diff --git a/northd/en-lflow.c b/northd/en-lflow.c
index 56fe564c82..ad5ebc53fc 100644
--- a/northd/en-lflow.c
+++ b/northd/en-lflow.c
@@ -105,6 +105,10 @@ lflow_northd_handler(struct engine_node *node,
         return false;
     }
 
+    if (northd_data->trk_northd_changes.lb_nats_changed) {
+        return false;
+    }
+
     const struct engine_context *eng_ctx = engine_get_context();
     struct lflow_data *lflow_data = data;
 
@@ -123,6 +127,12 @@ lflow_northd_handler(struct engine_node *node,
         return false;
     }
 
+    if (!lflow_handle_northd_od_changes(eng_ctx->ovnsb_idl_txn,
+                                &northd_data->trk_northd_changes.trk_datapaths,
+                                &lflow_input, lflow_data)) {
+        return false;
+    }
+
     engine_set_node_state(node, EN_UPDATED);
 
     return true;
diff --git a/northd/en-northd.c b/northd/en-northd.c
index b3e84a6af6..5fa9ecbbc1 100644
--- a/northd/en-northd.c
+++ b/northd/en-northd.c
@@ -207,19 +207,41 @@ northd_sb_port_binding_handler(struct engine_node *node,
 }
 
 bool
-northd_nb_logical_router_handler(struct engine_node *node,
-                                 void *data)
+northd_nb_logical_router_handler_pre_lb(struct engine_node *node,
+                                        void *data)
 {
     struct northd_data *nd = data;
     struct northd_input input_data;
 
     northd_get_input_data(node, &input_data);
 
-    if (!northd_handle_lr_changes(&input_data, nd)) {
+    if (!northd_handle_lr_changes_pre_lb(&input_data, nd)) {
         return false;
     }
 
-    if (nd->change_tracked) {
+    if (northd_has_tracked_data(&nd->trk_northd_changes)) {
+        nd->change_tracked = true;
+        engine_set_node_state(node, EN_UPDATED);
+    }
+
+    return true;
+}
+
+bool
+northd_nb_logical_router_handler_post_lb(struct engine_node *node,
+                                        void *data)
+{
+    struct northd_data *nd = data;
+    struct northd_input input_data;
+
+    northd_get_input_data(node, &input_data);
+
+    if (!northd_handle_lr_changes_post_lb(&input_data, nd)) {
+        return false;
+    }
+
+    if (northd_has_tracked_data(&nd->trk_northd_changes)) {
+        nd->change_tracked = true;
         engine_set_node_state(node, EN_UPDATED);
     }
 
diff --git a/northd/en-northd.h b/northd/en-northd.h
index 84d8673e1b..02af2a758c 100644
--- a/northd/en-northd.h
+++ b/northd/en-northd.h
@@ -16,7 +16,9 @@ void en_northd_cleanup(void *data);
 void en_northd_clear_tracked_data(void *data);
 bool northd_nb_nb_global_handler(struct engine_node *, void *data OVS_UNUSED);
 bool northd_nb_logical_switch_handler(struct engine_node *, void *data);
-bool northd_nb_logical_router_handler(struct engine_node *, void *data);
+bool northd_nb_logical_router_handler_pre_lb(struct engine_node *, void *data);
+bool northd_nb_logical_router_handler_post_lb(struct engine_node *,
+                                              void *data);
 bool northd_sb_port_binding_handler(struct engine_node *, void *data);
 bool northd_lb_data_handler_pre_od(struct engine_node *, void *data);
 bool northd_lb_data_handler_post_od(struct engine_node *, void *data);
diff --git a/northd/inc-proc-northd.c b/northd/inc-proc-northd.c
index e3bc2bda7b..12a5990521 100644
--- a/northd/inc-proc-northd.c
+++ b/northd/inc-proc-northd.c
@@ -189,8 +189,10 @@ void inc_proc_northd_init(struct ovsdb_idl_loop *nb,
     engine_add_input(&en_northd, &en_nb_logical_switch,
                      northd_nb_logical_switch_handler);
     engine_add_input(&en_northd, &en_nb_logical_router,
-                     northd_nb_logical_router_handler);
+                     northd_nb_logical_router_handler_pre_lb);
     engine_add_input(&en_northd, &en_lb_data, northd_lb_data_handler_post_od);
+    engine_add_input(&en_northd, &en_nb_logical_router,
+                     northd_nb_logical_router_handler_post_lb);
 
     engine_add_input(&en_mac_binding_aging, &en_nb_nb_global, NULL);
     engine_add_input(&en_mac_binding_aging, &en_sb_mac_binding, NULL);
diff --git a/northd/northd.c b/northd/northd.c
index 2ae41b5d8a..28e1f43a38 100644
--- a/northd/northd.c
+++ b/northd/northd.c
@@ -703,6 +703,18 @@ destroy_nat_entries(struct ovn_datapath *od)
     }
 }
 
+static void
+reinit_nat_entries(struct ovn_datapath *od)
+{
+    ovs_assert(od->nbr);
+    destroy_nat_entries(od);
+    od->n_nat_entries = 0;
+    od->has_distributed_nat = false;
+    free(od->nat_entries);
+    od->nat_entries = NULL;
+    init_nat_entries(od);
+}
+
 static void
 init_router_external_ips(struct ovn_datapath *od)
 {
@@ -724,6 +736,14 @@ destroy_router_external_ips(struct ovn_datapath *od)
     sset_destroy(&od->external_ips);
 }
 
+static void
+reinit_router_external_ips(struct ovn_datapath *od)
+{
+    ovs_assert(od->nbr);
+    destroy_router_external_ips(od);
+    init_router_external_ips(od);
+}
+
 static bool
 lb_has_vip(const struct nbrec_load_balancer *lb)
 {
@@ -792,6 +812,47 @@ destroy_lb_for_datapath(struct ovn_datapath *od)
     od->lb_ips = NULL;
 }
 
+/* Initiailizes the router datapath's lb_nats sset which contains
+ * set of NAT ips which are also in the load balancer vips
+ * associated with the router datapath. */
+static void
+init_router_lb_nats(struct ovn_datapath *od)
+{
+    ovs_assert(od->nbr);
+
+    sset_init(&od->lb_nats);
+    const char *external_ip;
+    SSET_FOR_EACH (external_ip, &od->external_ips) {
+        bool is_vip_nat = false;
+        if (addr_is_ipv6(external_ip)) {
+            is_vip_nat = sset_contains(&od->lb_ips->ips_v6, external_ip);
+        } else {
+            is_vip_nat = sset_contains(&od->lb_ips->ips_v4, external_ip);
+        }
+
+        if (is_vip_nat) {
+            sset_add(&od->lb_nats, external_ip);
+        }
+    }
+}
+
+static void
+destroy_router_lb_nats(struct ovn_datapath *od)
+{
+    if (od->nbr) {
+        sset_destroy(&od->lb_nats);
+    }
+}
+
+static void
+build_router_lb_nats(struct hmap *lr_datapaths)
+{
+    struct ovn_datapath *od;
+    HMAP_FOR_EACH (od, key_node, lr_datapaths) {
+        init_router_lb_nats(od);
+    }
+}
+
 /* A group of logical router datapaths which are connected - either
  * directly or indirectly.
  * Each logical router can belong to only one group. */
@@ -847,6 +908,7 @@ ovn_datapath_destroy(struct hmap *datapaths, struct ovn_datapath *od)
         free(od->ls_peers);
         destroy_nat_entries(od);
         destroy_router_external_ips(od);
+        destroy_router_lb_nats(od);
         destroy_lb_for_datapath(od);
         free(od->nat_entries);
         free(od->localnet_ports);
@@ -1594,6 +1656,8 @@ destroy_routable_addresses(struct ovn_port_routable_addresses *ra)
         destroy_lport_addresses(&ra->laddrs[i]);
     }
     free(ra->laddrs);
+    ra->laddrs = NULL;
+    ra->n_addrs = 0;
 }
 
 static char **get_nat_addresses(const struct ovn_port *op, size_t *n,
@@ -1638,6 +1702,14 @@ ovn_port_set_nb(struct ovn_port *op,
         op->lsp_can_be_inc_processed = lsp_can_be_inc_processed(nbsp);
     }
     op->nbrp = nbrp;
+
+    if (nbrp) {
+        if (is_cr_port(op)) {
+            /* ovn-northd doesn't have to do anything when a chassis-redirect
+             * port gets updated as its an internal port created by northd. */
+            op->lsp_can_be_inc_processed = true;
+        }
+    }
     init_mcast_port_info(&op->mcast_info, op->nbsp, op->nbrp);
 }
 
@@ -5071,12 +5143,20 @@ destroy_tracked_lb_datapaths(struct tracked_lb_datapaths *trk_lbs)
     trk_lbs->n_nb_lr = 0;
 }
 
+static void
+destroy_tracked_datapaths(struct tracked_datapaths *trk_dps)
+{
+    hmapx_clear(&trk_dps->crupdated);
+}
+
 void
 destroy_northd_data_tracked_changes(struct northd_data *nd)
 {
     struct northd_tracked_data *trk_changes = &nd->trk_northd_changes;
     destroy_tracked_ovn_ports(&trk_changes->trk_ovn_ports);
     destroy_tracked_lb_datapaths(&trk_changes->trk_lbs);
+    destroy_tracked_datapaths(&trk_changes->trk_datapaths);
+    trk_changes->lb_nats_changed = false;
     nd->change_tracked = false;
 }
 
@@ -5088,7 +5168,8 @@ bool northd_has_tracked_data(struct northd_tracked_data *trk_nd_changes)
             || !hmap_is_empty(&trk_nd_changes->trk_ovn_ports.updated)
             || !hmap_is_empty(&trk_nd_changes->trk_ovn_ports.deleted)
             || !hmapx_is_empty(&trk_nd_changes->trk_lbs.crupdated)
-            || !hmapx_is_empty(&trk_nd_changes->trk_lbs.deleted));
+            || !hmapx_is_empty(&trk_nd_changes->trk_lbs.deleted)
+            || !hmapx_is_empty(&trk_nd_changes->trk_datapaths.crupdated));
 }
 
 bool northd_has_only_ports_in_tracked_data(
@@ -5098,6 +5179,7 @@ bool northd_has_only_ports_in_tracked_data(
             && !trk_nd_changes->trk_lbs.n_nb_lr
             && hmapx_is_empty(&trk_nd_changes->trk_lbs.crupdated)
             && hmapx_is_empty(&trk_nd_changes->trk_lbs.deleted)
+            && hmapx_is_empty(&trk_nd_changes->trk_datapaths.crupdated)
             && (!hmap_is_empty(&trk_nd_changes->trk_ovn_ports.created)
             || !hmap_is_empty(&trk_nd_changes->trk_ovn_ports.updated)
             || !hmap_is_empty(&trk_nd_changes->trk_ovn_ports.deleted)));
@@ -5646,7 +5728,8 @@ check_unsupported_inc_proc_for_lr_changes(
     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) {
+                col == NBREC_LOGICAL_ROUTER_COL_LOAD_BALANCER_GROUP ||
+                col == NBREC_LOGICAL_ROUTER_COL_NAT) {
                 continue;
             }
             return true;
@@ -5665,12 +5748,6 @@ check_unsupported_inc_proc_for_lr_changes(
                                 OVSDB_IDL_CHANGE_MODIFY) > 0) {
         return true;
     }
-    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 true;
-        }
-    }
     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) {
@@ -5686,6 +5763,93 @@ check_unsupported_inc_proc_for_lr_changes(
     return false;
 }
 
+static bool
+handle_lr_nat_changes(const struct nbrec_logical_router *lr,
+                      struct ovn_datapath *od,
+                      bool *changed)
+{
+    /* If nothing has changed, return */
+    bool nat_changed = false;
+    if (nbrec_logical_router_is_updated(lr, NBREC_LOGICAL_ROUTER_COL_NAT)) {
+        nat_changed = true;
+        for (size_t i = 0; i < lr->n_nat; i++) {
+            if ((nbrec_nat_row_get_seqno(lr->nat[i],
+                                         OVSDB_IDL_CHANGE_INSERT) > 0) ||
+                (nbrec_nat_row_get_seqno(lr->nat[i],
+                                         OVSDB_IDL_CHANGE_DELETE) > 0)) {
+                /* Check if the modified NAT has add_route options set.
+                 * If so, return false. */
+                if (smap_get_bool(&lr->nat[i]->options, "add_route", false)) {
+                    return false;
+                }
+                nat_changed = true;
+                break;
+            }
+        }
+    } else {
+        for (size_t i = 0; i < lr->n_nat; i++) {
+            if (nbrec_nat_row_get_seqno(lr->nat[i],
+                                        OVSDB_IDL_CHANGE_MODIFY) > 0) {
+                /* Check if the modified NAT has add_route options set.
+                 * If so, return false. */
+                if (smap_get_bool(&lr->nat[i]->options, "add_route", false)) {
+                    return false;
+                }
+                nat_changed = true;
+                break;
+            }
+        }
+    }
+
+    if (!nat_changed) {
+        return true;
+    }
+
+    *changed = true;
+    reinit_nat_entries(od);
+    reinit_router_external_ips(od);
+    return true;
+}
+
+static bool
+lr_lb_nats_changed(struct ovn_datapath *od)
+{
+    /* Check if NATs changed. */
+    bool nat_changed =
+        nbrec_logical_router_is_updated(od->nbr, NBREC_LOGICAL_ROUTER_COL_NAT);
+
+    if (!nat_changed) {
+        for (size_t i = 0; i < od->nbr->n_nat; i++) {
+            if (nbrec_nat_row_get_seqno(od->nbr->nat[i],
+                                        OVSDB_IDL_CHANGE_MODIFY) > 0) {
+                nat_changed = true;
+                break;
+            }
+        }
+    }
+
+    if (!nat_changed) {
+        return false;
+    }
+
+    struct sset old_lb_nats = SSET_INITIALIZER(&old_lb_nats);
+    bool lb_nats_changed;
+
+    sset_swap(&od->lb_nats, &old_lb_nats);
+    sset_destroy(&od->lb_nats);
+    init_router_lb_nats(od);
+
+    lb_nats_changed = sset_count(&od->lb_nats) != sset_count(&old_lb_nats);
+
+    if (!lb_nats_changed) {
+        lb_nats_changed = !sset_equals(&od->lb_nats, &old_lb_nats);
+    }
+
+    sset_destroy(&old_lb_nats);
+
+    return lb_nats_changed;
+}
+
 /* Return true if changes are handled incrementally, 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,
@@ -5696,8 +5860,8 @@ check_unsupported_inc_proc_for_lr_changes(
  * northd_handle_lb_data_changes_post_od).
  * */
 bool
-northd_handle_lr_changes(const struct northd_input *ni,
-                         struct northd_data *nd)
+northd_handle_lr_changes_pre_lb(const struct northd_input *ni,
+                                struct northd_data *nd)
 {
     const struct nbrec_logical_router *changed_lr;
 
@@ -5713,6 +5877,43 @@ northd_handle_lr_changes(const struct northd_input *ni,
         if (check_unsupported_inc_proc_for_lr_changes(changed_lr)) {
             goto fail;
         }
+
+        struct ovn_datapath *od = ovn_datapath_find(
+            &nd->lr_datapaths.datapaths, &changed_lr->header_.uuid);
+        if (!od) {
+            static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 1);
+            VLOG_WARN_RL(&rl, "Internal error: a tracked updated LR doesn't "
+                        "exist in lr_datapaths: "UUID_FMT,
+                        UUID_ARGS(&changed_lr->header_.uuid));
+            return false;
+        }
+
+        bool lr_nat_changed = false;
+        if (!handle_lr_nat_changes(changed_lr, od,
+                                  &lr_nat_changed)) {
+            goto fail;
+        }
+
+        if (lr_nat_changed) {
+            nd->change_tracked = true;
+            hmapx_add(&nd->trk_northd_changes.trk_datapaths.crupdated, od);
+
+            /* Also add the peer (logical switch port) of logical router ports
+             * to the northd tracked data. */
+            struct ovn_port *op;
+            uint8_t lport_changes =
+                (EN_TRACKED_OP_LPORT_CHANGED | EN_TRACKED_OP_LB_CHANGED);
+            HMAP_FOR_EACH (op, dp_node, &od->ports) {
+                add_op_to_northd_tracked_ports(
+                    &nd->trk_northd_changes.trk_ovn_ports.updated, op,
+                    lport_changes);
+                if (op->peer) {
+                    add_op_to_northd_tracked_ports(
+                        &nd->trk_northd_changes.trk_ovn_ports.updated,
+                        op->peer, lport_changes);
+                }
+            }
+        }
     }
 
     return true;
@@ -5721,6 +5922,26 @@ fail:
     return false;
 }
 
+bool
+northd_handle_lr_changes_post_lb(const struct northd_input *ni,
+                                 struct northd_data *nd)
+{
+    const struct nbrec_logical_router *changed_lr;
+
+    NBREC_LOGICAL_ROUTER_TABLE_FOR_EACH_TRACKED (changed_lr,
+                                             ni->nbrec_logical_router_table) {
+        struct ovn_datapath *od = ovn_datapath_find(
+            &nd->lr_datapaths.datapaths, &changed_lr->header_.uuid);
+        ovs_assert(od);
+
+        if (lr_lb_nats_changed(od)) {
+            nd->trk_northd_changes.lb_nats_changed = true;
+        }
+    }
+
+    return true;
+}
+
 bool
 northd_handle_sb_port_binding_changes(
     const struct sbrec_port_binding_table *sbrec_port_binding_table,
@@ -17118,38 +17339,42 @@ build_lswitch_and_lrouter_iterate_by_ls(struct ovn_datapath *od,
  */
 static void
 build_lswitch_and_lrouter_iterate_by_lr(struct ovn_datapath *od,
-                                        struct lswitch_flow_build_info *lsi)
+                                    const struct shash *meter_groups,
+                                    const struct hmap *lr_ports,
+                                    const struct hmap *ls_ports,
+                                    const struct chassis_features *features,
+                                    const struct hmap *bfd_connections,
+                                    struct ds *match,
+                                    struct ds *actions,
+                                    struct lflow_data *lflows)
 {
     ovs_assert(od->nbr);
-    build_adm_ctrl_flows_for_lrouter(od, lsi->lflows);
-    build_neigh_learning_flows_for_lrouter(od, lsi->lflows, &lsi->match,
-                                           &lsi->actions, lsi->meter_groups);
-    build_ND_RA_flows_for_lrouter(od, lsi->lflows);
-    build_ip_routing_pre_flows_for_lrouter(od, lsi->lflows);
-    build_static_route_flows_for_lrouter(od, lsi->features,
-                                         lsi->lflows, lsi->lr_ports,
-                                         lsi->bfd_connections);
-    build_mcast_lookup_flows_for_lrouter(od, lsi->lflows, &lsi->match,
-                                         &lsi->actions);
-    build_ingress_policy_flows_for_lrouter(od, lsi->lflows, lsi->lr_ports);
-    build_arp_resolve_flows_for_lrouter(od, lsi->lflows);
-    build_check_pkt_len_flows_for_lrouter(od, lsi->lflows, lsi->lr_ports,
-                                          &lsi->match, &lsi->actions,
-                                          lsi->meter_groups);
-    build_gateway_redirect_flows_for_lrouter(od, lsi->lflows, &lsi->match,
-                                             &lsi->actions);
-    build_arp_request_flows_for_lrouter(od, lsi->lflows, &lsi->match,
-                                        &lsi->actions, lsi->meter_groups);
-    build_misc_local_traffic_drop_flows_for_lrouter(od, lsi->lflows);
-    build_lrouter_arp_nd_for_datapath(od, lsi->lflows, lsi->meter_groups);
-    build_lrouter_nat_defrag_and_lb(od, lsi->lflows, lsi->ls_ports,
-                                    lsi->lr_ports, &lsi->match,
-                                    &lsi->actions, lsi->meter_groups,
-                                    lsi->features);
-    build_lrouter_nat_flows_lb_related(od, lsi->lflows, &lsi->match,
-                                       lsi->features);
-    build_lrouter_nat_flows_ct_lb_related(od, lsi->lflows);
-    build_lrouter_lb_affinity_default_flows(od, lsi->lflows);
+    build_adm_ctrl_flows_for_lrouter(od, lflows);
+    build_neigh_learning_flows_for_lrouter(od, lflows, match,
+                                           actions, meter_groups);
+    build_ND_RA_flows_for_lrouter(od, lflows);
+    build_ip_routing_pre_flows_for_lrouter(od, lflows);
+    build_static_route_flows_for_lrouter(od, features,
+                                         lflows, lr_ports,
+                                         bfd_connections);
+    build_mcast_lookup_flows_for_lrouter(od, lflows, match,
+                                         actions);
+    build_ingress_policy_flows_for_lrouter(od, lflows, lr_ports);
+    build_arp_resolve_flows_for_lrouter(od, lflows);
+    build_check_pkt_len_flows_for_lrouter(od, lflows, lr_ports, match, actions,
+                                          meter_groups);
+    build_gateway_redirect_flows_for_lrouter(od, lflows, match, actions);
+    build_arp_request_flows_for_lrouter(od, lflows, match,
+                                        actions, meter_groups);
+    build_misc_local_traffic_drop_flows_for_lrouter(od, lflows);
+    build_lrouter_arp_nd_for_datapath(od, lflows, meter_groups);
+    build_lrouter_nat_defrag_and_lb(od, lflows, ls_ports,
+                                    lr_ports, match,
+                                    actions, meter_groups,
+                                    features);
+    build_lrouter_nat_flows_lb_related(od, lflows, match, features);
+    build_lrouter_nat_flows_ct_lb_related(od, lflows);
+    build_lrouter_lb_affinity_default_flows(od, lflows);
 }
 
 /* Helper function to combine all lflow generation which is iterated by logical
@@ -17205,37 +17430,38 @@ build_lb_related_iterate_by_lsp(struct ovn_port *op,
  */
 static void
 build_lswitch_and_lrouter_iterate_by_lrp(struct ovn_port *op,
-                                         struct lswitch_flow_build_info *lsi)
+                                         const struct shash *meter_groups,
+                                         struct ds *match,
+                                         struct ds *actions,
+                                         struct lflow_data *lflows)
 {
     ovs_assert(op->nbrp);
-    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,
-                                                &lsi->actions);
-    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, 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,
-                                &lsi->match, &lsi->actions, lsi->meter_groups);
+    build_adm_ctrl_flows_for_lrouter_port(op, lflows, match,
+                                          actions);
+    build_neigh_learning_flows_for_lrouter_port(op, lflows, match,
+                                                actions);
+    build_ip_routing_flows_for_lrp(op, lflows);
+    build_ND_RA_flows_for_lrouter_port(op, lflows, match, actions,
+                                       meter_groups);
+    build_arp_resolve_flows_for_lrp(op, lflows, match, actions);
+    build_egress_delivery_flows_for_lrouter_port(op, lflows, match,
+                                                 actions);
+    build_dhcpv6_reply_flows_for_lrouter_port(op, lflows, match);
+    build_ipv6_input_flows_for_lrouter_port(op, lflows, match, actions,
+                                            meter_groups);
+    build_lrouter_ipv4_ip_input(op, lflows, match, actions, meter_groups);
 }
 
 static void
 build_lb_related_iterate_by_lrp(struct ovn_port *op,
-                                struct lswitch_flow_build_info *lsi)
+                                const struct shash *meter_groups,
+                                struct ds *match,
+                                struct ds *actions,
+                                struct lflow_data *lflows)
 {
     ovs_assert(op->nbrp);
-    build_lrouter_ipv4_ip_input_lb_related(op, lsi->lflows, &lsi->match,
-                                           lsi->meter_groups);
-    build_lrouter_force_snat_flows_op(op, lsi->lflows, &lsi->match,
-                                      &lsi->actions);
+    build_lrouter_ipv4_ip_input_lb_related(op, lflows, match, meter_groups);
+    build_lrouter_force_snat_flows_op(op, lflows, match, actions);
 }
 
 static void *
@@ -17280,7 +17506,10 @@ build_lflows_thread(void *arg)
                     if (stop_parallel_processing()) {
                         return NULL;
                     }
-                    build_lswitch_and_lrouter_iterate_by_lr(od, lsi);
+                    build_lswitch_and_lrouter_iterate_by_lr(
+                        od, lsi->meter_groups, lsi->lr_ports, lsi->ls_ports,
+                        lsi->features, lsi->bfd_connections, &lsi->match,
+                        &lsi->actions, lsi->lflows);
                 }
             }
             for (bnum = control->id;
@@ -17312,8 +17541,12 @@ build_lflows_thread(void *arg)
                     if (stop_parallel_processing()) {
                         return NULL;
                     }
-                    build_lswitch_and_lrouter_iterate_by_lrp(op, lsi);
-                    build_lb_related_iterate_by_lrp(op, lsi);
+                    build_lswitch_and_lrouter_iterate_by_lrp(
+                        op, lsi->meter_groups, &lsi->match, &lsi->actions,
+                        lsi->lflows);
+                    build_lb_related_iterate_by_lrp(
+                        op, lsi->meter_groups, &lsi->match, &lsi->actions,
+                        lsi->lflows);
                 }
             }
             for (bnum = control->id;
@@ -17492,7 +17725,10 @@ build_lswitch_and_lrouter_flows(const struct ovn_datapaths *ls_datapaths,
             build_lswitch_and_lrouter_iterate_by_ls(od, &lsi);
         }
         HMAP_FOR_EACH (od, key_node, &lr_datapaths->datapaths) {
-            build_lswitch_and_lrouter_iterate_by_lr(od, &lsi);
+            build_lswitch_and_lrouter_iterate_by_lr(
+                od, lsi.meter_groups, lsi.lr_ports, lsi.ls_ports,
+                lsi.features, lsi.bfd_connections, &lsi.match,
+                &lsi.actions, lsi.lflows);
         }
         stopwatch_stop(LFLOWS_DATAPATHS_STOPWATCH_NAME, time_msec());
         stopwatch_start(LFLOWS_PORTS_STOPWATCH_NAME, time_msec());
@@ -17506,8 +17742,12 @@ build_lswitch_and_lrouter_flows(const struct ovn_datapaths *ls_datapaths,
                                             &lsi.actions, lsi.lflows);
         }
         HMAP_FOR_EACH (op, key_node, lr_ports) {
-            build_lswitch_and_lrouter_iterate_by_lrp(op, &lsi);
-            build_lb_related_iterate_by_lrp(op, &lsi);
+            build_lswitch_and_lrouter_iterate_by_lrp(op, lsi.meter_groups,
+                                                     &lsi.match,
+                                                     &lsi.actions,
+                                                     lsi.lflows);
+            build_lb_related_iterate_by_lrp(op, lsi.meter_groups, &lsi.match,
+                                            &lsi.actions, lsi.lflows);
         }
         stopwatch_stop(LFLOWS_PORTS_STOPWATCH_NAME, time_msec());
         stopwatch_start(LFLOWS_LBS_STOPWATCH_NAME, time_msec());
@@ -18193,20 +18433,20 @@ bool lflow_handle_northd_port_changes(struct ovsdb_idl_txn *ovnsb_txn,
         struct ds match = DS_EMPTY_INITIALIZER;
         struct ds actions = DS_EMPTY_INITIALIZER;
         if (trk_op->changes & EN_TRACKED_OP_LPORT_CHANGED) {
-            /* We still don't support EN_TRACKED_OP_LPORT_CHANGED for
-             * router ports. */
-            ovs_assert(op->nbsp);
-
             /* unlink old lflows. */
             unlink_lflows(op->od, OBJDEP_TYPE_LPORT, res_name, lflow_data,
                           &op->lflow_dep_mgr);
 
             /* Generate new lflows. */
-            build_lswitch_and_lrouter_iterate_by_lsp(op, lflow_input->ls_ports,
-                                                     lflow_input->lr_ports,
-                                                     lflow_input->meter_groups,
-                                                     &match, &actions,
-                                                     lflow_data);
+            if (op->nbsp) {
+                build_lswitch_and_lrouter_iterate_by_lsp(
+                    op, lflow_input->ls_ports, lflow_input->lr_ports,
+                    lflow_input->meter_groups, &match, &actions, lflow_data);
+            } else {
+                build_lswitch_and_lrouter_iterate_by_lrp(
+                    op, lflow_input->meter_groups, &match, &actions,
+                    lflow_data);
+            }
         }
 
         if (trk_op->changes & EN_TRACKED_OP_LB_CHANGED) {
@@ -18457,6 +18697,70 @@ bool lflow_handle_northd_lb_changes(struct ovsdb_idl_txn *ovnsb_txn,
     return true;
 }
 
+bool
+lflow_handle_northd_od_changes(struct ovsdb_idl_txn *ovnsb_txn,
+                               struct tracked_datapaths *trk_dps,
+                               struct lflow_input *lflow_input,
+                               struct lflow_data *lflow_data)
+{
+    struct ovn_datapath *od;
+    struct hmapx_node *hmapx_node;
+    HMAPX_FOR_EACH (hmapx_node, &trk_dps->crupdated) {
+        od = hmapx_node->data;
+
+        /* We don't support handling logical switches yet. */
+        ovs_assert(od->nbr);
+
+        struct resource_to_objects_node  *res_node =
+            objdep_mgr_find_objs(&od->lflow_dep_mgr, OBJDEP_TYPE_OD,
+                                 od->nbr->name);
+
+        /* unlink old lflows of type OBJDEP_TYPE_OD. */
+        unlink_objres_lflows(res_node, od, lflow_data,
+                             &od->lflow_dep_mgr);
+
+        res_node = objdep_mgr_find_objs(
+            &od->lflow_dep_mgr, OBJDEP_TYPE_LB, od->nbr->name);
+
+        unlink_objres_lflows(res_node, od, lflow_data, &od->lflow_dep_mgr);
+
+        res_node = objdep_mgr_find_objs(
+            &od->lflow_dep_mgr, OBJDEP_TYPE_CT_LB, od->nbr->name);
+        unlink_objres_lflows(res_node, od, lflow_data, &od->lflow_dep_mgr);
+
+        struct ds match = DS_EMPTY_INITIALIZER;
+        struct ds actions = DS_EMPTY_INITIALIZER;
+        build_lswitch_and_lrouter_iterate_by_lr(
+            od, lflow_input->meter_groups, lflow_input->lr_ports,
+            lflow_input->ls_ports, lflow_input->features,
+            lflow_input->bfd_connections, &match,
+            &actions, lflow_data);
+        ds_destroy(&match);
+        ds_destroy(&actions);
+
+        /* Sync the updated flows to SB. */
+        res_node = objdep_mgr_find_objs(&od->lflow_dep_mgr,
+                                        OBJDEP_TYPE_OD,
+                                        od->nbr->name);
+        sync_lflows_from_objres(ovnsb_txn, res_node, lflow_input,
+                                lflow_data, &od->lflow_dep_mgr);
+
+        res_node = objdep_mgr_find_objs(&od->lflow_dep_mgr,
+                                        OBJDEP_TYPE_LB,
+                                        od->nbr->name);
+        sync_lflows_from_objres(ovnsb_txn, res_node, lflow_input,
+                                lflow_data, &od->lflow_dep_mgr);
+
+        res_node = objdep_mgr_find_objs(&od->lflow_dep_mgr,
+                                        OBJDEP_TYPE_CT_LB,
+                                        od->nbr->name);
+        sync_lflows_from_objres(ovnsb_txn, res_node, lflow_input,
+                                lflow_data, &od->lflow_dep_mgr);
+    }
+
+    return true;
+}
+
 /* Each port group in Port_Group table in OVN_Northbound has a corresponding
  * entry in Port_Group table in OVN_Southbound. In OVN_Northbound the entries
  * contains lport uuids, while in OVN_Southbound we store the lport names.
@@ -19341,6 +19645,7 @@ northd_init(struct northd_data *data)
     hmap_init(&data->trk_northd_changes.trk_ovn_ports.deleted);
     hmapx_init(&data->trk_northd_changes.trk_lbs.crupdated);
     hmapx_init(&data->trk_northd_changes.trk_lbs.deleted);
+    hmapx_init(&data->trk_northd_changes.trk_datapaths.crupdated);
 }
 
 void
@@ -19399,6 +19704,7 @@ northd_destroy(struct northd_data *data)
     hmap_destroy(&data->trk_northd_changes.trk_ovn_ports.deleted);
     hmapx_destroy(&data->trk_northd_changes.trk_lbs.crupdated);
     hmapx_destroy(&data->trk_northd_changes.trk_lbs.deleted);
+    hmapx_destroy(&data->trk_northd_changes.trk_datapaths.crupdated);
 }
 
 void
@@ -19495,6 +19801,7 @@ ovnnb_db_run(struct northd_input *input_data,
     build_lb_datapaths(input_data->lbs, input_data->lb_groups,
                        &data->ls_datapaths, &data->lr_datapaths,
                        &data->lb_datapaths_map, &data->lb_group_datapaths_map);
+    build_router_lb_nats(&data->lr_datapaths.datapaths);
     build_ports(ovnsb_txn,
                 input_data->sbrec_port_binding_table,
                 input_data->sbrec_chassis_table,
diff --git a/northd/northd.h b/northd/northd.h
index fc2c083612..a499db00fc 100644
--- a/northd/northd.h
+++ b/northd/northd.h
@@ -113,6 +113,12 @@ struct tracked_ovn_ports {
     struct hmap deleted;
 };
 
+struct tracked_datapaths {
+    /* Tracked created or updated logical switches or
+     * routers. */
+    struct hmapx crupdated;
+};
+
 struct tracked_lb_datapaths {
     /* Tracked created or updated load balancers.
      * hmapx node data is 'struct ovn_lb_datapaths' */
@@ -137,6 +143,10 @@ struct tracked_lb_datapaths {
 struct northd_tracked_data {
     struct tracked_ovn_ports trk_ovn_ports;
     struct tracked_lb_datapaths trk_lbs;
+    struct tracked_datapaths trk_datapaths;
+
+    /* Indicates if any router's NATs changed which were also LB vips. */
+    bool lb_nats_changed;
 };
 
 struct northd_data {
@@ -334,6 +344,9 @@ struct ovn_datapath {
     /* Set of nat external ips on the router. */
     struct sset external_ips;
 
+    /* Set of nat external ips which are lb vips too. */
+    struct sset lb_nats;
+
     /* SNAT IPs owned by the router (shash of 'struct ovn_snat_ip'). */
     struct shash snat_ips;
 
@@ -375,8 +388,10 @@ void ovnsb_db_run(struct ovsdb_idl_txn *ovnnb_txn,
 bool northd_handle_ls_changes(struct ovsdb_idl_txn *,
                               const struct northd_input *,
                               struct northd_data *);
-bool northd_handle_lr_changes(const struct northd_input *,
-                              struct northd_data *);
+bool northd_handle_lr_changes_pre_lb(const struct northd_input *,
+                                     struct northd_data *);
+bool northd_handle_lr_changes_post_lb(const struct northd_input *,
+                                      struct northd_data *);
 void destroy_northd_data_tracked_changes(struct northd_data *);
 void northd_destroy(struct northd_data *data);
 void northd_init(struct northd_data *data);
@@ -393,6 +408,10 @@ bool lflow_handle_northd_lb_changes(struct ovsdb_idl_txn *ovnsb_txn,
                                     struct tracked_lb_datapaths *,
                                     struct lflow_input *lflow_input,
                                     struct lflow_data *lflow_data);
+bool lflow_handle_northd_od_changes(struct ovsdb_idl_txn *ovnsb_txn,
+                                    struct tracked_datapaths *,
+                                    struct lflow_input *lflow_input,
+                                    struct lflow_data *lflow_data);
 bool northd_handle_sb_port_binding_changes(
     const struct sbrec_port_binding_table *, struct hmap *ls_ports,
     struct hmap *lr_ports);
diff --git a/tests/ovn-northd.at b/tests/ovn-northd.at
index 37bfc3e0cf..ec28dea9c8 100644
--- a/tests/ovn-northd.at
+++ b/tests/ovn-northd.at
@@ -10395,3 +10395,205 @@ check test "$node_recompute_ct" -eq "1"
 
 AT_CLEANUP
 ])
+
+OVN_FOR_EACH_NORTHD_NO_HV([
+AT_SETUP([Logical router incremental processing for NAT])
+
+ovn_start
+
+net_add n1
+sim_add hv1
+as hv1
+ovs-vsctl add-br br-phys
+ovn_attach n1 br-phys 192.168.0.11
+
+check_engine_stats() {
+  node=$1
+  recompute=$2
+  compute=$3
+
+  echo "__file__:__line__: Checking engine stats for node $node : recompute - \
+$recompute : compute - $compute"
+
+  node_stat=$(as northd ovn-appctl -t NORTHD_TYPE inc-engine/show-stats $node)
+  # node_stat will be of this format :
+  #     - Node: lflow - recompute: 3 - compute: 0 - abort: 0
+  node_recompute_ct=$(echo $node_stat | cut -d '-' -f2 | cut -d ':' -f2)
+  node_compute_ct=$(echo $node_stat | cut -d '-' -f3 | cut -d ':' -f2)
+
+  if [[ "$recompute" == "norecompute" ]]; then
+    # node should not be recomputed
+    echo "Expecting $node recompute count - $node_recompute_ct to be 0"
+    check test "$node_recompute_ct" -eq "0"
+  else
+    echo "Expecting $node recompute count - $node_recompute_ct not to be 0"
+    check test "$node_recompute_ct" -ne "0"
+  fi
+
+  if [[ "$compute" == "nocompute" ]]; then
+    # node should not be computed
+    echo "Expecting $node compute count - $node_compute_ct to be 0"
+    check test "$node_compute_ct" -eq "0"
+  else
+    echo "Expecting $node compute count - $node_compute_ct not to be 0"
+    check test "$node_compute_ct" -ne "0"
+  fi
+}
+
+ovn-sbctl chassis-add gw1 geneve 127.0.0.1
+
+check ovn-nbctl ls-add sw0
+check ovn-nbctl lsp-add sw0 sw0p1 -- lsp-set-addresses sw0p1 "00:00:20:20:12:01 10.0.0.4"
+
+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 lflow recompute nocompute
+
+# Adding a logical router port should result in recompute
+check as northd ovn-appctl -t NORTHD_TYPE inc-engine/clear-stats
+check ovn-nbctl lrp-add lr0 lr0-sw0 00:00:00:00:ff:01 10.0.0.1/24
+# for northd engine there will be both recompute and compute
+# first it will be recompute to handle lr0-sw0 and then a compute
+# for the SB port binding change.
+check_engine_stats northd recompute compute
+check_engine_stats lflow recompute nocompute
+
+ovn-nbctl lsp-add sw0 sw0-lr0
+ovn-nbctl lsp-set-type sw0-lr0 router
+ovn-nbctl lsp-set-addresses sw0-lr0 00:00:00:00:ff:01
+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 lflow recompute nocompute
+
+ovn-nbctl ls-add public
+ovn-nbctl lrp-add lr0 lr0-public 00:00:20:20:12:13 172.168.0.100/24
+ovn-nbctl lsp-add public public-lr0
+ovn-nbctl lsp-set-type public-lr0 router
+ovn-nbctl lsp-set-addresses public-lr0 router
+ovn-nbctl lsp-set-options public-lr0 router-port=lr0-public
+
+# localnet port
+ovn-nbctl lsp-add public ln-public
+ovn-nbctl lsp-set-type ln-public localnet
+ovn-nbctl lsp-set-addresses ln-public unknown
+ovn-nbctl lsp-set-options ln-public network_name=public
+
+# schedule the gw router port to a chassis. Change the name of the chassis
+ovn-nbctl --wait=hv lrp-set-gateway-chassis lr0-public hv1 20
+
+# Modify a logical router port and it should result in recompute.
+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 lflow recompute nocompute
+
+check as northd ovn-appctl -t NORTHD_TYPE vlog/set dbg
+
+# Do checks for NATs.
+# Add a NAT. This should not result in recompute of both northd and lflow
+# 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 norecompute compute
+check_engine_stats lflow norecompute compute
+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 norecompute compute
+check_engine_stats lflow norecompute compute
+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 norecompute compute
+check_engine_stats lflow norecompute compute
+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 norecompute compute
+check_engine_stats lflow norecompute compute
+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 norecompute compute
+check_engine_stats lflow norecompute compute
+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 norecompute compute
+check_engine_stats lflow norecompute compute
+CHECK_NO_CHANGE_AFTER_RECOMPUTE
+
+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 norecompute compute
+check_engine_stats lflow norecompute compute
+CHECK_NO_CHANGE_AFTER_RECOMPUTE
+
+# Create a load balancer and add the lb vip as NAT
+check ovn-nbctl lb-add lb1 172.168.0.140 10.0.0.20
+check ovn-nbctl lb-add lb2 172.168.0.150:80 10.0.0.40:8080
+check ovn-nbctl lr-lb-add lr0 lb1
+check ovn-nbctl lr-lb-add lr0 lb2
+
+# lflow engine should recompute since the nat ip 172.168.0.140
+# 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 norecompute compute
+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 norecompute compute
+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 norecompute compute
+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 norecompute compute
+check_engine_stats lflow recompute nocompute
+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 norecompute compute
+check_engine_stats lflow norecompute compute
+check_engine_stats sync_to_sb_pb recompute nocompute
+CHECK_NO_CHANGE_AFTER_RECOMPUTE
+
+# Create router Policy
+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 lflow recompute nocompute
+
+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 lflow recompute nocompute
+
+OVN_CLEANUP([hv1])
+AT_CLEANUP
+])
