ips->ips_v6_routable) {
>> +            SSET_FOR_EACH (ip_address,
>> +                           &lr_lbnat_rec->lb_ips->ips_v6_routable) {
>>                  ds_put_format(&c_addresses, " %s", ip_address);
>>                  central_ip_address = true;
>>              }
>>          } else {
>> -            SSET_FOR_EACH (ip_address, &op->od->lb_ips->ips_v4) {
>> +            SSET_FOR_EACH (ip_address, &lr_lbnat_rec->lb_ips->ips_v4) {
>>                  ds_put_format(&c_addresses, " %s", ip_address);
>>                  central_ip_address = true;
>>              }
>> -            SSET_FOR_EACH (ip_address, &op->od->lb_ips->ips_v6) {
>> +            SSET_FOR_EACH (ip_address, &lr_lbnat_rec->lb_ips->ips_v6) {
>>                  ds_put_format(&c_addresses, " %s", ip_address);
>>                  central_ip_address = true;
>>              }
>> @@ -3851,21 +3739,8 @@ build_lb_datapaths(const struct hmap *lbs, const struct hmap *lb_groups,
>>      HMAP_FOR_EACH (od, key_node, &lr_datapaths->datapaths) {
>>          ovs_assert(od->nbr);
>>  
>> -        /* Checking load balancer groups first, starting from the largest one,
>> -         * to more efficiently copy IP sets. */
>> -        size_t largest_group = 0;
>> -
>> -        for (size_t i = 1; i < od->nbr->n_load_balancer_group; i++) {
>> -            if (od->nbr->load_balancer_group[i]->n_load_balancer >
>> -                od->nbr->load_balancer_group[largest_group]->n_load_balancer) {
>> -                largest_group = i;
>> -            }
>> -        }
>> -
>>          for (size_t i = 0; i < od->nbr->n_load_balancer_group; i++) {
>> -            size_t idx = (i + largest_group) % od->nbr->n_load_balancer_group;
>> -
>> -            nbrec_lb_group = od->nbr->load_balancer_group[idx];
>> +            nbrec_lb_group = od->nbr->load_balancer_group[i];
>>              const struct uuid *lb_group_uuid = &nbrec_lb_group->header_.uuid;
>>  
>>              lb_group_dps =
>> @@ -3873,20 +3748,6 @@ build_lb_datapaths(const struct hmap *lbs, const struct hmap *lb_groups,
>>                                              lb_group_uuid);
>>              ovs_assert(lb_group_dps);
>>              ovn_lb_group_datapaths_add_lr(lb_group_dps, od);
>> -
>> -            if (!od->lb_ips) {
>> -                od->lb_ips =
>> -                    ovn_lb_ip_set_clone(lb_group_dps->lb_group->lb_ips);
>> -            } else {
>> -                for (size_t j = 0; j < lb_group_dps->lb_group->n_lbs; j++) {
>> -                    build_lrouter_lb_ips(od->lb_ips,
>> -                                         lb_group_dps->lb_group->lbs[j]);
>> -                }
>> -            }
>> -        }
>> -
>> -        if (!od->lb_ips) {
>> -            od->lb_ips = ovn_lb_ip_set_create();
>>          }
>>  
>>          for (size_t i = 0; i < od->nbr->n_load_balancer; i++) {
>> @@ -3895,7 +3756,6 @@ build_lb_datapaths(const struct hmap *lbs, const struct hmap *lb_groups,
>>              lb_dps = ovn_lb_datapaths_find(lb_datapaths_map, lb_uuid);
>>              ovs_assert(lb_dps);
>>              ovn_lb_datapaths_add_lr(lb_dps, 1, &od);
>> -            build_lrouter_lb_ips(od->lb_ips, lb_dps->lb);
>>          }
>>      }
>>  
>> @@ -3949,102 +3809,6 @@ build_lb_svcs(
>>      }
>>  }
>>  
>> -static bool lrouter_port_ipv4_reachable(const struct ovn_port *op,
>> -                                        ovs_be32 addr);
>> -static bool lrouter_port_ipv6_reachable(const struct ovn_port *op,
>> -                                        const struct in6_addr *addr);
>> -
>> -static void
>> -add_neigh_ips_to_lrouter(struct ovn_datapath *od,
>> -                         enum lb_neighbor_responder_mode neigh_mode,
>> -                         const struct sset *lb_ips_v4,
>> -                         const struct sset *lb_ips_v6)
>> -{
>> -    /* If configured to not reply to any neighbor requests for all VIPs
>> -     * return early.
>> -     */
>> -    if (neigh_mode == LB_NEIGH_RESPOND_NONE) {
>> -        return;
>> -    }
>> -
>> -    const char *ip_address;
>> -
>> -    /* If configured to reply to neighbor requests for all VIPs force them
>> -     * all to be considered "reachable".
>> -     */
>> -    if (neigh_mode == LB_NEIGH_RESPOND_ALL) {
>> -        SSET_FOR_EACH (ip_address, lb_ips_v4) {
>> -            sset_add(&od->lb_ips->ips_v4_reachable, ip_address);
>> -        }
>> -        SSET_FOR_EACH (ip_address, lb_ips_v6) {
>> -            sset_add(&od->lb_ips->ips_v6_reachable, ip_address);
>> -        }
>> -
>> -        return;
>> -    }
>> -
>> -    /* Otherwise, a VIP is reachable if there's at least one router
>> -     * subnet that includes it.
>> -     */
>> -    ovs_assert(neigh_mode == LB_NEIGH_RESPOND_REACHABLE);
>> -
>> -    SSET_FOR_EACH (ip_address, lb_ips_v4) {
>> -        struct ovn_port *op;
>> -        ovs_be32 vip_ip4;
>> -        if (ip_parse(ip_address, &vip_ip4)) {
>> -            HMAP_FOR_EACH (op, dp_node, &od->ports) {
>> -                if (lrouter_port_ipv4_reachable(op, vip_ip4)) {
>> -                    sset_add(&od->lb_ips->ips_v4_reachable,
>> -                             ip_address);
>> -                    break;
>> -                }
>> -            }
>> -        }
>> -    }
>> -
>> -    SSET_FOR_EACH (ip_address, lb_ips_v6) {
>> -        struct ovn_port *op;
>> -        struct in6_addr vip;
>> -        if (ipv6_parse(ip_address, &vip)) {
>> -            HMAP_FOR_EACH (op, dp_node, &od->ports) {
>> -                if (lrouter_port_ipv6_reachable(op, &vip)) {
>> -                    sset_add(&od->lb_ips->ips_v6_reachable,
>> -                             ip_address);
>> -                    break;
>> -                }
>> -            }
>> -        }
>> -    }
>> -}
>> -
>> -static void
>> -remove_lrouter_lb_reachable_ips(struct ovn_datapath *od,
>> -                                enum lb_neighbor_responder_mode neigh_mode,
>> -                                const struct sset *lb_ips_v4,
>> -                                const struct sset *lb_ips_v6)
>> -{
>> -    if (neigh_mode == LB_NEIGH_RESPOND_NONE) {
>> -        return;
>> -    }
>> -
>> -    const char *ip_address;
>> -    SSET_FOR_EACH (ip_address, lb_ips_v4) {
>> -        sset_find_and_delete(&od->lb_ips->ips_v4_reachable, ip_address);
>> -    }
>> -    SSET_FOR_EACH (ip_address, lb_ips_v6) {
>> -        sset_find_and_delete(&od->lb_ips->ips_v6_reachable, ip_address);
>> -    }
>> -}
>> -
>> -static void
>> -build_lrouter_lb_reachable_ips(struct ovn_datapath *od,
>> -                               const struct ovn_northd_lb *lb)
>> -{
>> -    add_neigh_ips_to_lrouter(od, lb->neigh_mode, &lb->ips_v4,
>> -                             &lb->ips_v6);
>> -}
>> -
>> -
>>  static void
>>  build_lrouter_lbs_check(const struct ovn_datapaths *lr_datapaths)
>>  {
>> @@ -4066,43 +3830,6 @@ build_lrouter_lbs_check(const struct ovn_datapaths *lr_datapaths)
>>      }
>>  }
>>  
>> -static void
>> -build_lrouter_lbs_reachable_ips(struct ovn_datapaths *lr_datapaths,
>> -                                struct hmap *lb_dps_map,
>> -                                struct hmap *lb_group_dps_map)
>> -{
>> -    struct ovn_datapath *od;
>> -
>> -    HMAP_FOR_EACH (od, key_node, &lr_datapaths->datapaths) {
>> -        if (!od->nbr) {
>> -            continue;
>> -        }
>> -
>> -        for (size_t i = 0; i < od->nbr->n_load_balancer; i++) {
>> -            struct ovn_lb_datapaths *lb_dps =
>> -                ovn_lb_datapaths_find(lb_dps_map,
>> -                                &od->nbr->load_balancer[i]->header_.uuid);
>> -            ovs_assert(lb_dps);
>> -            build_lrouter_lb_reachable_ips(od, lb_dps->lb);
>> -        }
>> -
>> -        for (size_t i = 0; i < od->nbr->n_load_balancer_group; i++) {
>> -            const struct nbrec_load_balancer_group *nbrec_lb_group =
>> -                od->nbr->load_balancer_group[i];
>> -            struct ovn_lb_group_datapaths *lb_group_dps;
>> -
>> -            lb_group_dps =
>> -                ovn_lb_group_datapaths_find(lb_group_dps_map,
>> -                                            &nbrec_lb_group->header_.uuid);
>> -             ovs_assert(lb_group_dps);
>> -            for (size_t j = 0; j < lb_group_dps->lb_group->n_lbs; j++) {
>> -                build_lrouter_lb_reachable_ips(od,
>> -                                               lb_group_dps->lb_group->lbs[j]);
>> -            }
>> -        }
>> -    }
>> -}
>> -
>>  static void
>>  build_lswitch_lbs_from_lrouter(struct ovn_datapaths *lr_datapaths,
>>                                 struct hmap *lb_dps_map,
>> @@ -4166,8 +3893,6 @@ build_lb_port_related_data(
>>      struct hmap *svc_monitor_map)
>>  {
>>      build_lrouter_lbs_check(lr_datapaths);
>> -    build_lrouter_lbs_reachable_ips(lr_datapaths, lb_dps_map,
>> -                                    lb_group_dps_map);
>>      build_lb_svcs(ovnsb_txn, sbrec_service_monitor_table, ls_ports, lb_dps_map,
>>                    svc_monitor_lsps, svc_monitor_map);
>>      build_lswitch_lbs_from_lrouter(lr_datapaths, lb_dps_map, lb_group_dps_map);
>> @@ -4533,7 +4258,8 @@ check_sb_lb_duplicates(const struct sbrec_load_balancer_table *table)
>>   * Caller should make sure that the OVN SB IDL txn is not NULL.  Presently it
>>   * only syncs the nat column of port binding corresponding to the 'op->nbsp' */
>>  static void
>> -sync_pb_for_lsp(struct ovn_port *op)
>> +sync_pb_for_lsp(struct ovn_port *op,
>> +                const struct lr_lb_nat_data_table *lr_lbnats)
>>  {
>>      ovs_assert(op->nbsp);
>>  
>> @@ -4552,10 +4278,17 @@ sync_pb_for_lsp(struct ovn_port *op)
>>          if (nat_addresses && !strcmp(nat_addresses, "router")) {
>>              if (op->peer && op->peer->od
>>                  && (chassis || op->peer->od->n_l3dgw_ports)) {
>> -                bool exclude_lb_vips = smap_get_bool(&op->nbsp->options,
>> +                bool include_lb_vips = !smap_get_bool(&op->nbsp->options,
>>                          "exclude-lb-vips-from-garp", false);
>> +
>> +                const struct lr_lb_nat_data_record *lr_lbnat_rec = NULL;
>> +
>> +                if (include_lb_vips) {
>> +                    lr_lbnat_rec = lr_lb_nat_data_table_find_by_index(
>> +                        lr_lbnats, op->peer->od->index);
>> +                }
>>                  nats = get_nat_addresses(op->peer, &n_nats, false,
>> -                                            !exclude_lb_vips);
>> +                                         include_lb_vips, lr_lbnat_rec);
>>              }
>>          } else if (nat_addresses && (chassis || l3dgw_ports)) {
>>              struct lport_addresses laddrs;
>> @@ -4662,7 +4395,8 @@ sync_pb_for_lsp(struct ovn_port *op)
>>   * Caller should make sure that the OVN SB IDL txn is not NULL.  Presently it
>>   * only sets the port binding options column for the router ports */
>>  static void
>> -sync_pb_for_lrp(struct ovn_port *op, const struct lr_nat_table *lr_nats)
>> +sync_pb_for_lrp(struct ovn_port *op,
>> +                const struct lr_lb_nat_data_table *lr_lbnats)
>>  {
>>      ovs_assert(op->nbrp);
>>  
>> @@ -4671,14 +4405,14 @@ sync_pb_for_lrp(struct ovn_port *op, const struct lr_nat_table *lr_nats)
>>  
>>      const char *chassis_name = smap_get(&op->od->nbr->options, "chassis");
>>      if (is_cr_port(op)) {
>> -        const struct lr_nat_record *lrnat_rec =
>> -            lr_nat_table_find_by_index(lr_nats, op->od->index);
>> -        ovs_assert(lrnat_rec);
>> +        const struct lr_lb_nat_data_record *lr_lbnat_rec =
>> +            lr_lb_nat_data_table_find_by_index(lr_lbnats, op->od->index);
>> +        ovs_assert(lr_lbnat_rec);
>>  
>>          smap_add(&new, "distributed-port", op->nbrp->name);
>>  
>>          bool always_redirect =
>> -            !lrnat_rec->has_distributed_nat &&
>> +            !lr_lbnat_rec->lrnat_rec->has_distributed_nat &&
>>              !l3dgw_port_has_associated_vtep_lports(op->l3dgw_port);
>>  
>>          const char *redirect_type = smap_get(&op->nbrp->options,
>> @@ -4729,17 +4463,18 @@ static void ovn_update_ipv6_opt_for_op(struct ovn_port *op);
>>   * the logical switch ports. */
>>  void
>>  sync_pbs(struct ovsdb_idl_txn *ovnsb_idl_txn, struct hmap *ls_ports,
>> -         struct hmap *lr_ports, const struct lr_nat_table *lr_nats)
>> +         struct hmap *lr_ports,
>> +         const struct lr_lb_nat_data_table *lr_lbnats)
>>  {
>>      ovs_assert(ovnsb_idl_txn);
>>  
>>      struct ovn_port *op;
>>      HMAP_FOR_EACH (op, key_node, ls_ports) {
>> -        sync_pb_for_lsp(op);
>> +        sync_pb_for_lsp(op, lr_lbnats);
>>      }
>>  
>>      HMAP_FOR_EACH (op, key_node, lr_ports) {
>> -        sync_pb_for_lrp(op, lr_nats);
>> +        sync_pb_for_lrp(op, lr_lbnats);
>>      }
>>  
>>      ovn_update_ipv6_options(lr_ports);
>> @@ -4748,17 +4483,18 @@ sync_pbs(struct ovsdb_idl_txn *ovnsb_idl_txn, struct hmap *ls_ports,
>>  /* Sync the SB Port bindings for the added and updated logical switch ports
>>   * of the tracked northd engine data. */
>>  bool
>> -sync_pbs_for_northd_changed_ovn_ports(struct tracked_ovn_ports *trk_ovn_ports,
>> -                                      const struct lr_nat_table *lr_nats)
>> +sync_pbs_for_northd_changed_ovn_ports(
>> +    struct tracked_ovn_ports *trk_ovn_ports,
>> +    const struct lr_lb_nat_data_table *lr_lbnats)
>>  {
>>      struct hmapx_node *hmapx_node;
>>      struct ovn_port *op;
>>      HMAPX_FOR_EACH (hmapx_node, &trk_ovn_ports->created) {
>>          op = hmapx_node->data;
>>          if (op->nbsp) {
>> -            sync_pb_for_lsp(op);
>> +            sync_pb_for_lsp(op, lr_lbnats);
>>          } else {
>> -            sync_pb_for_lrp(op, lr_nats);
>> +            sync_pb_for_lrp(op, lr_lbnats);
>>              ovn_update_ipv6_opt_for_op(op);
>>          }
>>      }
>> @@ -4766,9 +4502,9 @@ sync_pbs_for_northd_changed_ovn_ports(struct tracked_ovn_ports *trk_ovn_ports,
>>      HMAPX_FOR_EACH (hmapx_node, &trk_ovn_ports->updated) {
>>          op = hmapx_node->data;
>>          if (op->nbsp) {
>> -            sync_pb_for_lsp(op);
>> +            sync_pb_for_lsp(op, lr_lbnats);
>>          } else {
>> -            sync_pb_for_lrp(op, lr_nats);
>> +            sync_pb_for_lrp(op, lr_lbnats);
>>              ovn_update_ipv6_opt_for_op(op);
>>          }
>>      }
>> @@ -5475,20 +5211,24 @@ fail:
>>  }
>>  
>>  /* Returns true if the logical router has changes which can be
>> - * incrementally handled.
>> + * incrementally handled or the changes can be ignored.
>>   * Presently supports i-p for the below changes:
>>   *    - load balancers and load balancer groups.
>> + *
>> + * Presently below changes are ignored:
>> + *    - router NAT changes - as the engine node lr-nat handles it.
>>   */
>>  static bool
>> -lr_changes_can_be_handled(
>> +lr_changes_can_be_handled_or_ignored(
>>      const struct nbrec_logical_router *lr)
>>  {
>>      /* Check if the columns are changed in this row. */
>>      enum nbrec_logical_router_column_id col;
>>      for (col = 0; col < NBREC_LOGICAL_ROUTER_N_COLUMNS; col++) {
>>          if (nbrec_logical_router_is_updated(lr, col)) {
>> -            if (col == NBREC_LOGICAL_ROUTER_COL_LOAD_BALANCER ||
>> -                col == NBREC_LOGICAL_ROUTER_COL_LOAD_BALANCER_GROUP) {
>> +            if (col == NBREC_LOGICAL_ROUTER_COL_LOAD_BALANCER
>> +                || col == NBREC_LOGICAL_ROUTER_COL_LOAD_BALANCER_GROUP
>> +                || col == NBREC_LOGICAL_ROUTER_COL_NAT) {
>>                  continue;
>>              }
>>              return false;
>> @@ -5507,12 +5247,6 @@ lr_changes_can_be_handled(
>>                                  OVSDB_IDL_CHANGE_MODIFY) > 0) {
>>          return false;
>>      }
>> -    for (size_t i = 0; i < lr->n_nat; i++) {
>> -        if (nbrec_nat_row_get_seqno(lr->nat[i],
>> -                                OVSDB_IDL_CHANGE_MODIFY) > 0) {
>> -            return false;
>> -        }
>> -    }
>>      for (size_t i = 0; i < lr->n_policies; i++) {
>>          if (nbrec_logical_router_policy_row_get_seqno(lr->policies[i],
>>                                  OVSDB_IDL_CHANGE_MODIFY) > 0) {
>> @@ -5528,14 +5262,15 @@ lr_changes_can_be_handled(
>>      return true;
>>  }
>>  
>> -/* Return true if changes are handled incrementally, false otherwise.
>> +/* Return true if changes are handled incrementally or can be safely
>> + * ignored (because those changes are handled by other engine nodes),
>> + * false otherwise.
>>   * When there are any changes, try to track what's exactly changed and set
>>   * northd_data->change_tracked accordingly: change tracked - true, otherwise,
>>   * false.
>>   * Note: Changes to load balancer and load balancer groups associated with
>>   * the logical routers are handled separately in the lb_data change
>> - * handlers (northd_handle_lb_data_changes_pre_od and
>> - * northd_handle_lb_data_changes_post_od).
>> + * handler (northd_handle_lb_data_changes).
>>   * */
>>  bool
>>  northd_handle_lr_changes(const struct northd_input *ni,
>> @@ -5550,9 +5285,11 @@ northd_handle_lr_changes(const struct northd_input *ni,
>>              goto fail;
>>          }
>>  
>> -        /* Presently only able to handle load balancer and
>> -         * load balancer group changes. */
>> -        if (!lr_changes_can_be_handled(changed_lr)) {
>> +        /* Presently
>> +         *   - only able to handle load balancer and load balancer group
>> +               changes.
>> +         *   - and ignore NAT changes */
>> +        if (!lr_changes_can_be_handled_or_ignored(changed_lr)) {
>>              goto fail;
>>          }
>>      }
>> @@ -5804,10 +5541,6 @@ northd_handle_lb_data_changes(struct tracked_lb_data *trk_lb_data,
>>              ovs_assert(lb_dps);
>>              ovn_lb_datapaths_add_lr(lb_dps, 1, &od);
>>  
>> -            /* Add the lb_ips of lb_dps to the od. */
>> -            build_lrouter_lb_ips(od->lb_ips, lb_dps->lb);
>> -            build_lrouter_lb_reachable_ips(od, lb_dps->lb);
>> -
>>              /* Add the lb to the northd tracked data. */
>>              hmapx_add(&nd_changes->trk_lbs.crupdated, lb_dps);
>>          }
>> @@ -5826,10 +5559,6 @@ northd_handle_lb_data_changes(struct tracked_lb_data *trk_lb_data,
>>                  ovs_assert(lb_dps);
>>                  ovn_lb_datapaths_add_lr(lb_dps, 1, &od);
>>  
>> -                /* Add the lb_ips of lb_dps to the od. */
>> -                build_lrouter_lb_ips(od->lb_ips, lb_dps->lb);
>> -                build_lrouter_lb_reachable_ips(od, lb_dps->lb);
>> -
>>                  /* Add the lb to the northd tracked data. */
>>                  hmapx_add(&nd_changes->trk_lbs.crupdated, lb_dps);
>>              }
>> @@ -5865,22 +5594,6 @@ northd_handle_lb_data_changes(struct tracked_lb_data *trk_lb_data,
>>              /* Re-evaluate 'od->has_lb_vip' */
>>              init_lb_for_datapath(od);
>>  
>> -            /* Update the od->lb_ips with the deleted and inserted
>> -             * vips (if any). */
>> -            remove_ips_from_lb_ip_set(od->lb_ips, lb->routable,
>> -                                      &clb->deleted_vips_v4,
>> -                                      &clb->deleted_vips_v6);
>> -            add_ips_to_lb_ip_set(od->lb_ips, lb->routable,
>> -                                 &clb->inserted_vips_v4,
>> -                                 &clb->inserted_vips_v6);
>> -
>> -            remove_lrouter_lb_reachable_ips(od, lb->neigh_mode,
>> -                                            &clb->deleted_vips_v4,
>> -                                            &clb->deleted_vips_v6);
>> -            add_neigh_ips_to_lrouter(od, lb->neigh_mode,
>> -                                     &clb->inserted_vips_v4,
>> -                                     &clb->inserted_vips_v6);
>> -
>>              /* Add the lr datapath to the northd tracked data. */
>>              hmapx_add(&nd_changes->lr_with_changed_lbs.crupdated, od);
>>          }
>> @@ -5908,9 +5621,6 @@ northd_handle_lb_data_changes(struct tracked_lb_data *trk_lb_data,
>>                  /* Re-evaluate 'od->has_lb_vip' */
>>                  init_lb_for_datapath(od);
>>  
>> -                /* Add the lb_ips of lb_dps to the od. */
>> -                build_lrouter_lb_ips(od->lb_ips, lb_dps->lb);
>> -
>>                  /* Add the lr datapath to the northd tracked data. */
>>                  hmapx_add(&nd_changes->lr_with_changed_lbs.crupdated, od);
>>              }
>> @@ -9202,7 +8912,7 @@ arp_nd_ns_match(const char *ips, int addr_family, struct ds *match)
>>  /* Returns 'true' if the IPv4 'addr' is on the same subnet with one of the
>>   * IPs configured on the router port.
>>   */
>> -static bool
>> +bool
>>  lrouter_port_ipv4_reachable(const struct ovn_port *op, ovs_be32 addr)
>>  {
>>      for (size_t i = 0; i < op->lrp_networks.n_ipv4_addrs; i++) {
>> @@ -9218,7 +8928,7 @@ lrouter_port_ipv4_reachable(const struct ovn_port *op, ovs_be32 addr)
>>  /* Returns 'true' if the IPv6 'addr' is on the same subnet with one of the
>>   * IPs configured on the router port.
>>   */
>> -static bool
>> +bool
>>  lrouter_port_ipv6_reachable(const struct ovn_port *op,
>>                              const struct in6_addr *addr)
>>  {
>> @@ -9284,6 +8994,7 @@ build_lswitch_rport_arp_req_flows(struct ovn_port *op,
>>                                    struct ovn_datapath *sw_od,
>>                                    struct ovn_port *sw_op,
>>                                    const struct lr_nat_table *lr_nats,
>> +                                  const struct lr_lb_nat_data_table *lr_lbnats,
>>                                    struct hmap *lflows,
>>                                    const struct ovsdb_idl_row *stage_hint)
>>  {
>> @@ -9299,32 +9010,38 @@ build_lswitch_rport_arp_req_flows(struct ovn_port *op,
>>       * router port.
>>       * Priority: 80.
>>       */
>> -
>> -    const char *ip_addr;
>> -    SSET_FOR_EACH (ip_addr, &op->od->lb_ips->ips_v4_reachable) {
>> -        ovs_be32 ipv4_addr;
>> -
>> -        /* Check if the ovn port has a network configured on which we could
>> -         * expect ARP requests for the LB VIP.
>> -         */
>> -        if (ip_parse(ip_addr, &ipv4_addr) &&
>> -            lrouter_port_ipv4_reachable(op, ipv4_addr)) {
>> -            build_lswitch_rport_arp_req_flow(
>> -                ip_addr, AF_INET, sw_op, sw_od, 80, lflows,
>> -                stage_hint);
>> +    const struct lr_lb_nat_data_record *lr_lbnat_rec = NULL;
>> +    if (op->od->nbr->n_load_balancer || op->od->nbr->n_load_balancer_group) {
>> +        lr_lbnat_rec = lr_lb_nat_data_table_find_by_index(lr_lbnats,
>> +                                                          op->od->index);
>> +        ovs_assert(lr_lbnat_rec);
>> +
>> +        const char *ip_addr;
>> +        SSET_FOR_EACH (ip_addr, &lr_lbnat_rec->lb_ips->ips_v4_reachable) {
>> +            ovs_be32 ipv4_addr;
>> +
>> +            /* Check if the ovn port has a network configured on which we could
>> +            * expect ARP requests for the LB VIP.
>> +            */
>> +            if (ip_parse(ip_addr, &ipv4_addr) &&
>> +                lrouter_port_ipv4_reachable(op, ipv4_addr)) {
>> +                build_lswitch_rport_arp_req_flow(
>> +                    ip_addr, AF_INET, sw_op, sw_od, 80, lflows,
>> +                    stage_hint);
>> +            }
>>          }
>> -    }
>> -    SSET_FOR_EACH (ip_addr, &op->od->lb_ips->ips_v6_reachable) {
>> -        struct in6_addr ipv6_addr;
>> +        SSET_FOR_EACH (ip_addr, &lr_lbnat_rec->lb_ips->ips_v6_reachable) {
>> +            struct in6_addr ipv6_addr;
>>  
>> -        /* Check if the ovn port has a network configured on which we could
>> -         * expect NS requests for the LB VIP.
>> -         */
>> -        if (ipv6_parse(ip_addr, &ipv6_addr) &&
>> -            lrouter_port_ipv6_reachable(op, &ipv6_addr)) {
>> -            build_lswitch_rport_arp_req_flow(
>> -                ip_addr, AF_INET6, sw_op, sw_od, 80, lflows,
>> -                stage_hint);
>> +            /* Check if the ovn port has a network configured on which we could
>> +            * expect NS requests for the LB VIP.
>> +            */
>> +            if (ipv6_parse(ip_addr, &ipv6_addr) &&
>> +                lrouter_port_ipv6_reachable(op, &ipv6_addr)) {
>> +                build_lswitch_rport_arp_req_flow(
>> +                    ip_addr, AF_INET6, sw_op, sw_od, 80, lflows,
>> +                    stage_hint);
>> +            }
>>          }
>>      }
>>  
>> @@ -9374,13 +9091,15 @@ build_lswitch_rport_arp_req_flows(struct ovn_port *op,
>>           * expect ARP requests/NS for the DNAT external_ip.
>>           */
>>          if (nat_entry_is_v6(nat_entry)) {
>> -            if (!sset_contains(&op->od->lb_ips->ips_v6, nat->external_ip)) {
>> +            if (!lr_lbnat_rec || !sset_contains(&lr_lbnat_rec->lb_ips->ips_v6,
>> +                                            nat->external_ip)) {
>>                  build_lswitch_rport_arp_req_flow(
>>                      nat->external_ip, AF_INET6, sw_op, sw_od, 80, lflows,
>>                      stage_hint);
>>              }
>>          } else {
>> -            if (!sset_contains(&op->od->lb_ips->ips_v4, nat->external_ip)) {
>> +            if (!lr_lbnat_rec || !sset_contains(&lr_lbnat_rec->lb_ips->ips_v4,
>> +                                            nat->external_ip)) {
>>                  build_lswitch_rport_arp_req_flow(
>>                      nat->external_ip, AF_INET, sw_op, sw_od, 80, lflows,
>>                      stage_hint);
>> @@ -10441,6 +10160,7 @@ build_lswitch_ip_mcast_igmp_mld(struct ovn_igmp_group *igmp_group,
>>  static void
>>  build_lswitch_ip_unicast_lookup(struct ovn_port *op,
>>                                  const struct lr_nat_table *lr_nats,
>> +                                const struct lr_lb_nat_data_table *lr_lbnats,
>>                                  struct hmap *lflows,
>>                                  struct ds *actions,
>>                                  struct ds *match)
>> @@ -10456,7 +10176,8 @@ build_lswitch_ip_unicast_lookup(struct ovn_port *op,
>>       */
>>      if (lsp_is_router(op->nbsp)) {
>>          build_lswitch_rport_arp_req_flows(op->peer, op->od, op, lr_nats,
>> -                                          lflows, &op->nbsp->header_);
>> +                                          lr_lbnats, lflows,
>> +                                          &op->nbsp->header_);
>>      }
>>  
>>      for (size_t i = 0; i < op->nbsp->n_addresses; i++) {
>> @@ -12646,6 +12367,7 @@ build_lrouter_port_nat_arp_nd_flow(struct ovn_port *op,
>>  static void
>>  build_lrouter_drop_own_dest(struct ovn_port *op,
>>                              const struct lr_nat_record *lrnat_rec,
>> +                            const struct lr_lb_nat_data_record *lr_lbnat_rec,
>>                              enum ovn_stage stage,
>>                              uint16_t priority, bool drop_snat_ip,
>>                              struct hmap *lflows)
>> @@ -12658,8 +12380,9 @@ build_lrouter_drop_own_dest(struct ovn_port *op,
>>  
>>              bool router_ip_in_snat_ips = !!shash_find(&lrnat_rec->snat_ips,
>>                                                        ip);
>> -            bool router_ip_in_lb_ips =
>> -                    !!sset_find(&op->od->lb_ips->ips_v4, ip);
>> +            bool router_ip_in_lb_ips = (lr_lbnat_rec &&
>> +                                    !!sset_find(&lr_lbnat_rec->lb_ips->ips_v4,
>> +                                                ip));
>>              bool drop_router_ip = (drop_snat_ip == (router_ip_in_snat_ips ||
>>                                                      router_ip_in_lb_ips));
>>  
>> @@ -12688,8 +12411,9 @@ build_lrouter_drop_own_dest(struct ovn_port *op,
>>  
>>              bool router_ip_in_snat_ips = !!shash_find(&lrnat_rec->snat_ips,
>>                                                        ip);
>> -            bool router_ip_in_lb_ips =
>> -                    !!sset_find(&op->od->lb_ips->ips_v6, ip);
>> +            bool router_ip_in_lb_ips = (lr_lbnat_rec &&
>> +                                    !!sset_find(&lr_lbnat_rec->lb_ips->ips_v6,
>> +                                                ip));
>>              bool drop_router_ip = (drop_snat_ip == (router_ip_in_snat_ips ||
>>                                                      router_ip_in_lb_ips));
>>  
>> @@ -13401,7 +13125,8 @@ build_ip_routing_flows_for_lrp(
>>   */
>>  static void
>>  build_ip_routing_flows_for_router_type_lsp(
>> -        struct ovn_port *op, const struct hmap *lr_ports, struct hmap *lflows)
>> +        struct ovn_port *op, const struct lr_lb_nat_data_table *lr_lbnats,
>> +        const struct hmap *lr_ports, struct hmap *lflows)
>>  {
>>      ovs_assert(op->nbsp);
>>      if (!lsp_is_router(op->nbsp)) {
>> @@ -13409,7 +13134,8 @@ build_ip_routing_flows_for_router_type_lsp(
>>      }
>>  
>>      struct ovn_port *peer = ovn_port_get_peer(lr_ports, op);
>> -    if (!peer || !peer->nbrp || !peer->lrp_networks.n_ipv4_addrs) {
>> +    if (!peer || !peer->nbrp || !peer->lrp_networks.n_ipv4_addrs
>> +        || !op->od->n_router_ports) {
>>          return;
>>      }
>>  
>> @@ -13420,19 +13146,29 @@ build_ip_routing_flows_for_router_type_lsp(
>>              continue;
>>          }
>>  
>> -        struct ovn_port_routable_addresses *ra = &router_port->routables;
>> -        for (size_t j = 0; j < ra->n_addrs; j++) {
>> -            struct lport_addresses *laddrs = &ra->laddrs[j];
>> -            for (size_t k = 0; k < laddrs->n_ipv4_addrs; k++) {
>> -                add_route(lflows, peer->od, peer,
>> -                          peer->lrp_networks.ipv4_addrs[0].addr_s,
>> -                          laddrs->ipv4_addrs[k].network_s,
>> -                          laddrs->ipv4_addrs[k].plen, NULL, false, 0,
>> -                          &peer->nbrp->header_, false,
>> -                          ROUTE_PRIO_OFFSET_CONNECTED);
>> +        const struct lr_lb_nat_data_record *lr_lbnat_rec =
>> +            lr_lb_nat_data_table_find_by_index(lr_lbnats,
>> +                                               router_port->od->index);
>> +
>> +        if (router_port->nbrp->ha_chassis_group ||
>> +                router_port->nbrp->n_gateway_chassis) {
>> +            struct ovn_port_routable_addresses ra =
>> +                get_op_routable_addresses(router_port, lr_lbnat_rec);
>> +            for (size_t j = 0; j < ra.n_addrs; j++) {
>> +                struct lport_addresses *laddrs = &ra.laddrs[j];
>> +                for (size_t k = 0; k < laddrs->n_ipv4_addrs; k++) {
>> +                    add_route(lflows, peer->od, peer,
>> +                            peer->lrp_networks.ipv4_addrs[0].addr_s,
>> +                            laddrs->ipv4_addrs[k].network_s,
>> +                            laddrs->ipv4_addrs[k].plen, NULL, false, 0,
>> +                            &peer->nbrp->header_, false,
>> +                            ROUTE_PRIO_OFFSET_CONNECTED);
>> +                }
>>              }
>> +            destroy_routable_addresses(&ra);
>>          }
>>      }
>> +
>>  }
>>  
>>  static void
>> @@ -13656,33 +13392,36 @@ build_arp_resolve_flows_for_lrouter(
>>  
>>  static void
>>  routable_addresses_to_lflows(struct hmap *lflows, struct ovn_port *router_port,
>> -                             struct ovn_port *peer, struct ds *match,
>> -                             struct ds *actions)
>> +                             struct ovn_port *peer,
>> +                             const struct lr_lb_nat_data_record *lr_lbnat_rec,
>> +                             struct ds *match, struct ds *actions)
>>  {
>> -    struct ovn_port_routable_addresses *ra = &router_port->routables;
>> -    if (!ra->n_addrs) {
>> +    struct ovn_port_routable_addresses ra =
>> +        get_op_routable_addresses(router_port, lr_lbnat_rec);
>> +    if (!ra.n_addrs) {
>>          return;
>>      }
>>  
>> -    for (size_t i = 0; i < ra->n_addrs; i++) {
>> +    for (size_t i = 0; i < ra.n_addrs; i++) {
>>          ds_clear(match);
>>          ds_put_format(match, "outport == %s && "REG_NEXT_HOP_IPV4" == {",
>>                        peer->json_key);
>>          bool first = true;
>> -        for (size_t j = 0; j < ra->laddrs[i].n_ipv4_addrs; j++) {
>> +        for (size_t j = 0; j < ra.laddrs[i].n_ipv4_addrs; j++) {
>>              if (!first) {
>>                  ds_put_cstr(match, ", ");
>>              }
>> -            ds_put_cstr(match, ra->laddrs[i].ipv4_addrs[j].addr_s);
>> +            ds_put_cstr(match, ra.laddrs[i].ipv4_addrs[j].addr_s);
>>              first = false;
>>          }
>>          ds_put_cstr(match, "}");
>>  
>>          ds_clear(actions);
>> -        ds_put_format(actions, "eth.dst = %s; next;", ra->laddrs[i].ea_s);
>> +        ds_put_format(actions, "eth.dst = %s; next;", ra.laddrs[i].ea_s);
>>          ovn_lflow_add(lflows, peer->od, S_ROUTER_IN_ARP_RESOLVE, 100,
>>                        ds_cstr(match), ds_cstr(actions));
>>      }
>> +    destroy_routable_addresses(&ra);
>>  }
>>  
>>  /* Local router ingress table ARP_RESOLVE: ARP Resolution.
>> @@ -13699,6 +13438,7 @@ routable_addresses_to_lflows(struct hmap *lflows, struct ovn_port *router_port,
>>  static void
>>  build_arp_resolve_flows_for_lrp(
>>          struct ovn_port *op, const struct lr_nat_record *lrnat_rec,
>> +        const struct lr_lb_nat_data_record *lr_lbnat_rec,
>>          struct hmap *lflows, struct ds *match, struct ds *actions)
>>  {
>>      ovs_assert(op->nbrp);
>> @@ -13775,8 +13515,8 @@ build_arp_resolve_flows_for_lrp(
>>       *
>>       * Priority 2.
>>       */
>> -    build_lrouter_drop_own_dest(op, lrnat_rec, S_ROUTER_IN_ARP_RESOLVE, 2,
>> -                                true, lflows);
>> +    build_lrouter_drop_own_dest(op, lrnat_rec, lr_lbnat_rec,
>> +                                S_ROUTER_IN_ARP_RESOLVE, 2, true, lflows);
>>  }
>>  
>>  /* This function adds ARP resolve flows related to a LSP. */
>> @@ -13784,6 +13524,7 @@ static void
>>  build_arp_resolve_flows_for_lsp(
>>          struct ovn_port *op, struct hmap *lflows,
>>          const struct hmap *lr_ports,
>> +        const struct lr_lb_nat_data_table *lr_lbnats,
>>          struct ds *match, struct ds *actions)
>>  {
>>      ovs_assert(op->nbsp);
>> @@ -13927,8 +13668,11 @@ build_arp_resolve_flows_for_lsp(
>>  
>>              if (smap_get(&peer->od->nbr->options, "chassis")
>>                  || peer->cr_port) {
>> +                const struct lr_lb_nat_data_record *lr_lbnat_rec;
>> +                lr_lbnat_rec = lr_lb_nat_data_table_find_by_index(lr_lbnats,
>> +                                                    router_port->od->index);
>>                  routable_addresses_to_lflows(lflows, router_port, peer,
>> -                                             match, actions);
>> +                                             lr_lbnat_rec, match, actions);
>>              }
>>          }
>>      }
>> @@ -14648,6 +14392,7 @@ static void
>>  build_lrouter_ipv4_ip_input(struct ovn_port *op,
>>                              struct hmap *lflows,
>>                              const struct lr_nat_record *lrnat_rec,
>> +                            const struct lr_lb_nat_data_record *lr_lbnat_rec,
>>                              struct ds *match, struct ds *actions,
>>                              const struct shash *meter_groups)
>>  {
>> @@ -14772,7 +14517,7 @@ build_lrouter_ipv4_ip_input(struct ovn_port *op,
>>                                 &op->nbrp->header_, lflows);
>>      }
>>  
>> -    if (sset_count(&op->od->lb_ips->ips_v4_reachable)) {
>> +    if (lr_lbnat_rec && sset_count(&lr_lbnat_rec->lb_ips->ips_v4_reachable)) {
>>          ds_clear(match);
>>          if (is_l3dgw_port(op)) {
>>              ds_put_format(match, "is_chassis_resident(%s)",
>> @@ -14788,7 +14533,7 @@ build_lrouter_ipv4_ip_input(struct ovn_port *op,
>>          free(lb_ips_v4_as);
>>      }
>>  
>> -    if (sset_count(&op->od->lb_ips->ips_v6_reachable)) {
>> +    if (lr_lbnat_rec && sset_count(&lr_lbnat_rec->lb_ips->ips_v6_reachable)) {
>>          ds_clear(match);
>>  
>>          if (is_l3dgw_port(op)) {
>> @@ -14890,8 +14635,8 @@ build_lrouter_ipv4_ip_input(struct ovn_port *op,
>>       * Priority 60.
>>       */
>>      if (!lrnat_rec->lb_force_snat_router_ip) {
>> -        build_lrouter_drop_own_dest(op, lrnat_rec, S_ROUTER_IN_IP_INPUT, 60,
>> -                                    false, lflows);
>> +        build_lrouter_drop_own_dest(op, lrnat_rec, lr_lbnat_rec,
>> +                                    S_ROUTER_IN_IP_INPUT, 60, false, lflows);
>>      }
>>      /* ARP / ND handling for external IP addresses.
>>       *
>> @@ -16030,6 +15775,7 @@ struct lswitch_flow_build_info {
>>      const struct hmap *lr_ports;
>>      const struct ls_port_group_table *ls_port_groups;
>>      const struct lr_nat_table *lr_nats;
>> +    const struct lr_lb_nat_data_table *lr_lbnats;
>>      struct hmap *lflows;
>>      struct hmap *igmp_groups;
>>      const struct shash *meter_groups;
>> @@ -16113,14 +15859,15 @@ build_lswitch_and_lrouter_iterate_by_lr(struct ovn_datapath *od,
>>   * switch port.
>>   */
>>  static void
>> -build_lswitch_and_lrouter_iterate_by_lsp(struct ovn_port *op,
>> -                                         const struct hmap *ls_ports,
>> -                                         const struct hmap *lr_ports,
>> -                                         const struct lr_nat_table *lr_nats,
>> -                                         const struct shash *meter_groups,
>> -                                         struct ds *match,
>> -                                         struct ds *actions,
>> -                                         struct hmap *lflows)
>> +build_lswitch_and_lrouter_iterate_by_lsp(
>> +    struct ovn_port *op, const struct hmap *ls_ports,
>> +    const struct hmap *lr_ports,
>> +    const struct lr_nat_table *lr_nats,
>> +    const struct lr_lb_nat_data_table *lr_lbnats,
>> +    const struct shash *meter_groups,
>> +    struct ds *match,
>> +    struct ds *actions,
>> +    struct hmap *lflows)
>>  {
>>      ovs_assert(op->nbsp);
>>      start_collecting_lflows();
>> @@ -16133,11 +15880,14 @@ build_lswitch_and_lrouter_iterate_by_lsp(struct ovn_port *op,
>>                                               meter_groups, actions, match);
>>      build_lswitch_dhcp_options_and_response(op, lflows, meter_groups);
>>      build_lswitch_external_port(op, lflows);
>> -    build_lswitch_ip_unicast_lookup(op, lr_nats, lflows, actions, match);
>> +    build_lswitch_ip_unicast_lookup(op, lr_nats, lr_lbnats, lflows, actions,
>> +                                    match);
>>  
>>      /* Build Logical Router Flows. */
>> -    build_ip_routing_flows_for_router_type_lsp(op, lr_ports, lflows);
>> -    build_arp_resolve_flows_for_lsp(op, lflows, lr_ports, match, actions);
>> +    build_ip_routing_flows_for_router_type_lsp(op, lr_lbnats, lr_ports,
>> +                                               lflows);
>> +    build_arp_resolve_flows_for_lsp(op, lflows, lr_ports, lr_lbnats,
>> +                                    match, actions);
>>  
>>      link_ovn_port_to_lflows(op, &collected_lflows);
>>      end_collecting_lflows();
>> @@ -16156,6 +15906,8 @@ build_lswitch_and_lrouter_iterate_by_lrp(struct ovn_port *op,
>>          lsi->lr_nats, op->od->index);
>>      ovs_assert(lrnet_rec);
>>  
>> +    const struct lr_lb_nat_data_record *lr_lbnat_rec =
>> +        lr_lb_nat_data_table_find_by_index(lsi->lr_lbnats, op->od->index);
>>      build_adm_ctrl_flows_for_lrouter_port(op, lsi->lflows, &lsi->match,
>>                                            &lsi->actions);
>>      build_neigh_learning_flows_for_lrouter_port(op, lsi->lflows, &lsi->match,
>> @@ -16163,15 +15915,15 @@ build_lswitch_and_lrouter_iterate_by_lrp(struct ovn_port *op,
>>      build_ip_routing_flows_for_lrp(op, lsi->lflows);
>>      build_ND_RA_flows_for_lrouter_port(op, lsi->lflows, &lsi->match,
>>                                         &lsi->actions, lsi->meter_groups);
>> -    build_arp_resolve_flows_for_lrp(op, lrnet_rec, lsi->lflows, &lsi->match,
>> -                                    &lsi->actions);
>> +    build_arp_resolve_flows_for_lrp(op, lrnet_rec, lr_lbnat_rec, lsi->lflows,
>> +                                    &lsi->match, &lsi->actions);
>>      build_egress_delivery_flows_for_lrouter_port(op, lsi->lflows, &lsi->match,
>>                                                   &lsi->actions);
>>      build_dhcpv6_reply_flows_for_lrouter_port(op, lsi->lflows, &lsi->match);
>>      build_ipv6_input_flows_for_lrouter_port(op, lsi->lflows,
>>                                              &lsi->match, &lsi->actions,
>>                                              lsi->meter_groups);
>> -    build_lrouter_ipv4_ip_input(op, lsi->lflows, lrnet_rec,
>> +    build_lrouter_ipv4_ip_input(op, lsi->lflows, lrnet_rec, lr_lbnat_rec,
>>                                  &lsi->match, &lsi->actions, lsi->meter_groups);
>>      build_lrouter_force_snat_flows_op(op, lrnet_rec, lsi->lflows, &lsi->match,
>>                                        &lsi->actions);
>> @@ -16234,6 +15986,7 @@ build_lflows_thread(void *arg)
>>                      build_lswitch_and_lrouter_iterate_by_lsp(op, lsi->ls_ports,
>>                                                               lsi->lr_ports,
>>                                                               lsi->lr_nats,
>> +                                                             lsi->lr_lbnats,
>>                                                               lsi->meter_groups,
>>                                                               &lsi->match,
>>                                                               &lsi->actions,
>> @@ -16344,6 +16097,7 @@ build_lswitch_and_lrouter_flows(const struct ovn_datapaths *ls_datapaths,
>>                                  const struct hmap *lr_ports,
>>                                  const struct ls_port_group_table *ls_pgs,
>>                                  const struct lr_nat_table *lr_nats,
>> +                                const struct lr_lb_nat_data_table *lr_lbnats,
>>                                  struct hmap *lflows,
>>                                  struct hmap *igmp_groups,
>>                                  const struct shash *meter_groups,
>> @@ -16374,6 +16128,7 @@ build_lswitch_and_lrouter_flows(const struct ovn_datapaths *ls_datapaths,
>>              lsiv[index].lr_ports = lr_ports;
>>              lsiv[index].ls_port_groups = ls_pgs;
>>              lsiv[index].lr_nats = lr_nats;
>> +            lsiv[index].lr_lbnats = lr_lbnats;
>>              lsiv[index].igmp_groups = igmp_groups;
>>              lsiv[index].meter_groups = meter_groups;
>>              lsiv[index].lb_dps_map = lb_dps_map;
>> @@ -16409,6 +16164,7 @@ build_lswitch_and_lrouter_flows(const struct ovn_datapaths *ls_datapaths,
>>              .lr_ports = lr_ports,
>>              .ls_port_groups = ls_pgs,
>>              .lr_nats = lr_nats,
>> +            .lr_lbnats = lr_lbnats,
>>              .lflows = lflows,
>>              .igmp_groups = igmp_groups,
>>              .meter_groups = meter_groups,
>> @@ -16437,6 +16193,7 @@ build_lswitch_and_lrouter_flows(const struct ovn_datapaths *ls_datapaths,
>>              build_lswitch_and_lrouter_iterate_by_lsp(op, lsi.ls_ports,
>>                                                       lsi.lr_ports,
>>                                                       lsi.lr_nats,
>> +                                                     lsi.lr_lbnats,
>>                                                       lsi.meter_groups,
>>                                                       &lsi.match, &lsi.actions,
>>                                                       lsi.lflows);
>> @@ -16558,6 +16315,7 @@ void build_lflows(struct ovsdb_idl_txn *ovnsb_txn,
>>                                      input_data->lr_ports,
>>                                      input_data->ls_port_groups,
>>                                      input_data->lr_nats,
>> +                                    input_data->lr_lbnats,
>>                                      lflows,
>>                                      &igmp_groups,
>>                                      input_data->meter_groups,
>> @@ -17038,6 +16796,7 @@ lflow_handle_northd_port_changes(struct ovsdb_idl_txn *ovnsb_txn,
>>          build_lswitch_and_lrouter_iterate_by_lsp(op, lflow_input->ls_ports,
>>                                                   lflow_input->lr_ports,
>>                                                   lflow_input->lr_nats,
>> +                                                 lflow_input->lr_lbnats,
>>                                                   lflow_input->meter_groups,
>>                                                   &match, &actions,
>>                                                   lflows);
>> @@ -17076,6 +16835,7 @@ lflow_handle_northd_port_changes(struct ovsdb_idl_txn *ovnsb_txn,
>>          build_lswitch_and_lrouter_iterate_by_lsp(op, lflow_input->ls_ports,
>>                                                      lflow_input->lr_ports,
>>                                                      lflow_input->lr_nats,
>> +                                                    lflow_input->lr_lbnats,
>>                                                      lflow_input->meter_groups,
>>                                                      &match, &actions,
>>                                                      lflows);
>> diff --git a/northd/northd.h b/northd/northd.h
>> index 564729ebcc..7c446f5758 100644
>> --- a/northd/northd.h
>> +++ b/northd/northd.h
>> @@ -179,6 +179,7 @@ struct lflow_input {
>>      const struct hmap *lr_ports;
>>      const struct ls_port_group_table *ls_port_groups;
>>      const struct lr_nat_table *lr_nats;
>> +    const struct lr_lb_nat_data_table *lr_lbnats;
>>      const struct shash *meter_groups;
>>      const struct hmap *lb_datapaths_map;
>>      const struct hmap *bfd_connections;
>> @@ -318,9 +319,6 @@ struct ovn_datapath {
>>      /* router datapath has a logical port with redirect-type set to bridged. */
>>      bool redirect_bridged;
>>  
>> -    /* Load Balancer vIPs relevant for this datapath. */
>> -    struct ovn_lb_ip_set *lb_ips;
>> -
>>      struct ovn_port **localnet_ports;
>>      size_t n_localnet_ports;
>>  
>> @@ -337,6 +335,119 @@ struct ovn_datapath {
>>  const struct ovn_datapath *ovn_datapath_find(const struct hmap *datapaths,
>>                                               const struct uuid *uuid);
>>  
>> +/* A logical switch port or logical router port.
>> + *
>> + * In steady state, an ovn_port points to a northbound Logical_Switch_Port
>> + * record (via 'nbsp') *or* a Logical_Router_Port record (via 'nbrp'), and to a
>> + * southbound Port_Binding record (via 'sb').  As the state of the system
>> + * changes, join_logical_ports() may determine that there is a new LSP or LRP
>> + * that has no corresponding Port_Binding record (in which case build_ports())
>> + * will create the missing Port_Binding) or that a Port_Binding record exists
>> + * that has no coresponding LSP (in which case build_ports() will delete the
>> + * spurious Port_Binding).  Thus, after build_ports() runs, any given ovn_port
>> + * will have 'sb' nonnull, and 'nbsp' xor 'nbrp' nonnull.
>> + *
>> + * Ordinarily there is only one ovn_port that points to a given LSP or LRP (but
>> + * distributed gateway ports point a "derived" ovn_port to a duplicate LRP).
>> + */
>> +struct ovn_port {
>> +    /* Port name aka key.
>> +     *
>> +     * This is ordinarily the same as nbsp->name or nbrp->name and
>> +     * sb->logical_port.  (A distributed gateway port creates a "derived"
>> +     * ovn_port with key "cr-%s" % nbrp->name.) */
>> +    struct hmap_node key_node;  /* Index on 'key'. */
>> +    char *key;                  /* nbsp->name, nbrp->name, sb->logical_port. */
>> +    char *json_key;             /* 'key', quoted for use in JSON. */
>> +
>> +    const struct sbrec_port_binding *sb;         /* May be NULL. */
>> +
>> +    uint32_t tunnel_key;
>> +
>> +    /* Logical switch port data. */
>> +    const struct nbrec_logical_switch_port *nbsp; /* May be NULL. */
>> +
>> +    struct lport_addresses *lsp_addrs;  /* Logical switch port addresses. */
>> +    unsigned int n_lsp_addrs;  /* Total length of lsp_addrs. */
>> +    unsigned int n_lsp_non_router_addrs; /* Number of elements from the
>> +                                          * beginning of 'lsp_addrs' extracted
>> +                                          * directly from LSP 'addresses'. */
>> +
>> +    struct lport_addresses *ps_addrs;   /* Port security addresses. */
>> +    unsigned int n_ps_addrs;
>> +
>> +    bool lsp_can_be_inc_processed; /* If it can be incrementally processed when
>> +                                      the port changes. */
>> +
>> +    /* Logical router port data. */
>> +    const struct nbrec_logical_router_port *nbrp; /* May be NULL. */
>> +
>> +    struct lport_addresses lrp_networks;
>> +
>> +    /* Logical port multicast data. */
>> +    struct mcast_port_info mcast_info;
>> +
>> +    /* At most one of l3dgw_port and cr_port can be not NULL. */
>> +
>> +    /* This is set to a distributed gateway port if and only if this ovn_port
>> +     * is "derived" from it. Otherwise this is set to NULL. The derived
>> +     * ovn_port represents the instance of distributed gateway port on the
>> +     * gateway chassis.*/
>> +    struct ovn_port *l3dgw_port;
>> +
>> +    /* This is set to the "derived" chassis-redirect port of this port if and
>> +     * only if this port is a distributed gateway port. Otherwise this is set
>> +     * to NULL. */
>> +    struct ovn_port *cr_port;
>> +
>> +    bool has_unknown; /* If the addresses have 'unknown' defined. */
>> +
>> +    bool has_bfd;
>> +
>> +    /* The port's peer:
>> +     *
>> +     *     - A switch port S of type "router" has a router port R as a peer,
>> +     *       and R in turn has S has its peer.
>> +     *
>> +     *     - Two connected logical router ports have each other as peer.
>> +     *
>> +     *     - Other kinds of ports have no peer. */
>> +    struct ovn_port *peer;
>> +
>> +    struct ovn_datapath *od;
>> +
>> +    struct ovs_list list;       /* In list of similar records. */
>> +
>> +    struct hmap_node dp_node;   /* Node in od->ports. */
>> +
>> +    struct lport_addresses proxy_arp_addrs;
>> +
>> +    /* Temporarily used for traversing a list (or hmap) of ports. */
>> +    bool visited;
>> +
>> +    /* List of struct lflow_ref_node that points to the lflows generated by
>> +     * this ovn_port.
>> +     *
>> +     * This data is initialized and destroyed by the en_northd node, but
>> +     * populated and used only by the en_lflow node. Ideally this data should
>> +     * be maintained as part of en_lflow's data (struct lflow_data): a hash
>> +     * index from ovn_port key to lflows.  However, it would be less efficient
>> +     * and more complex:
>> +     *
>> +     * 1. It would require an extra search (using the index) to find the
>> +     * lflows.
>> +     *
>> +     * 2. Building the index needs to be thread-safe, using either a global
>> +     * lock which is obviously less efficient, or hash-based lock array which
>> +     * is more complex.
>> +     *
>> +     * Adding the list here is more straightforward. The drawback is that we
>> +     * need to keep in mind that this data belongs to en_lflow node, so never
>> +     * access it from any other nodes.
>> +     */
>> +    struct ovs_list lflows;
>> +};
>> +
>>  void ovnnb_db_run(struct northd_input *input_data,
>>                    struct northd_data *data,
>>                    struct ovsdb_idl_txn *ovnnb_txn,
>> @@ -396,13 +507,27 @@ void sync_lbs(struct ovsdb_idl_txn *, const struct sbrec_load_balancer_table *,
>>                struct chassis_features *chassis_features);
>>  bool check_sb_lb_duplicates(const struct sbrec_load_balancer_table *);
>>  
>> +struct lr_lb_nat_data_table;
>>  void sync_pbs(struct ovsdb_idl_txn *, struct hmap *ls_ports,
>> -              struct hmap *lr_ports, const struct lr_nat_table *);
>> -bool sync_pbs_for_northd_changed_ovn_ports(struct tracked_ovn_ports *,
>> -                                           const struct lr_nat_table *);
>> +              struct hmap *lr_ports,
>> +              const struct lr_lb_nat_data_table *);
>> +bool sync_pbs_for_northd_changed_ovn_ports(
>> +    struct tracked_ovn_ports *,
>> +    const struct lr_lb_nat_data_table *);
>>  
>>  bool northd_has_tracked_data(struct northd_tracked_data *);
>>  bool northd_has_only_ports_in_tracked_data(struct northd_tracked_data *);
>>  bool northd_has_lbs_in_tracked_data(struct northd_tracked_data *);
>>  
>> +/* Returns 'true' if the IPv4 'addr' is on the same subnet with one of the
>> + * IPs configured on the router port.
>> + */
>> +bool lrouter_port_ipv4_reachable(const struct ovn_port *, ovs_be32 addr);
>> +
>> +/* Returns 'true' if the IPv6 'addr' is on the same subnet with one of the
>> + * IPs configured on the router port.
>> + */
>> +bool lrouter_port_ipv6_reachable(const struct ovn_port *,
>> +                                 const struct in6_addr *);
>> +
>>  #endif /* NORTHD_H */
>> diff --git a/tests/ovn-northd.at b/tests/ovn-northd.at
>> index b7f9cb5689..8fc5cd1d60 100644
>> --- a/tests/ovn-northd.at
>> +++ b/tests/ovn-northd.at
>> @@ -10416,18 +10416,21 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb set load_balancer . ip_port_mappings:10.0.0.3=sw0-p1:10.0.0.2
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute nocompute
>>  
>>  check ovn-nbctl --wait=sb set load_balancer . options:foo=bar
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute nocompute
>>  
>>  check ovn-nbctl --wait=sb -- lb-add lb2 20.0.0.10:80 20.0.0.20:80 -- lb-add lb3 30.0.0.10:80 30.0.0.20:80
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute nocompute
>>  
>> @@ -10437,6 +10440,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb -- lb-del lb2 -- lb-del lb3
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute nocompute
>>  
>> @@ -10450,6 +10454,7 @@ AT_CHECK([ovn-nbctl --wait=sb \
>>  ])
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd recompute nocompute
>> +check_engine_stats lr_lb_nat_data recompute nocompute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute nocompute
>>  
>> @@ -10467,6 +10472,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb clear Load_Balancer . health_check
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd recompute nocompute
>> +check_engine_stats lr_lb_nat_data recompute nocompute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute nocompute
>>  
>> @@ -10481,6 +10487,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  ovn-nbctl --wait=sb lsp-set-options sw0-lr0 router-port=lr0-sw0
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd recompute nocompute
>> +check_engine_stats lr_lb_nat_data recompute nocompute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute nocompute
>>  
>> @@ -10489,6 +10496,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb ls-lb-add sw0 lb1
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  # A LB applied to a switch/router triggers:
>>  # - a recompute in the first iteration (handling northd change)
>> @@ -10501,6 +10509,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb set load_balancer lb1 vips:'"10.0.0.10:80"'='"10.0.0.100:80"'
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10510,6 +10519,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb clear load_Balancer lb1 vips
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10519,6 +10529,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb lb-add lb1 10.0.0.10:80 10.0.0.3:80
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10528,6 +10539,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb lb-add lb1 10.0.0.20:80 10.0.0.30:8080
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10537,6 +10549,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb ls-lb-del sw0 lb1
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd recompute nocompute
>> +check_engine_stats lr_lb_nat_data recompute nocompute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10547,6 +10560,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb ls-lb-add sw0 lb1 -- lsp-add sw0 sw0p1
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  
>> @@ -10567,6 +10581,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb lr-lb-add lr0 lb1
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10576,6 +10591,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb set load_balancer lb1 vips:'"10.0.0.10:80"'='"10.0.0.100:80"'
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10585,6 +10601,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb clear load_Balancer lb1 vips
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10594,6 +10611,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb lb-add lb1 10.0.0.10:80 10.0.0.3:80
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10603,6 +10621,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb lb-add lb1 10.0.0.20:80 10.0.0.30:8080
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10632,6 +10651,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb add load_balancer_group . load_Balancer $lb1_uuid
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute nocompute
>>  
>> @@ -10639,6 +10659,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb clear load_balancer_group . load_Balancer
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd recompute nocompute
>> +check_engine_stats lr_lb_nat_data recompute nocompute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute nocompute
>>  
>> @@ -10655,6 +10676,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb add logical_switch sw0 load_balancer_group $lbg1_uuid
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  
>> @@ -10671,6 +10693,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb set load_balancer lb1 vips:'"10.0.0.10:80"'='"10.0.0.100:80"'
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10680,6 +10703,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb clear load_Balancer lb1 vips
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10689,6 +10713,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb lb-add lb1 10.0.0.10:80 10.0.0.3:80
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10698,6 +10723,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb lb-add lb1 10.0.0.20:80 10.0.0.30:8080
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10713,6 +10739,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl add logical_router lr0 load_balancer_group $lbg1_uuid
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10722,6 +10749,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb set load_balancer lb1 vips:'"10.0.0.10:80"'='"10.0.0.100:80"'
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10731,6 +10759,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb clear load_Balancer lb1 vips
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10740,6 +10769,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb lb-add lb1 10.0.0.10:80 10.0.0.3:80
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10749,6 +10779,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb lb-add lb1 10.0.0.20:80 10.0.0.30:8080
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10757,6 +10788,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb clear logical_router lr0 load_balancer_group
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd recompute nocompute
>> +check_engine_stats lr_lb_nat_data recompute nocompute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  
>> @@ -10765,6 +10797,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb add logical_switch sw0 load_balancer_group $lbg1_uuid
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  
>> @@ -10773,6 +10806,7 @@ check ovn-nbctl --wait=sb clear logical_switch sw0 load_balancer_group -- \
>>      destroy load_balancer_group $lbg1_uuid
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd recompute nocompute
>> +check_engine_stats lr_lb_nat_data recompute nocompute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb compute compute
>>  
>> @@ -10796,6 +10830,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  lbg1_uuid=$(ovn-nbctl --wait=sb create load_balancer_group name=lbg1)
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow norecompute nocompute
>>  check_engine_stats sync_to_sb_lb norecompute nocompute
>>  
>> @@ -10803,6 +10838,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb set load_balancer_group . load_balancer="$lb2_uuid,$lb3_uuid,$lb4_uuid"
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute nocompute
>>  
>> @@ -10810,6 +10846,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb set logical_switch sw0 load_balancer_group=$lbg1_uuid
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10818,6 +10855,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb set logical_router lr1 load_balancer_group=$lbg1_uuid
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10826,6 +10864,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb ls-lb-add sw0 lb2
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute nocompute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10834,6 +10873,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb ls-lb-add sw0 lb3
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute nocompute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10843,6 +10883,7 @@ check ovn-nbctl --wait=sb lr-lb-add lr1 lb1
>>  check ovn-nbctl --wait=sb lr-lb-add lr1 lb2
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10851,6 +10892,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb ls-lb-del sw0 lb2
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd recompute nocompute
>> +check_engine_stats lr_lb_nat_data recompute nocompute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute nocompute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10859,6 +10901,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb lr-lb-del lr1 lb2
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd recompute nocompute
>> +check_engine_stats lr_lb_nat_data recompute nocompute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute nocompute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10869,6 +10912,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb lb-del lb4
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10879,6 +10923,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb lb-del lb2
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -10887,6 +10932,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb remove load_balancer_group . load_balancer $lb3_uuid
>>  check_engine_stats lb_data norecompute compute
>>  check_engine_stats northd recompute nocompute
>> +check_engine_stats lr_lb_nat_data recompute nocompute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_lb recompute compute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -11019,6 +11065,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb lr-add lr0
>>  check_engine_stats northd recompute nocompute
>>  check_engine_stats lr_nat recompute nocompute
>> +check_engine_stats lr_lb_nat_data recompute nocompute
>>  check_engine_stats sync_to_sb_pb recompute nocompute
>>  check_engine_stats lflow recompute nocompute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -11031,6 +11078,7 @@ check ovn-nbctl lrp-add lr0 lr0-sw0 00:00:00:00:ff:01 10.0.0.1/24
>>  # for the SB port binding change.
>>  check_engine_stats northd recompute compute
>>  check_engine_stats lr_nat recompute nocompute
>> +check_engine_stats lr_lb_nat_data recompute nocompute
>>  check_engine_stats sync_to_sb_pb recompute nocompute
>>  check_engine_stats lflow recompute nocompute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -11042,6 +11090,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb lsp-set-options sw0-lr0 router-port=lr0-sw0
>>  check_engine_stats northd recompute nocompute
>>  check_engine_stats lr_nat recompute nocompute
>> +check_engine_stats lr_lb_nat_data recompute nocompute
>>  check_engine_stats sync_to_sb_pb recompute nocompute
>>  check_engine_stats lflow recompute nocompute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -11067,6 +11116,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl set logical_router_port lr0-sw0 options:foo=bar
>>  check_engine_stats northd recompute nocompute
>>  check_engine_stats lr_nat recompute nocompute
>> +check_engine_stats lr_lb_nat_data recompute nocompute
>>  check_engine_stats sync_to_sb_pb recompute nocompute
>>  check_engine_stats lflow recompute nocompute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -11076,8 +11126,8 @@ CHECK_NO_CHANGE_AFTER_RECOMPUTE
>>  # engine nodes.
>>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb lr-nat-add lr0 dnat_and_snat  172.168.0.110 10.0.0.4
>> -check_engine_stats northd recompute nocompute
>> -check_engine_stats lr_nat recompute nocompute
>> +check_engine_stats northd norecompute compute
>> +check_engine_stats lr_nat norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_pb recompute nocompute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -11085,8 +11135,8 @@ CHECK_NO_CHANGE_AFTER_RECOMPUTE
>>  # Update the NAT options column
>>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb set NAT . options:foo=bar
>> -check_engine_stats northd recompute nocompute
>> -check_engine_stats lr_nat recompute nocompute
>> +check_engine_stats northd norecompute compute
>> +check_engine_stats lr_nat norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_pb recompute nocompute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -11094,8 +11144,9 @@ CHECK_NO_CHANGE_AFTER_RECOMPUTE
>>  # Update the NAT external_ip column
>>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb set NAT . external_ip=172.168.0.120
>> -check_engine_stats northd recompute nocompute
>> -check_engine_stats lr_nat recompute nocompute
>> +check_engine_stats northd norecompute compute
>> +check_engine_stats lr_nat norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_pb recompute nocompute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -11103,8 +11154,9 @@ CHECK_NO_CHANGE_AFTER_RECOMPUTE
>>  # Update the NAT logical_ip column
>>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb set NAT . logical_ip=10.0.0.10
>> -check_engine_stats northd recompute nocompute
>> -check_engine_stats lr_nat recompute nocompute
>> +check_engine_stats northd norecompute compute
>> +check_engine_stats lr_nat norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_pb recompute nocompute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -11112,8 +11164,9 @@ CHECK_NO_CHANGE_AFTER_RECOMPUTE
>>  # Update the NAT type
>>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb set NAT . type=snat
>> -check_engine_stats northd recompute nocompute
>> -check_engine_stats lr_nat recompute nocompute
>> +check_engine_stats northd norecompute compute
>> +check_engine_stats lr_nat norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_pb recompute nocompute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -11121,8 +11174,9 @@ CHECK_NO_CHANGE_AFTER_RECOMPUTE
>>  # Create a dnat_and_snat NAT with external_mac and logical_port
>>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb lr-nat-add lr0 dnat_and_snat 172.168.0.110 10.0.0.4 sw0p1 30:54:00:00:00:03
>> -check_engine_stats northd recompute compute
>> -check_engine_stats lr_nat recompute nocompute
>> +check_engine_stats northd norecompute compute
>> +check_engine_stats lr_nat norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_pb recompute nocompute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -11131,8 +11185,9 @@ nat2_uuid=$(ovn-nbctl --bare --columns _uuid find nat logical_ip=10.0.0.4)
>>  
>>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb set NAT $nat2_uuid external_mac='"30:54:00:00:00:04"'
>> -check_engine_stats northd recompute nocompute
>> -check_engine_stats lr_nat recompute nocompute
>> +check_engine_stats northd norecompute compute
>> +check_engine_stats lr_nat norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_pb recompute nocompute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -11147,32 +11202,36 @@ check ovn-nbctl lr-lb-add lr0 lb2
>>  # is a lb vip.
>>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb lr-nat-add lr0 dnat_and_snat 172.168.0.140 10.0.0.20
>> -check_engine_stats northd recompute nocompute
>> -check_engine_stats lr_nat recompute nocompute
>> +check_engine_stats northd norecompute compute
>> +check_engine_stats lr_nat norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats sync_to_sb_pb recompute nocompute
>>  check_engine_stats lflow recompute nocompute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>>  
>>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb lr-nat-add lr0 dnat_and_snat 172.168.0.150 10.0.0.41
>> -check_engine_stats northd recompute nocompute
>> -check_engine_stats lr_nat recompute nocompute
>> +check_engine_stats northd norecompute compute
>> +check_engine_stats lr_nat norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats sync_to_sb_pb recompute nocompute
>>  check_engine_stats lflow recompute nocompute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>>  
>>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb lr-nat-del lr0 dnat_and_snat 172.168.0.150
>> -check_engine_stats northd recompute nocompute
>> -check_engine_stats lr_nat recompute nocompute
>> +check_engine_stats northd norecompute compute
>> +check_engine_stats lr_nat norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats sync_to_sb_pb recompute nocompute
>>  check_engine_stats lflow recompute nocompute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>>  
>>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb lr-nat-del lr0 dnat_and_snat 172.168.0.140
>> -check_engine_stats northd recompute nocompute
>> -check_engine_stats lr_nat recompute nocompute
>> +check_engine_stats northd norecompute compute
>> +check_engine_stats lr_nat norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats sync_to_sb_pb recompute nocompute
>>  check_engine_stats lflow recompute nocompute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -11180,8 +11239,9 @@ CHECK_NO_CHANGE_AFTER_RECOMPUTE
>>  # Delete the NAT
>>  check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb clear logical_router lr0 nat
>> -check_engine_stats northd recompute compute
>> -check_engine_stats lr_nat recompute nocompute
>> +check_engine_stats northd norecompute compute
>> +check_engine_stats lr_nat norecompute compute
>> +check_engine_stats lr_lb_nat_data norecompute compute
>>  check_engine_stats lflow recompute nocompute
>>  check_engine_stats sync_to_sb_pb recompute nocompute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -11191,6 +11251,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb lr-policy-add lr0  10 "ip4.src == 10.0.0.3" reroute 172.168.0.101,172.168.0.102
>>  check_engine_stats northd recompute nocompute
>>  check_engine_stats lr_nat recompute nocompute
>> +check_engine_stats lr_lb_nat_data recompute nocompute
>>  check_engine_stats sync_to_sb_pb recompute nocompute
>>  check_engine_stats lflow recompute nocompute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE
>> @@ -11199,6 +11260,7 @@ check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
>>  check ovn-nbctl --wait=sb lr-policy-del lr0  10 "ip4.src == 10.0.0.3"
>>  check_engine_stats northd recompute nocompute
>>  check_engine_stats lr_nat recompute nocompute
>> +check_engine_stats lr_lb_nat_data recompute nocompute
>>  check_engine_stats sync_to_sb_pb recompute nocompute
>>  check_engine_stats lflow recompute nocompute
>>  CHECK_NO_CHANGE_AFTER_RECOMPUTE