diff mbox series

[ovs-dev,v1,06/18] northd: Add a new engine 'lr-lb-nat-data' to manage routers' lb data.

Message ID 20231024004434.4133639-1-numans@ovn.org
State Superseded
Headers show
Series lflow incremental processing | expand

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Commit Message

Numan Siddique Oct. 24, 2023, 12:44 a.m. UTC
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 | 635 ++++++++++++++++++++++++++++++++++++
 northd/en-lr-lb-nat-data.h |  90 ++++++
 northd/en-lr-nat.h         |   3 +
 northd/en-sync-sb.c        |  50 +--
 northd/inc-proc-northd.c   |  13 +-
 northd/northd.c            | 644 ++++++++++++-------------------------
 northd/northd.h            | 143 +++++++-
 tests/ovn-northd.at        | 110 +++++--
 11 files changed, 1194 insertions(+), 501 deletions(-)
 create mode 100644 northd/en-lr-lb-nat-data.c
 create mode 100644 northd/en-lr-lb-nat-data.h
diff mbox series

Patch

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..1a3271cc25
--- /dev/null
+++ b/northd/en-lr-lb-nat-data.c
@@ -0,0 +1,635 @@ 
+/*
+ * 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 void lr_lb_nat_data_table_build(struct lr_lb_nat_data_table *,
+                                   const struct lr_nat_table *,
+                                   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 *);
+
+const 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)
+{
+    return lr_lb_nat_data_table_find_(table, nbr);
+}
+
+/* '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.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(
+                input_data.lr_nats, od->nbr);
+            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;
+}
+
+/* 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);
+    }
+}
+
+static void
+lr_lb_nat_data_table_build(struct lr_lb_nat_data_table *table,
+                       const struct lr_nat_table *lr_nats,
+                       const struct hmap *lb_datapaths_map,
+                       const struct hmap *lbgrp_datapaths_map)
+{
+    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_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));
+
+    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..30e76011a8
--- /dev/null
+++ b/northd/en-lr-lb-nat-data.h
@@ -0,0 +1,90 @@ 
+/*
+ * 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;
+};
+
+#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(
+    const struct lr_lb_nat_data_table *, const struct nbrec_logical_router *);
+
+#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 6ed1f5ed52..f264c0cb3a 100644
--- a/northd/en-lr-nat.h
+++ b/northd/en-lr-nat.h
@@ -83,6 +83,9 @@  struct lr_nat_table {
     struct hmap entries; /* Stores struct lr_nat_record. */
 };
 
+#define LR_NAT_TABLE_FOR_EACH(LR_NAT_REC, TABLE) \
+    HMAP_FOR_EACH (LR_NAT_REC, key_node, &(TABLE)->entries)
+
 const struct lr_nat_record * lr_nat_table_find(const struct lr_nat_table *,
                                         const struct nbrec_logical_router *);
 
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 674c461561..30e9278961 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);
@@ -1179,12 +1172,6 @@  ovn_datapath_assign_requested_tnl_id(
     }
 }
 
-static inline size_t
-ods_size(const struct ovn_datapaths *datapaths)
-{
-    return hmap_count(&datapaths->datapaths);
-}
-
 static void
 ods_build_array_index(struct ovn_datapaths *datapaths)
 {
@@ -1317,121 +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
@@ -1456,16 +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));
@@ -1481,9 +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,
+    };
 }
 
 
@@ -1543,8 +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);
@@ -2586,9 +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);
-            }
+           }
         }
     }
 
@@ -2685,7 +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;
@@ -2770,23 +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;
             }
@@ -3857,21 +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 =
@@ -3879,20 +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++) {
@@ -3901,7 +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);
         }
     }
 
@@ -3955,102 +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)
 {
@@ -4072,43 +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,
@@ -4172,8 +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);
@@ -4539,7 +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);
 
@@ -4558,10 +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(lr_lbnats,
+                                                     op->peer->od->nbr);
+                }
                 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;
@@ -4668,7 +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);
 
@@ -4677,14 +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(lr_nats, op->od->nbr);
-        ovs_assert(lrnat_rec);
+        const struct lr_lb_nat_data_record *lr_lbnat_rec =
+            lr_lb_nat_data_table_find(lr_lbnats, op->od->nbr);
+        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,
@@ -4735,17 +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);
@@ -4754,17 +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);
         }
     }
@@ -4772,9 +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);
         }
     }
@@ -5481,20 +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;
@@ -5513,12 +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) {
@@ -5534,14 +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,
@@ -5556,9 +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;
         }
     }
@@ -5810,10 +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);
         }
@@ -5832,10 +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);
             }
@@ -5871,22 +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);
         }
@@ -5914,9 +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);
             }
@@ -9208,7 +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++) {
@@ -9224,7 +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)
 {
@@ -9290,6 +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)
 {
@@ -9305,32 +9010,37 @@  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(lr_lbnats, op->od->nbr);
+        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);
+            }
         }
     }
 
@@ -9380,13 +9090,15 @@  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);
@@ -10447,6 +10159,7 @@  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)
@@ -10462,7 +10175,8 @@  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++) {
@@ -12652,6 +12366,7 @@  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)
@@ -12664,8 +12379,9 @@  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));
 
@@ -12694,8 +12410,9 @@  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));
 
@@ -13407,7 +13124,8 @@  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)) {
@@ -13415,7 +13133,8 @@  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;
     }
 
@@ -13426,19 +13145,28 @@  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(lr_lbnats, router_port->od->nbr);
+
+        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
@@ -13662,33 +13390,36 @@  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.
@@ -13705,6 +13436,7 @@  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);
@@ -13781,8 +13513,8 @@  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. */
@@ -13790,6 +13522,7 @@  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);
@@ -13933,8 +13666,11 @@  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(lr_lbnats,
+                                                         router_port->od->nbr);
                 routable_addresses_to_lflows(lflows, router_port, peer,
-                                             match, actions);
+                                             lr_lbnat_rec, match, actions);
             }
         }
     }
@@ -14654,6 +14390,7 @@  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)
 {
@@ -14778,7 +14515,7 @@  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)",
@@ -14794,7 +14531,7 @@  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)) {
@@ -14896,8 +14633,8 @@  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.
      *
@@ -16036,6 +15773,7 @@  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;
@@ -16119,14 +15857,15 @@  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();
@@ -16139,11 +15878,14 @@  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();
@@ -16162,6 +15904,8 @@  build_lswitch_and_lrouter_iterate_by_lrp(struct ovn_port *op,
                                                               op->od->nbr);
     ovs_assert(lrnet_rec);
 
+    const struct lr_lb_nat_data_record *lr_lbnat_rec =
+        lr_lb_nat_data_table_find(lsi->lr_lbnats, op->od->nbr);
     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,
@@ -16169,15 +15913,15 @@  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);
@@ -16240,6 +15984,7 @@  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,
@@ -16350,6 +16095,7 @@  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,
@@ -16380,6 +16126,7 @@  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;
@@ -16415,6 +16162,7 @@  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,
@@ -16443,6 +16191,7 @@  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);
@@ -16564,6 +16313,7 @@  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,
@@ -17044,6 +16794,7 @@  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);
@@ -17082,6 +16833,7 @@  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 8c9d0f308f..ace9720b95 100644
--- a/northd/northd.h
+++ b/northd/northd.h
@@ -173,6 +173,7 @@  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;
@@ -312,9 +313,6 @@  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;
 
@@ -331,6 +329,125 @@  struct ovn_datapath {
 const struct ovn_datapath *ovn_datapath_find(const struct hmap *datapaths,
                                              const struct uuid *uuid);
 
+static inline size_t
+ods_size(const struct ovn_datapaths *datapaths)
+{
+    return hmap_count(&datapaths->datapaths);
+}
+
+/* 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,
@@ -390,13 +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