diff --git a/ovn/controller/automake.mk b/ovn/controller/automake.mk
index 9c91420..fec9bf1 100644
--- a/ovn/controller/automake.mk
+++ b/ovn/controller/automake.mk
@@ -10,6 +10,8 @@ ovn_controller_ovn_controller_SOURCES = \
 	ovn/controller/lflow.h \
 	ovn/controller/ofctrl.c \
 	ovn/controller/ofctrl.h \
+	ovn/controller/patch.c \
+	ovn/controller/patch.h \
 	ovn/controller/ovn-controller.c \
 	ovn/controller/ovn-controller.h \
 	ovn/controller/physical.c \
diff --git a/ovn/controller/ovn-controller.c b/ovn/controller/ovn-controller.c
index 0371c38..9ba5413 100644
--- a/ovn/controller/ovn-controller.c
+++ b/ovn/controller/ovn-controller.c
@@ -43,6 +43,7 @@
 #include "binding.h"
 #include "chassis.h"
 #include "encaps.h"
+#include "patch.h"
 #include "physical.h"
 #include "lflow.h"
 
@@ -71,7 +72,7 @@ get_chassis(struct ovsdb_idl *ovnsb_idl, const char *chassis_id)
     return chassis_rec;
 }
 
-static const struct ovsrec_bridge *
+const struct ovsrec_bridge *
 get_bridge(struct ovsdb_idl *ovs_idl, const char *br_name)
 {
     const struct ovsrec_bridge *br;
@@ -153,214 +154,6 @@ get_chassis_id(const struct ovsdb_idl *ovs_idl)
     return cfg ? smap_get(&cfg->external_ids, "system-id") : NULL;
 }
 
-static char *
-patch_port_name(const struct ovsrec_bridge *b1, const struct ovsrec_bridge *b2)
-{
-    return xasprintf("patch-%s-to-%s", b1->name, b2->name);
-}
-
-/*
- * Return true if the port is a patch port from b1 to b2
- */
-static bool
-match_patch_port(const struct ovsrec_port *port,
-                 const struct ovsrec_bridge *b1,
-                 const struct ovsrec_bridge *b2)
-{
-    struct ovsrec_interface *iface;
-    size_t i;
-    char *peer_port_name;
-    bool res = false;
-
-    peer_port_name = patch_port_name(b2, b1);
-
-    for (i = 0; i < port->n_interfaces; i++) {
-        iface = port->interfaces[i];
-        if (strcmp(iface->type, "patch")) {
-            continue;
-        }
-        const char *peer;
-        peer = smap_get(&iface->options, "peer");
-        if (peer && !strcmp(peer, peer_port_name)) {
-            res = true;
-            break;
-        }
-    }
-
-    free(peer_port_name);
-
-    return res;
-}
-
-static void
-create_patch_port(struct controller_ctx *ctx,
-                  const char *network,
-                  const struct ovsrec_bridge *b1,
-                  const struct ovsrec_bridge *b2)
-{
-    if (!ctx->ovs_idl_txn) {
-        return;
-    }
-
-    char *port_name = patch_port_name(b1, b2);
-    char *peer_port_name = patch_port_name(b2, b1);
-
-    ovsdb_idl_txn_add_comment(ctx->ovs_idl_txn,
-            "ovn-controller: creating patch port '%s' from '%s' to '%s'",
-            port_name, b1->name, b2->name);
-
-    struct ovsrec_interface *iface;
-    iface = ovsrec_interface_insert(ctx->ovs_idl_txn);
-    ovsrec_interface_set_name(iface, port_name);
-    ovsrec_interface_set_type(iface, "patch");
-    const struct smap options = SMAP_CONST1(&options, "peer", peer_port_name);
-    ovsrec_interface_set_options(iface, &options);
-
-    struct ovsrec_port *port;
-    port = ovsrec_port_insert(ctx->ovs_idl_txn);
-    ovsrec_port_set_name(port, port_name);
-    ovsrec_port_set_interfaces(port, &iface, 1);
-    const struct smap ids = SMAP_CONST1(&ids, "ovn-patch-port", network);
-    ovsrec_port_set_external_ids(port, &ids);
-
-    struct ovsrec_port **ports;
-    ports = xmalloc(sizeof *ports * (b1->n_ports + 1));
-    memcpy(ports, b1->ports, sizeof *ports * b1->n_ports);
-    ports[b1->n_ports] = port;
-    ovsrec_bridge_verify_ports(b1);
-    ovsrec_bridge_set_ports(b1, ports, b1->n_ports + 1);
-
-    free(ports);
-    free(port_name);
-    free(peer_port_name);
-}
-
-static void
-create_patch_ports(struct controller_ctx *ctx,
-                   const char *network,
-                   struct shash *existing_ports,
-                   const struct ovsrec_bridge *b1,
-                   const struct ovsrec_bridge *b2)
-{
-    size_t i;
-
-    for (i = 0; i < b1->n_ports; i++) {
-        if (match_patch_port(b1->ports[i], b1, b2)) {
-            /* Patch port already exists on b1 */
-            shash_find_and_delete(existing_ports, b1->ports[i]->name);
-            break;
-        }
-    }
-    if (i == b1->n_ports) {
-        create_patch_port(ctx, network, b1, b2);
-    }
-}
-
-static void
-init_existing_ports(struct controller_ctx *ctx,
-                    struct shash *existing_ports)
-{
-    const struct ovsrec_port *port;
-
-    OVSREC_PORT_FOR_EACH (port, ctx->ovs_idl) {
-        if (smap_get(&port->external_ids, "ovn-patch-port")) {
-            shash_add(existing_ports, port->name, port);
-        }
-    }
-}
-
-static void
-remove_port(struct controller_ctx *ctx,
-            const struct ovsrec_port *port)
-{
-    const struct ovsrec_bridge *bridge;
-
-    /* We know the port we want to delete, but we have to find the bridge its on
-     * to do so.  Note this only runs on a config change that should be pretty
-     * rare. */
-    OVSREC_BRIDGE_FOR_EACH (bridge, ctx->ovs_idl) {
-        size_t i;
-        for (i = 0; i < bridge->n_ports; i++) {
-            if (bridge->ports[i] != port) {
-                continue;
-            }
-            struct ovsrec_port **new_ports;
-            new_ports = xmemdup(bridge->ports,
-                    sizeof *new_ports * (bridge->n_ports - 1));
-            if (i != bridge->n_ports - 1) {
-                /* Removed port was not last */
-                new_ports[i] = bridge->ports[bridge->n_ports - 1];
-            }
-            ovsrec_bridge_verify_ports(bridge);
-            ovsrec_bridge_set_ports(bridge, new_ports, bridge->n_ports - 1);
-            free(new_ports);
-            ovsrec_port_delete(port);
-            return;
-        }
-    }
-}
-
-static void
-parse_bridge_mappings(struct controller_ctx *ctx,
-                      const struct ovsrec_bridge *br_int,
-                      const char *mappings_cfg)
-{
-    struct shash existing_ports = SHASH_INITIALIZER(&existing_ports);
-    init_existing_ports(ctx, &existing_ports);
-
-    char *cur, *next, *start;
-    next = start = xstrdup(mappings_cfg);
-    while ((cur = strsep(&next, ",")) && *cur) {
-        char *network, *bridge = cur;
-        const struct ovsrec_bridge *ovs_bridge;
-
-        network = strsep(&bridge, ":");
-        if (!bridge || !*network || !*bridge) {
-            VLOG_ERR("Invalid ovn-bridge-mappings configuration: '%s'",
-                    mappings_cfg);
-            break;
-        }
-
-        ovs_bridge = get_bridge(ctx->ovs_idl, bridge);
-        if (!ovs_bridge) {
-            VLOG_WARN("Bridge '%s' not found for network '%s'",
-                    bridge, network);
-            continue;
-        }
-
-        create_patch_ports(ctx, network, &existing_ports, br_int, ovs_bridge);
-        create_patch_ports(ctx, network, &existing_ports, ovs_bridge, br_int);
-    }
-    free(start);
-
-    /* Any ports left in existing_ports are related to configuration that has
-     * been removed, so we should delete the ports now. */
-    struct shash_node *port_node, *port_next_node;
-    SHASH_FOR_EACH_SAFE (port_node, port_next_node, &existing_ports) {
-        struct ovsrec_port *port = port_node->data;
-        shash_delete(&existing_ports, port_node);
-        remove_port(ctx, port);
-    }
-    shash_destroy(&existing_ports);
-}
-
-static void
-init_bridge_mappings(struct controller_ctx *ctx,
-                     const struct ovsrec_bridge *br_int)
-{
-    const char *mappings_cfg = "";
-    const struct ovsrec_open_vswitch *cfg;
-
-    cfg = ovsrec_open_vswitch_first(ctx->ovs_idl);
-    if (cfg) {
-        mappings_cfg = smap_get(&cfg->external_ids, "ovn-bridge-mappings");
-        if (!mappings_cfg) {
-            mappings_cfg = "";
-        }
-    }
-    parse_bridge_mappings(ctx, br_int, mappings_cfg);
-}
-
 /* Retrieves the OVN Southbound remote location from the
  * "external-ids:ovn-remote" key in 'ovs_idl' and returns a copy of it.
  *
@@ -464,7 +257,7 @@ main(int argc, char *argv[])
 
         /* Map bridges to local nets from ovn-bridge-mappings */
         if (br_int) {
-            init_bridge_mappings(&ctx, br_int);
+            patch_run(&ctx, br_int);
         }
 
         if (chassis_id) {
diff --git a/ovn/controller/ovn-controller.h b/ovn/controller/ovn-controller.h
index 9766bc3..b8c48ff 100644
--- a/ovn/controller/ovn-controller.h
+++ b/ovn/controller/ovn-controller.h
@@ -27,6 +27,9 @@ struct controller_ctx {
     struct ovsdb_idl_txn *ovs_idl_txn;
 };
 
+const struct ovsrec_bridge *get_bridge(struct ovsdb_idl *,
+                                       const char *br_name);
+
 const struct sbrec_chassis *get_chassis(struct ovsdb_idl *,
                                         const char *chassis_id);
 
diff --git a/ovn/controller/patch.c b/ovn/controller/patch.c
new file mode 100644
index 0000000..0d192fa
--- /dev/null
+++ b/ovn/controller/patch.c
@@ -0,0 +1,232 @@
+/* Copyright (c) 2015 Nicira, 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 "patch.h"
+
+#include "hash.h"
+#include "lib/vswitch-idl.h"
+#include "openvswitch/vlog.h"
+#include "ovn-controller.h"
+
+VLOG_DEFINE_THIS_MODULE(patch);
+
+static char *
+patch_port_name(const struct ovsrec_bridge *b1, const struct ovsrec_bridge *b2)
+{
+    return xasprintf("patch-%s-to-%s", b1->name, b2->name);
+}
+
+/*
+ * Return true if the port is a patch port from b1 to b2
+ */
+static bool
+match_patch_port(const struct ovsrec_port *port,
+                 const struct ovsrec_bridge *b1,
+                 const struct ovsrec_bridge *b2)
+{
+    struct ovsrec_interface *iface;
+    size_t i;
+    char *peer_port_name;
+    bool res = false;
+
+    peer_port_name = patch_port_name(b2, b1);
+
+    for (i = 0; i < port->n_interfaces; i++) {
+        iface = port->interfaces[i];
+        if (strcmp(iface->type, "patch")) {
+            continue;
+        }
+        const char *peer;
+        peer = smap_get(&iface->options, "peer");
+        if (peer && !strcmp(peer, peer_port_name)) {
+            res = true;
+            break;
+        }
+    }
+
+    free(peer_port_name);
+
+    return res;
+}
+
+static void
+create_patch_port(struct controller_ctx *ctx,
+                  const char *network,
+                  const struct ovsrec_bridge *b1,
+                  const struct ovsrec_bridge *b2)
+{
+    if (!ctx->ovs_idl_txn) {
+        return;
+    }
+
+    char *port_name = patch_port_name(b1, b2);
+    char *peer_port_name = patch_port_name(b2, b1);
+
+    ovsdb_idl_txn_add_comment(ctx->ovs_idl_txn,
+            "ovn-controller: creating patch port '%s' from '%s' to '%s'",
+            port_name, b1->name, b2->name);
+
+    struct ovsrec_interface *iface;
+    iface = ovsrec_interface_insert(ctx->ovs_idl_txn);
+    ovsrec_interface_set_name(iface, port_name);
+    ovsrec_interface_set_type(iface, "patch");
+    const struct smap options = SMAP_CONST1(&options, "peer", peer_port_name);
+    ovsrec_interface_set_options(iface, &options);
+
+    struct ovsrec_port *port;
+    port = ovsrec_port_insert(ctx->ovs_idl_txn);
+    ovsrec_port_set_name(port, port_name);
+    ovsrec_port_set_interfaces(port, &iface, 1);
+    const struct smap ids = SMAP_CONST1(&ids, "ovn-patch-port", network);
+    ovsrec_port_set_external_ids(port, &ids);
+
+    struct ovsrec_port **ports;
+    ports = xmalloc(sizeof *ports * (b1->n_ports + 1));
+    memcpy(ports, b1->ports, sizeof *ports * b1->n_ports);
+    ports[b1->n_ports] = port;
+    ovsrec_bridge_verify_ports(b1);
+    ovsrec_bridge_set_ports(b1, ports, b1->n_ports + 1);
+
+    free(ports);
+    free(port_name);
+    free(peer_port_name);
+}
+
+static void
+create_patch_ports(struct controller_ctx *ctx,
+                   const char *network,
+                   struct shash *existing_ports,
+                   const struct ovsrec_bridge *b1,
+                   const struct ovsrec_bridge *b2)
+{
+    size_t i;
+
+    for (i = 0; i < b1->n_ports; i++) {
+        if (match_patch_port(b1->ports[i], b1, b2)) {
+            /* Patch port already exists on b1 */
+            shash_find_and_delete(existing_ports, b1->ports[i]->name);
+            break;
+        }
+    }
+    if (i == b1->n_ports) {
+        create_patch_port(ctx, network, b1, b2);
+    }
+}
+
+static void
+init_existing_ports(struct controller_ctx *ctx,
+                    struct shash *existing_ports)
+{
+    const struct ovsrec_port *port;
+
+    OVSREC_PORT_FOR_EACH (port, ctx->ovs_idl) {
+        if (smap_get(&port->external_ids, "ovn-patch-port")) {
+            shash_add(existing_ports, port->name, port);
+        }
+    }
+}
+
+static void
+remove_port(struct controller_ctx *ctx,
+            const struct ovsrec_port *port)
+{
+    const struct ovsrec_bridge *bridge;
+
+    /* We know the port we want to delete, but we have to find the bridge its
+     * on to do so.  Note this only runs on a config change that should be
+     * pretty rare. */
+    OVSREC_BRIDGE_FOR_EACH (bridge, ctx->ovs_idl) {
+        size_t i;
+        for (i = 0; i < bridge->n_ports; i++) {
+            if (bridge->ports[i] != port) {
+                continue;
+            }
+            struct ovsrec_port **new_ports;
+            new_ports = xmemdup(bridge->ports,
+                    sizeof *new_ports * (bridge->n_ports - 1));
+            if (i != bridge->n_ports - 1) {
+                /* Removed port was not last */
+                new_ports[i] = bridge->ports[bridge->n_ports - 1];
+            }
+            ovsrec_bridge_verify_ports(bridge);
+            ovsrec_bridge_set_ports(bridge, new_ports, bridge->n_ports - 1);
+            free(new_ports);
+            ovsrec_port_delete(port);
+            return;
+        }
+    }
+}
+
+static void
+parse_bridge_mappings(struct controller_ctx *ctx,
+                      const struct ovsrec_bridge *br_int,
+                      const char *mappings_cfg)
+{
+    struct shash existing_ports = SHASH_INITIALIZER(&existing_ports);
+    init_existing_ports(ctx, &existing_ports);
+
+    char *cur, *next, *start;
+    next = start = xstrdup(mappings_cfg);
+    while ((cur = strsep(&next, ",")) && *cur) {
+        char *network, *bridge = cur;
+        const struct ovsrec_bridge *ovs_bridge;
+
+        network = strsep(&bridge, ":");
+        if (!bridge || !*network || !*bridge) {
+            VLOG_ERR("Invalid ovn-bridge-mappings configuration: '%s'",
+                    mappings_cfg);
+            break;
+        }
+
+        ovs_bridge = get_bridge(ctx->ovs_idl, bridge);
+        if (!ovs_bridge) {
+            VLOG_WARN("Bridge '%s' not found for network '%s'",
+                    bridge, network);
+            continue;
+        }
+
+        create_patch_ports(ctx, network, &existing_ports, br_int, ovs_bridge);
+        create_patch_ports(ctx, network, &existing_ports, ovs_bridge, br_int);
+    }
+    free(start);
+
+    /* Any ports left in existing_ports are related to configuration that has
+     * been removed, so we should delete the ports now. */
+    struct shash_node *port_node, *port_next_node;
+    SHASH_FOR_EACH_SAFE (port_node, port_next_node, &existing_ports) {
+        struct ovsrec_port *port = port_node->data;
+        shash_delete(&existing_ports, port_node);
+        remove_port(ctx, port);
+    }
+    shash_destroy(&existing_ports);
+}
+
+void
+patch_run(struct controller_ctx *ctx, const struct ovsrec_bridge *br_int)
+{
+    const char *mappings_cfg = "";
+    const struct ovsrec_open_vswitch *cfg;
+
+    cfg = ovsrec_open_vswitch_first(ctx->ovs_idl);
+    if (cfg) {
+        mappings_cfg = smap_get(&cfg->external_ids, "ovn-bridge-mappings");
+        if (!mappings_cfg) {
+            mappings_cfg = "";
+        }
+    }
+    parse_bridge_mappings(ctx, br_int, mappings_cfg);
+}
diff --git a/ovn/controller/ovn-controller.h b/ovn/controller/patch.h
similarity index 59%
copy from ovn/controller/ovn-controller.h
copy to ovn/controller/patch.h
index 9766bc3..f7db2fc 100644
--- a/ovn/controller/ovn-controller.h
+++ b/ovn/controller/patch.h
@@ -13,21 +13,18 @@
  * limitations under the License.
  */
 
+#ifndef OVN_PATCH_H
+#define OVN_PATCH_H 1
 
-#ifndef OVN_CONTROLLER_H
-#define OVN_CONTROLLER_H 1
-
-#include "ovn/lib/ovn-sb-idl.h"
-
-struct controller_ctx {
-    struct ovsdb_idl *ovnsb_idl;
-    struct ovsdb_idl_txn *ovnsb_idl_txn;
+/* Patch Ports
+ * ===========
+ *
+ * This module adds and removes patch ports between the integration bridge and
+ * physical bridges, as directed by other-config:ovn-bridge-mappings. */
 
-    struct ovsdb_idl *ovs_idl;
-    struct ovsdb_idl_txn *ovs_idl_txn;
-};
+struct controller_ctx;
+struct ovsrec_bridge;
 
-const struct sbrec_chassis *get_chassis(struct ovsdb_idl *,
-                                        const char *chassis_id);
+void patch_run(struct controller_ctx *, const struct ovsrec_bridge *br_int);
 
-#endif /* ovn/ovn-controller.h */
+#endif /* ovn/patch.h */
