diff mbox series

[ovs-dev,4/5] lb: Support using templates.

Message ID 166759963681.514148.12853808964227142023.stgit@dceara.remote.csb
State Not Applicable
Headers show
Series Add OVN component templates. | expand

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Commit Message

Dumitru Ceara Nov. 4, 2022, 10:07 p.m. UTC
Allow the CMS to configure template LBs.  The following configurations are
supported:
- VIPs of the form: ^vip_variable[:^port_variable|:port]
- Backends of the form:
  ^backendip_variable1[:^port_variable1|:port],^backendip_variable2[:^port_variable2|:port]
  OR
  ^backends_variable1,^backends_variable2

The CMS needs to provide a bit more information than with non-template load
balancers and must explicitly specify the address family to be used.

There is currently no support for template load balancers with
options:add_route=true set.  That is because ovn-northd does not
instantiate template variables.  While this is a limitation in a way, its
impact is not huge.  The load balancer 'add_route' option was added as a
way to make the CMS life easier and to avoid having to explicitly add a
route for the VIP.  The CMS can still achieve the same logical topology by
explicitly adding the VIP route.

Template load balancers don't support the "reachable" neighbor-responder
mode.  Instead the CMS can explicitly configure the responder mode to
either "all" or "none".

To properly handle template updates in ovn-controller we also add a
Chassis_Template_Var <- LB reference in ovn-controller.  This way, when
a Chassis_Template_Var changes value all load balancers that refer to
it will also get updated.

Signed-off-by: Dumitru Ceara <dceara@redhat.com>
---
V2:
- Fix GCC build due to missing explicit return.
- Fix ls_in_pre_stateful flows due to using wrong lb field.
- Use new lexer_parse_template_string().
- Changed lb_handle_changed_ref() signature to return bool.
- Update documentation with info about responder mode=none, LB template
  supported formats, lb explicit address family requirements.
- Squashed the template LB patches into a single one
- Added more tests.
- Squashed the system tests patch into this one.
---
 controller/lflow.c          |  118 +++++++++--
 controller/lflow.h          |    7 +
 controller/ovn-controller.c |   67 +++++-
 lib/lb.c                    |  457 ++++++++++++++++++++++++++++++++++++++-----
 lib/lb.h                    |   40 +++-
 lib/ovn-util.c              |    3 
 northd/northd.c             |   89 ++++----
 ovn-nb.xml                  |   53 +++++
 tests/ovn-nbctl.at          |   23 +-
 tests/ovn-northd.at         |    7 +
 tests/ovn.at                |  131 ++++++++++++
 tests/system-ovn.at         |  183 +++++++++++++++++
 utilities/ovn-nbctl.c       |  122 ++++++-----
 13 files changed, 1071 insertions(+), 229 deletions(-)
diff mbox series

Patch

diff --git a/controller/lflow.c b/controller/lflow.c
index fc4371d0df..7f880bd62b 100644
--- a/controller/lflow.c
+++ b/controller/lflow.c
@@ -97,6 +97,15 @@  consider_logical_flow(const struct sbrec_logical_flow *lflow,
                       struct lflow_ctx_in *l_ctx_in,
                       struct lflow_ctx_out *l_ctx_out);
 
+static void
+consider_lb_hairpin_flows(struct objdep_mgr *mgr,
+                          const struct sbrec_load_balancer *sbrec_lb,
+                          const struct hmap *local_datapaths,
+                          const struct smap *template_vars,
+                          bool use_ct_mark,
+                          struct ovn_desired_flow_table *flow_table,
+                          struct simap *ids);
+
 static void add_port_sec_flows(const struct shash *binding_lports,
                                const struct sbrec_chassis *,
                                struct ovn_desired_flow_table *);
@@ -223,7 +232,7 @@  lflow_handle_changed_flows(struct lflow_ctx_in *l_ctx_in,
         UUIDSET_INITIALIZER(&flood_remove_nodes);
     SBREC_LOGICAL_FLOW_TABLE_FOR_EACH_TRACKED (lflow,
                                                l_ctx_in->logical_flow_table) {
-        if (uuidset_find(l_ctx_out->lflows_processed, &lflow->header_.uuid)) {
+        if (uuidset_find(l_ctx_out->objs_processed, &lflow->header_.uuid)) {
             VLOG_DBG("lflow "UUID_FMT"has been processed, skip.",
                      UUID_ARGS(&lflow->header_.uuid));
             continue;
@@ -253,14 +262,14 @@  lflow_handle_changed_flows(struct lflow_ctx_in *l_ctx_in,
                      UUID_ARGS(&lflow->header_.uuid));
 
             /* For the extra lflows that need to be reprocessed because of the
-             * flood remove, remove it from lflows_processed. */
+             * flood remove, remove it from objs_processed. */
             struct uuidset_node *unode =
-                uuidset_find(l_ctx_out->lflows_processed,
+                uuidset_find(l_ctx_out->objs_processed,
                              &lflow->header_.uuid);
             if (unode) {
                 VLOG_DBG("lflow "UUID_FMT"has been processed, now reprocess.",
                          UUID_ARGS(&lflow->header_.uuid));
-                uuidset_delete(l_ctx_out->lflows_processed, unode);
+                uuidset_delete(l_ctx_out->objs_processed, unode);
             }
 
             consider_logical_flow(lflow, false, l_ctx_in, l_ctx_out);
@@ -677,7 +686,7 @@  lflow_handle_addr_set_update(const char *as_name,
     struct object_to_resources_list_node *resource_list_node;
     RESOURCE_FOR_EACH_OBJ (resource_list_node, resource_node) {
         const struct uuid *obj_uuid = &resource_list_node->obj_uuid;
-        if (uuidset_find(l_ctx_out->lflows_processed, obj_uuid)) {
+        if (uuidset_find(l_ctx_out->objs_processed, obj_uuid)) {
             VLOG_DBG("lflow "UUID_FMT"has been processed, skip.",
                      UUID_ARGS(obj_uuid));
             continue;
@@ -767,13 +776,13 @@  lflow_handle_changed_ref(enum objdep_type type, const char *res_name,
         }
 
         /* For the extra lflows that need to be reprocessed because of the
-         * flood remove, remove it from lflows_processed. */
+         * flood remove, remove it from objs_processed. */
         struct uuidset_node *unode =
-            uuidset_find(l_ctx_out->lflows_processed, &lflow->header_.uuid);
+            uuidset_find(l_ctx_out->objs_processed, &lflow->header_.uuid);
         if (unode) {
             VLOG_DBG("lflow "UUID_FMT"has been processed, now reprocess.",
                      UUID_ARGS(&lflow->header_.uuid));
-            uuidset_delete(l_ctx_out->lflows_processed, unode);
+            uuidset_delete(l_ctx_out->objs_processed, unode);
         }
 
         consider_logical_flow(lflow, false, l_ctx_in, l_ctx_out);
@@ -782,6 +791,43 @@  lflow_handle_changed_ref(enum objdep_type type, const char *res_name,
     return true;
 }
 
+bool
+lb_handle_changed_ref(enum objdep_type type, const char *res_name,
+                      struct ovs_list *objs_todo,
+                      const void *in_arg, void *out_arg)
+{
+    struct lflow_ctx_in *l_ctx_in = CONST_CAST(struct lflow_ctx_in *, in_arg);
+    struct lflow_ctx_out *l_ctx_out = out_arg;
+
+    struct object_to_resources_list_node *resource_lb_uuid;
+    LIST_FOR_EACH_POP (resource_lb_uuid, list_node, objs_todo) {
+        VLOG_DBG("Reprocess LB "UUID_FMT" for resource type: %s, name: %s",
+                 UUID_ARGS(&resource_lb_uuid->obj_uuid),
+                 objdep_type_name(type), res_name);
+
+        const struct sbrec_load_balancer *lb =
+            sbrec_load_balancer_table_get_for_uuid(
+                l_ctx_in->lb_table, &resource_lb_uuid->obj_uuid);
+        if (!lb) {
+            VLOG_DBG("Failed to find LB "UUID_FMT" referred by: %s",
+                     UUID_ARGS(&resource_lb_uuid->obj_uuid), res_name);
+        } else {
+            ofctrl_remove_flows(l_ctx_out->flow_table,
+                                &resource_lb_uuid->obj_uuid);
+
+            consider_lb_hairpin_flows(l_ctx_out->lb_deps_mgr, lb,
+                                      l_ctx_in->local_datapaths,
+                                      l_ctx_in->template_vars,
+                                      l_ctx_in->lb_hairpin_use_ct_mark,
+                                      l_ctx_out->flow_table,
+                                      l_ctx_out->hairpin_lb_ids);
+        }
+
+        free(resource_lb_uuid);
+    }
+    return true;
+}
+
 static void
 lflow_parse_ctrl_meter(const struct sbrec_logical_flow *lflow,
                        struct ovn_extend_table *meter_table,
@@ -1263,9 +1309,9 @@  consider_logical_flow(const struct sbrec_logical_flow *lflow,
 
     COVERAGE_INC(consider_logical_flow);
     if (!is_recompute) {
-        ovs_assert(!uuidset_find(l_ctx_out->lflows_processed,
+        ovs_assert(!uuidset_find(l_ctx_out->objs_processed,
                                  &lflow->header_.uuid));
-        uuidset_insert(l_ctx_out->lflows_processed, &lflow->header_.uuid);
+        uuidset_insert(l_ctx_out->objs_processed, &lflow->header_.uuid);
     }
 
     if (dp) {
@@ -2005,8 +2051,11 @@  add_lb_ct_snat_hairpin_flows(struct ovn_controller_lb *lb,
 }
 
 static void
-consider_lb_hairpin_flows(const struct sbrec_load_balancer *sbrec_lb,
-                          const struct hmap *local_datapaths, bool use_ct_mark,
+consider_lb_hairpin_flows(struct objdep_mgr *mgr,
+                          const struct sbrec_load_balancer *sbrec_lb,
+                          const struct hmap *local_datapaths,
+                          const struct smap *template_vars,
+                          bool use_ct_mark,
                           struct ovn_desired_flow_table *flow_table,
                           struct simap *ids)
 {
@@ -2042,7 +2091,9 @@  consider_lb_hairpin_flows(const struct sbrec_load_balancer *sbrec_lb,
         return;
     }
 
-    struct ovn_controller_lb *lb = ovn_controller_lb_create(sbrec_lb);
+    struct sset template_vars_ref = SSET_INITIALIZER(&template_vars_ref);
+    struct ovn_controller_lb *lb =
+        ovn_controller_lb_create(sbrec_lb, template_vars, &template_vars_ref);
     uint8_t lb_proto = IPPROTO_TCP;
     if (lb->slb->protocol && lb->slb->protocol[0]) {
         if (!strcmp(lb->slb->protocol, "udp")) {
@@ -2052,6 +2103,11 @@  consider_lb_hairpin_flows(const struct sbrec_load_balancer *sbrec_lb,
         }
     }
 
+    const char *tv_name;
+    SSET_FOR_EACH (tv_name, &template_vars_ref) {
+        objdep_mgr_add(mgr, OBJDEP_TYPE_TEMPLATE, tv_name,
+                       &sbrec_lb->header_.uuid);
+    }
     for (i = 0; i < lb->n_vips; i++) {
         struct ovn_lb_vip *lb_vip = &lb->vips[i];
 
@@ -2066,13 +2122,17 @@  consider_lb_hairpin_flows(const struct sbrec_load_balancer *sbrec_lb,
     add_lb_ct_snat_hairpin_flows(lb, id, lb_proto, flow_table);
 
     ovn_controller_lb_destroy(lb);
+    sset_destroy(&template_vars_ref);
 }
 
 /* Adds OpenFlow flows to flow tables for each Load balancer VIPs and
  * backends to handle the load balanced hairpin traffic. */
 static void
-add_lb_hairpin_flows(const struct sbrec_load_balancer_table *lb_table,
-                     const struct hmap *local_datapaths, bool use_ct_mark,
+add_lb_hairpin_flows(struct objdep_mgr *mgr,
+                     const struct sbrec_load_balancer_table *lb_table,
+                     const struct hmap *local_datapaths,
+                     const struct smap *template_vars,
+                     bool use_ct_mark,
                      struct ovn_desired_flow_table *flow_table,
                      struct simap *ids,
                      struct id_pool *pool)
@@ -2095,8 +2155,8 @@  add_lb_hairpin_flows(const struct sbrec_load_balancer_table *lb_table,
             ovs_assert(id_pool_alloc_id(pool, &id));
             simap_put(ids, lb->name, id);
         }
-        consider_lb_hairpin_flows(lb, local_datapaths, use_ct_mark, flow_table,
-                                  ids);
+        consider_lb_hairpin_flows(mgr, lb, local_datapaths, template_vars,
+                                  use_ct_mark, flow_table, ids);
     }
 }
 
@@ -2232,7 +2292,9 @@  lflow_run(struct lflow_ctx_in *l_ctx_in, struct lflow_ctx_out *l_ctx_out)
                        l_ctx_in->static_mac_binding_table,
                        l_ctx_in->local_datapaths,
                        l_ctx_out->flow_table);
-    add_lb_hairpin_flows(l_ctx_in->lb_table, l_ctx_in->local_datapaths,
+    add_lb_hairpin_flows(l_ctx_out->lb_deps_mgr, l_ctx_in->lb_table,
+                         l_ctx_in->local_datapaths,
+                         l_ctx_in->template_vars,
                          l_ctx_in->lb_hairpin_use_ct_mark,
                          l_ctx_out->flow_table,
                          l_ctx_out->hairpin_lb_ids,
@@ -2283,10 +2345,10 @@  lflow_add_flows_for_datapath(const struct sbrec_datapath_binding *dp,
     const struct sbrec_logical_flow *lflow;
     SBREC_LOGICAL_FLOW_FOR_EACH_EQUAL (
         lflow, lf_row, l_ctx_in->sbrec_logical_flow_by_logical_datapath) {
-        if (uuidset_find(l_ctx_out->lflows_processed, &lflow->header_.uuid)) {
+        if (uuidset_find(l_ctx_out->objs_processed, &lflow->header_.uuid)) {
             continue;
         }
-        uuidset_insert(l_ctx_out->lflows_processed, &lflow->header_.uuid);
+        uuidset_insert(l_ctx_out->objs_processed, &lflow->header_.uuid);
         consider_logical_flow__(lflow, dp, l_ctx_in, l_ctx_out);
     }
     sbrec_logical_flow_index_destroy_row(lf_row);
@@ -2311,7 +2373,7 @@  lflow_add_flows_for_datapath(const struct sbrec_datapath_binding *dp,
         sbrec_logical_flow_index_set_logical_dp_group(lf_row, ldpg);
         SBREC_LOGICAL_FLOW_FOR_EACH_EQUAL (
             lflow, lf_row, l_ctx_in->sbrec_logical_flow_by_logical_dp_group) {
-            if (uuidset_find(l_ctx_out->lflows_processed,
+            if (uuidset_find(l_ctx_out->objs_processed,
                              &lflow->header_.uuid)) {
                 continue;
             }
@@ -2363,7 +2425,9 @@  lflow_add_flows_for_datapath(const struct sbrec_datapath_binding *dp,
     /* Add load balancer hairpin flows if the datapath has any load balancers
      * associated. */
     for (size_t i = 0; i < n_dp_lbs; i++) {
-        consider_lb_hairpin_flows(dp_lbs[i], l_ctx_in->local_datapaths,
+        consider_lb_hairpin_flows(l_ctx_out->lb_deps_mgr, dp_lbs[i],
+                                  l_ctx_in->local_datapaths,
+                                  l_ctx_in->template_vars,
                                   l_ctx_in->lb_hairpin_use_ct_mark,
                                   l_ctx_out->flow_table,
                                   l_ctx_out->hairpin_lb_ids);
@@ -2385,7 +2449,7 @@  lflow_handle_flows_for_lport(const struct sbrec_port_binding *pb,
                                   OBJDEP_TYPE_PORTBINDING,
                                   pb->logical_port,
                                   lflow_handle_changed_ref,
-                                  l_ctx_out->lflows_processed,
+                                  l_ctx_out->objs_processed,
                                   l_ctx_in, l_ctx_out, &changed)) {
         return false;
     }
@@ -2424,7 +2488,7 @@  lflow_handle_changed_port_bindings(struct lflow_ctx_in *l_ctx_in,
                                       OBJDEP_TYPE_PORTBINDING,
                                       pb->logical_port,
                                       lflow_handle_changed_ref,
-                                      l_ctx_out->lflows_processed,
+                                      l_ctx_out->objs_processed,
                                       l_ctx_in, l_ctx_out, &changed)) {
             ret = false;
             break;
@@ -2451,7 +2515,7 @@  lflow_handle_changed_mc_groups(struct lflow_ctx_in *l_ctx_in,
         if (!objdep_mgr_handle_change(l_ctx_out->lflow_deps_mgr,
                                       OBJDEP_TYPE_MC_GROUP, ds_cstr(&mg_key),
                                       lflow_handle_changed_ref,
-                                      l_ctx_out->lflows_processed,
+                                      l_ctx_out->objs_processed,
                                       l_ctx_in, l_ctx_out, &changed)) {
             ret = false;
             break;
@@ -2505,7 +2569,9 @@  lflow_handle_changed_lbs(struct lflow_ctx_in *l_ctx_in,
 
         VLOG_DBG("Add load balancer hairpin flows for "UUID_FMT,
                  UUID_ARGS(&lb->header_.uuid));
-        consider_lb_hairpin_flows(lb, l_ctx_in->local_datapaths,
+        consider_lb_hairpin_flows(l_ctx_out->lb_deps_mgr, lb,
+                                  l_ctx_in->local_datapaths,
+                                  l_ctx_in->template_vars,
                                   l_ctx_in->lb_hairpin_use_ct_mark,
                                   l_ctx_out->flow_table,
                                   l_ctx_out->hairpin_lb_ids);
diff --git a/controller/lflow.h b/controller/lflow.h
index 9a7079f99e..069b5d795f 100644
--- a/controller/lflow.h
+++ b/controller/lflow.h
@@ -121,9 +121,10 @@  struct lflow_ctx_out {
     struct ovn_extend_table *group_table;
     struct ovn_extend_table *meter_table;
     struct objdep_mgr *lflow_deps_mgr;
+    struct objdep_mgr *lb_deps_mgr;
     struct lflow_cache *lflow_cache;
     struct conj_ids *conj_ids;
-    struct uuidset *lflows_processed;
+    struct uuidset *objs_processed;
     struct simap *hairpin_lb_ids;
     struct id_pool *hairpin_id_pool;
 };
@@ -173,4 +174,8 @@  bool lflow_handle_changed_mc_groups(struct lflow_ctx_in *,
                                     struct lflow_ctx_out *);
 bool lflow_handle_changed_port_bindings(struct lflow_ctx_in *,
                                         struct lflow_ctx_out *);
+
+bool lb_handle_changed_ref(enum objdep_type type, const char *res_name,
+                           struct ovs_list *objs_todo,
+                           const void *in_arg, void *out_arg);
 #endif /* controller/lflow.h */
diff --git a/controller/ovn-controller.c b/controller/ovn-controller.c
index c374bd0f33..f0be783ee6 100644
--- a/controller/ovn-controller.c
+++ b/controller/ovn-controller.c
@@ -2769,13 +2769,15 @@  struct ed_type_lflow_output {
     struct ovn_extend_table meter_table;
     /* lflow <-> resource cross reference */
     struct objdep_mgr lflow_deps_mgr;;
+    /* load balancer <-> resource cross reference */
+    struct objdep_mgr lb_deps_mgr;
     /* conjunciton ID usage information of lflows */
     struct conj_ids conj_ids;
 
-    /* lflows processed in the current engine execution.
+    /* objects (lflows and lbs) processed in the current engine execution.
      * Cleared by en_lflow_output_clear_tracked_data before each engine
      * execution. */
-    struct uuidset lflows_processed;
+    struct uuidset objs_processed;
 
     /* Data which is persistent and not cleared during
      * full recompute. */
@@ -2932,8 +2934,9 @@  init_lflow_ctx(struct engine_node *node,
     l_ctx_out->group_table = &fo->group_table;
     l_ctx_out->meter_table = &fo->meter_table;
     l_ctx_out->lflow_deps_mgr = &fo->lflow_deps_mgr;
+    l_ctx_out->lb_deps_mgr = &fo->lb_deps_mgr;
     l_ctx_out->conj_ids = &fo->conj_ids;
-    l_ctx_out->lflows_processed = &fo->lflows_processed;
+    l_ctx_out->objs_processed = &fo->objs_processed;
     l_ctx_out->lflow_cache = fo->pd.lflow_cache;
     l_ctx_out->hairpin_id_pool = fo->hd.pool;
     l_ctx_out->hairpin_lb_ids = &fo->hd.ids;
@@ -2948,8 +2951,9 @@  en_lflow_output_init(struct engine_node *node OVS_UNUSED,
     ovn_extend_table_init(&data->group_table);
     ovn_extend_table_init(&data->meter_table);
     objdep_mgr_init(&data->lflow_deps_mgr);
+    objdep_mgr_init(&data->lb_deps_mgr);
     lflow_conj_ids_init(&data->conj_ids);
-    uuidset_init(&data->lflows_processed);
+    uuidset_init(&data->objs_processed);
     simap_init(&data->hd.ids);
     data->hd.pool = id_pool_create(1, UINT32_MAX - 1);
     nd_ra_opts_init(&data->nd_ra_opts);
@@ -2961,7 +2965,7 @@  static void
 en_lflow_output_clear_tracked_data(void *data)
 {
     struct ed_type_lflow_output *flow_output_data = data;
-    uuidset_clear(&flow_output_data->lflows_processed);
+    uuidset_clear(&flow_output_data->objs_processed);
 }
 
 static void
@@ -2972,8 +2976,9 @@  en_lflow_output_cleanup(void *data)
     ovn_extend_table_destroy(&flow_output_data->group_table);
     ovn_extend_table_destroy(&flow_output_data->meter_table);
     objdep_mgr_destroy(&flow_output_data->lflow_deps_mgr);
+    objdep_mgr_destroy(&flow_output_data->lb_deps_mgr);
     lflow_conj_ids_destroy(&flow_output_data->conj_ids);
-    uuidset_destroy(&flow_output_data->lflows_processed);
+    uuidset_destroy(&flow_output_data->objs_processed);
     lflow_cache_destroy(flow_output_data->pd.lflow_cache);
     simap_destroy(&flow_output_data->hd.ids);
     id_pool_destroy(flow_output_data->hd.pool);
@@ -3008,6 +3013,7 @@  en_lflow_output_run(struct engine_node *node, void *data)
     struct ovn_extend_table *group_table = &fo->group_table;
     struct ovn_extend_table *meter_table = &fo->meter_table;
     struct objdep_mgr *lflow_deps_mgr = &fo->lflow_deps_mgr;
+    struct objdep_mgr *lb_deps_mgr = &fo->lb_deps_mgr;
 
     static bool first_run = true;
     if (first_run) {
@@ -3017,6 +3023,7 @@  en_lflow_output_run(struct engine_node *node, void *data)
         ovn_extend_table_clear(group_table, false /* desired */);
         ovn_extend_table_clear(meter_table, false /* desired */);
         objdep_mgr_clear(lflow_deps_mgr);
+        objdep_mgr_clear(lb_deps_mgr);
         lflow_conj_ids_clear(&fo->conj_ids);
     }
 
@@ -3150,7 +3157,7 @@  lflow_output_addr_sets_handler(struct engine_node *node, void *data)
         if (!objdep_mgr_handle_change(l_ctx_out.lflow_deps_mgr,
                                       OBJDEP_TYPE_ADDRSET, ref_name,
                                       lflow_handle_changed_ref,
-                                      l_ctx_out.lflows_processed,
+                                      l_ctx_out.objs_processed,
                                       &l_ctx_in, &l_ctx_out, &changed)) {
             return false;
         }
@@ -3169,7 +3176,7 @@  lflow_output_addr_sets_handler(struct engine_node *node, void *data)
                                           OBJDEP_TYPE_ADDRSET,
                                           shash_node->name,
                                           lflow_handle_changed_ref,
-                                          l_ctx_out.lflows_processed,
+                                          l_ctx_out.objs_processed,
                                           &l_ctx_in, &l_ctx_out, &changed)) {
                 return false;
             }
@@ -3182,7 +3189,7 @@  lflow_output_addr_sets_handler(struct engine_node *node, void *data)
         if (!objdep_mgr_handle_change(l_ctx_out.lflow_deps_mgr,
                                       OBJDEP_TYPE_ADDRSET, ref_name,
                                       lflow_handle_changed_ref,
-                                      l_ctx_out.lflows_processed,
+                                      l_ctx_out.objs_processed,
                                       &l_ctx_in, &l_ctx_out, &changed)) {
             return false;
         }
@@ -3217,7 +3224,7 @@  lflow_output_port_groups_handler(struct engine_node *node, void *data)
         if (!objdep_mgr_handle_change(l_ctx_out.lflow_deps_mgr,
                                       OBJDEP_TYPE_PORTGROUP, ref_name,
                                       lflow_handle_changed_ref,
-                                      l_ctx_out.lflows_processed,
+                                      l_ctx_out.objs_processed,
                                       &l_ctx_in, &l_ctx_out, &changed)) {
             return false;
         }
@@ -3229,7 +3236,7 @@  lflow_output_port_groups_handler(struct engine_node *node, void *data)
         if (!objdep_mgr_handle_change(l_ctx_out.lflow_deps_mgr,
                                       OBJDEP_TYPE_PORTGROUP, ref_name,
                                       lflow_handle_changed_ref,
-                                      l_ctx_out.lflows_processed,
+                                      l_ctx_out.objs_processed,
                                       &l_ctx_in, &l_ctx_out, &changed)) {
             return false;
         }
@@ -3241,7 +3248,7 @@  lflow_output_port_groups_handler(struct engine_node *node, void *data)
         if (!objdep_mgr_handle_change(l_ctx_out.lflow_deps_mgr,
                                       OBJDEP_TYPE_PORTGROUP, ref_name,
                                       lflow_handle_changed_ref,
-                                      l_ctx_out.lflows_processed,
+                                      l_ctx_out.objs_processed,
                                       &l_ctx_in, &l_ctx_out, &changed)) {
             return false;
         }
@@ -3275,7 +3282,17 @@  lflow_output_template_vars_handler(struct engine_node *node, void *data)
         if (!objdep_mgr_handle_change(l_ctx_out.lflow_deps_mgr,
                                       OBJDEP_TYPE_TEMPLATE,
                                       res_name, lflow_handle_changed_ref,
-                                      l_ctx_out.lflows_processed,
+                                      l_ctx_out.objs_processed,
+                                      &l_ctx_in, &l_ctx_out, &changed)) {
+            return false;
+        }
+        if (changed) {
+            engine_set_node_state(node, EN_UPDATED);
+        }
+        if (!objdep_mgr_handle_change(l_ctx_out.lb_deps_mgr,
+                                      OBJDEP_TYPE_TEMPLATE,
+                                      res_name, lb_handle_changed_ref,
+                                      l_ctx_out.objs_processed,
                                       &l_ctx_in, &l_ctx_out, &changed)) {
             return false;
         }
@@ -3287,7 +3304,17 @@  lflow_output_template_vars_handler(struct engine_node *node, void *data)
         if (!objdep_mgr_handle_change(l_ctx_out.lflow_deps_mgr,
                                       OBJDEP_TYPE_TEMPLATE,
                                       res_name, lflow_handle_changed_ref,
-                                      l_ctx_out.lflows_processed,
+                                      l_ctx_out.objs_processed,
+                                      &l_ctx_in, &l_ctx_out, &changed)) {
+            return false;
+        }
+        if (changed) {
+            engine_set_node_state(node, EN_UPDATED);
+        }
+        if (!objdep_mgr_handle_change(l_ctx_out.lb_deps_mgr,
+                                      OBJDEP_TYPE_TEMPLATE,
+                                      res_name, lb_handle_changed_ref,
+                                      l_ctx_out.objs_processed,
                                       &l_ctx_in, &l_ctx_out, &changed)) {
             return false;
         }
@@ -3299,7 +3326,17 @@  lflow_output_template_vars_handler(struct engine_node *node, void *data)
         if (!objdep_mgr_handle_change(l_ctx_out.lflow_deps_mgr,
                                       OBJDEP_TYPE_TEMPLATE,
                                       res_name, lflow_handle_changed_ref,
-                                      l_ctx_out.lflows_processed,
+                                      l_ctx_out.objs_processed,
+                                      &l_ctx_in, &l_ctx_out, &changed)) {
+            return false;
+        }
+        if (changed) {
+            engine_set_node_state(node, EN_UPDATED);
+        }
+        if (!objdep_mgr_handle_change(l_ctx_out.lb_deps_mgr,
+                                      OBJDEP_TYPE_TEMPLATE,
+                                      res_name, lb_handle_changed_ref,
+                                      l_ctx_out.objs_processed,
                                       &l_ctx_in, &l_ctx_out, &changed)) {
             return false;
         }
diff --git a/lib/lb.c b/lib/lb.c
index ab5de38a89..caeb9a8be7 100644
--- a/lib/lb.c
+++ b/lib/lb.c
@@ -19,6 +19,7 @@ 
 #include "lib/ovn-nb-idl.h"
 #include "lib/ovn-sb-idl.h"
 #include "lib/ovn-util.h"
+#include "ovn/lex.h"
 
 /* OpenvSwitch lib includes. */
 #include "openvswitch/vlog.h"
@@ -26,6 +27,16 @@ 
 
 VLOG_DEFINE_THIS_MODULE(lb);
 
+static const char *lb_neighbor_responder_mode_names[] = {
+    [LB_NEIGH_RESPOND_REACHABLE] = "reachable",
+    [LB_NEIGH_RESPOND_ALL] = "all",
+    [LB_NEIGH_RESPOND_NONE] = "none",
+};
+
+static struct nbrec_load_balancer_health_check *
+ovn_lb_get_health_check(const struct nbrec_load_balancer *nbrec_lb,
+                        const char *vip_port_str, bool template);
+
 struct ovn_lb_ip_set *
 ovn_lb_ip_set_create(void)
 {
@@ -71,94 +82,297 @@  ovn_lb_ip_set_clone(struct ovn_lb_ip_set *lb_ip_set)
     return clone;
 }
 
-static
-bool ovn_lb_vip_init(struct ovn_lb_vip *lb_vip, const char *lb_key,
-                     const char *lb_value)
+/* Format for backend ips: "IP1:port1,IP2:port2,...". */
+static char *
+ovn_lb_backends_init_explicit(struct ovn_lb_vip *lb_vip, const char *value,
+                              size_t *n_backends)
 {
-    int addr_family;
-
-    if (!ip_address_and_port_from_lb_key(lb_key, &lb_vip->vip_str,
-                                         &lb_vip->vip, &lb_vip->vip_port,
-                                         &addr_family)) {
-        return false;
-    }
-
-    /* Format for backend ips: "IP1:port1,IP2:port2,...". */
-    size_t n_backends = 0;
+    struct ds errors = DS_EMPTY_INITIALIZER;
     size_t n_allocated_backends = 0;
-    char *tokstr = xstrdup(lb_value);
+    char *tokstr = xstrdup(value);
     char *save_ptr = NULL;
+    *n_backends = 0;
+
     for (char *token = strtok_r(tokstr, ",", &save_ptr);
         token != NULL;
         token = strtok_r(NULL, ",", &save_ptr)) {
 
-        if (n_backends == n_allocated_backends) {
+        if (*n_backends == n_allocated_backends) {
             lb_vip->backends = x2nrealloc(lb_vip->backends,
                                           &n_allocated_backends,
                                           sizeof *lb_vip->backends);
         }
 
-        struct ovn_lb_backend *backend = &lb_vip->backends[n_backends];
+        struct ovn_lb_backend *backend = &lb_vip->backends[(*n_backends)];
         int backend_addr_family;
         if (!ip_address_and_port_from_lb_key(token, &backend->ip_str,
                                              &backend->ip, &backend->port,
                                              &backend_addr_family)) {
+            if (lb_vip->port_str) {
+                ds_put_format(&errors, "%s: should be an IP address and a "
+                                       "port number with : as a separator, ",
+                              token);
+            } else {
+                ds_put_format(&errors, "%s: should be an IP address, ", token);
+            }
             continue;
         }
 
-        if (addr_family != backend_addr_family) {
+        if (lb_vip->address_family != backend_addr_family) {
             free(backend->ip_str);
+            ds_put_format(&errors, "%s: IP address family is different from "
+                                   "VIP %s, ",
+                          token, lb_vip->vip_str);
             continue;
         }
 
-        n_backends++;
+        if (lb_vip->port_str) {
+            if (!backend->port) {
+                free(backend->ip_str);
+                ds_put_format(&errors, "%s: should be an IP address and "
+                                       "a port number with : as a separator, ",
+                              token);
+                continue;
+            }
+        } else {
+            if (backend->port) {
+                free(backend->ip_str);
+                ds_put_format(&errors, "%s: should be an IP address, ", token);
+                continue;
+            }
+        }
+
+        backend->port_str =
+            backend->port ? xasprintf("%"PRIu16, backend->port) : NULL;
+        (*n_backends)++;
     }
     free(tokstr);
-    lb_vip->n_backends = n_backends;
-    return true;
+
+    if (ds_last(&errors) != EOF) {
+        ds_chomp(&errors, ' ');
+        ds_chomp(&errors, ',');
+        ds_put_char(&errors, '.');
+        return ds_steal_cstr(&errors);
+    }
+    return NULL;
 }
 
 static
-void ovn_lb_vip_destroy(struct ovn_lb_vip *vip)
+char *ovn_lb_vip_init_explicit(struct ovn_lb_vip *lb_vip, const char *lb_key,
+                               const char *lb_value)
+{
+    if (!ip_address_and_port_from_lb_key(lb_key, &lb_vip->vip_str,
+                                         &lb_vip->vip, &lb_vip->vip_port,
+                                         &lb_vip->address_family)) {
+        return xasprintf("%s: should be an IP address (or an IP address "
+                         "and a port number with : as a separator).", lb_key);
+    }
+
+    lb_vip->port_str = lb_vip->vip_port
+                       ? xasprintf("%"PRIu16, lb_vip->vip_port)
+                       : NULL;
+
+    return ovn_lb_backends_init_explicit(lb_vip, lb_value,
+                                         &lb_vip->n_backends);
+}
+
+/* Parses backends of a templated LB VIP.
+ * For now only the following template forms are supported:
+ * A.
+ *   ^backendip_variable1[:^port_variable1|:port],
+ *   ^backendip_variable2[:^port_variable2|:port]
+ *
+ * B.
+ *   ^backends_variable1,^backends_variable2 is also a thing
+ *      where 'backends_variable1' may expand to IP1_1:PORT1_1 on chassis-1
+ *                                               IP1_2:PORT1_2 on chassis-2
+ *        and 'backends_variable2' may expand to IP2_1:PORT2_1 on chassis-1
+ *                                               IP2_2:PORT2_2 on chassis-2
+ */
+static char *
+ovn_lb_backends_init_template(struct ovn_lb_vip *lb_vip, const char *value_,
+                              size_t *n_backends)
+{
+    struct ds errors = DS_EMPTY_INITIALIZER;
+    char *value = xstrdup(value_);
+    char *save_ptr = NULL;
+    size_t n_allocated_backends = 0;
+    *n_backends = 0;
+
+    for (char *backend = strtok_r(value, ",", &save_ptr); backend;
+         backend = strtok_r(NULL, ",", &save_ptr)) {
+
+        char *atom = xstrdup(backend);
+        char *save_ptr2 = NULL;
+        bool success = false;
+        char *backend_ip = NULL;
+        char *backend_port = NULL;
+
+        for (char *subatom = strtok_r(atom, ":", &save_ptr2); subatom;
+             subatom = strtok_r(NULL, ":", &save_ptr2)) {
+            if (backend_ip && backend_port) {
+                success = false;
+                break;
+            }
+            success = true;
+            if (!backend_ip) {
+                backend_ip = xstrdup(subatom);
+            } else {
+                backend_port = xstrdup(subatom);
+            }
+        }
+
+        if (success) {
+            if (*n_backends == n_allocated_backends) {
+                lb_vip->backends = x2nrealloc(lb_vip->backends,
+                                              &n_allocated_backends,
+                                              sizeof *lb_vip->backends);
+            }
+
+            struct ovn_lb_backend *lb_backend =
+                &lb_vip->backends[(*n_backends)];
+            lb_backend->ip_str = backend_ip;
+            lb_backend->port_str = backend_port;
+            lb_backend->port = 0;
+            (*n_backends)++;
+        } else {
+            ds_put_format(&errors, "%s: should be a template of the form: "
+                          "'^backendip_variable1[:^port_variable1|:port]', ",
+                          atom);
+        }
+        free(atom);
+    }
+
+    free(value);
+    if (ds_last(&errors) != EOF) {
+        ds_chomp(&errors, ' ');
+        ds_chomp(&errors, ',');
+        ds_put_char(&errors, '.');
+        return ds_steal_cstr(&errors);
+    }
+    return NULL;
+}
+
+/* Parses a VIP of a templated LB.
+ * For now only the following template forms are supported:
+ *   ^vip_variable[:^port_variable|:port]
+ */
+static char *
+ovn_lb_vip_init_template(struct ovn_lb_vip *lb_vip, const char *lb_key_,
+                         const char *lb_value, int address_family)
+{
+    char *save_ptr = NULL;
+    char *lb_key = xstrdup(lb_key_);
+    bool success = false;
+
+    for (char *atom = strtok_r(lb_key, ":", &save_ptr); atom;
+         atom = strtok_r(NULL, ":", &save_ptr)) {
+        if (lb_vip->vip_str && lb_vip->port_str) {
+            success = false;
+            break;
+        }
+        success = true;
+        if (!lb_vip->vip_str) {
+            lb_vip->vip_str = xstrdup(atom);
+        } else {
+            lb_vip->port_str = xstrdup(atom);
+        }
+    }
+    free(lb_key);
+
+    if (!success) {
+        return xasprintf("%s: should be a template of the form: "
+                         "'^vip_variable[:^port_variable|:port]'.",
+                         lb_key_);
+    }
+
+    lb_vip->address_family = address_family;
+    return ovn_lb_backends_init_template(lb_vip, lb_value,
+                                         &lb_vip->n_backends);
+}
+
+/* Returns NULL on success, an error string on failure.  The caller is
+ * responsible for destroying 'lb_vip' in all cases.
+ */
+char *
+ovn_lb_vip_init(struct ovn_lb_vip *lb_vip, const char *lb_key,
+                const char *lb_value, bool template, int address_family)
+{
+    memset(lb_vip, 0, sizeof *lb_vip);
+
+    return !template
+           ?  ovn_lb_vip_init_explicit(lb_vip, lb_key, lb_value)
+           :  ovn_lb_vip_init_template(lb_vip, lb_key, lb_value,
+                                       address_family);
+}
+
+void
+ovn_lb_vip_destroy(struct ovn_lb_vip *vip)
 {
     free(vip->vip_str);
+    free(vip->port_str);
     for (size_t i = 0; i < vip->n_backends; i++) {
         free(vip->backends[i].ip_str);
+        free(vip->backends[i].port_str);
     }
     free(vip->backends);
 }
 
+void
+ovn_lb_vip_format(const struct ovn_lb_vip *vip, struct ds *s, bool template)
+{
+    bool needs_brackets = vip->address_family == AF_INET6 && vip->port_str
+                          && !template;
+    if (needs_brackets) {
+        ds_put_char(s, '[');
+    }
+    ds_put_cstr(s, vip->vip_str);
+    if (needs_brackets) {
+        ds_put_char(s, ']');
+    }
+    if (vip->port_str) {
+        ds_put_format(s, ":%s", vip->port_str);
+    }
+}
+
+void
+ovn_lb_vip_backends_format(const struct ovn_lb_vip *vip, struct ds *s,
+                           bool template)
+{
+    bool needs_brackets = vip->address_family == AF_INET6 && vip->port_str
+                          && !template;
+    for (size_t i = 0; i < vip->n_backends; i++) {
+        struct ovn_lb_backend *backend = &vip->backends[i];
+
+        if (needs_brackets) {
+            ds_put_char(s, '[');
+        }
+        ds_put_cstr(s, backend->ip_str);
+        if (needs_brackets) {
+            ds_put_char(s, ']');
+        }
+        if (backend->port_str) {
+            ds_put_format(s, ":%s", backend->port_str);
+        }
+        if (i != vip->n_backends - 1) {
+            ds_put_char(s, ',');
+        }
+    }
+}
+
 static
 void ovn_northd_lb_vip_init(struct ovn_northd_lb_vip *lb_vip_nb,
                             const struct ovn_lb_vip *lb_vip,
                             const struct nbrec_load_balancer *nbrec_lb,
-                            const char *vip_port_str, const char *backend_ips)
+                            const char *vip_port_str, const char *backend_ips,
+                            bool template)
 {
     lb_vip_nb->backend_ips = xstrdup(backend_ips);
     lb_vip_nb->n_backends = lb_vip->n_backends;
     lb_vip_nb->backends_nb = xcalloc(lb_vip_nb->n_backends,
                                      sizeof *lb_vip_nb->backends_nb);
-
-    struct nbrec_load_balancer_health_check *lb_health_check = NULL;
-    if (nbrec_lb->protocol && !strcmp(nbrec_lb->protocol, "sctp")) {
-        if (nbrec_lb->n_health_check > 0) {
-            static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 1);
-            VLOG_WARN_RL(&rl,
-                         "SCTP load balancers do not currently support "
-                         "health checks. Not creating health checks for "
-                         "load balancer " UUID_FMT,
-                         UUID_ARGS(&nbrec_lb->header_.uuid));
-        }
-    } else {
-        for (size_t j = 0; j < nbrec_lb->n_health_check; j++) {
-            if (!strcmp(nbrec_lb->health_check[j]->vip, vip_port_str)) {
-                lb_health_check = nbrec_lb->health_check[j];
-                break;
-            }
-        }
-    }
-
-    lb_vip_nb->lb_health_check = lb_health_check;
+    lb_vip_nb->lb_health_check =
+        ovn_lb_get_health_check(nbrec_lb, vip_port_str, template);
 }
 
 static
@@ -189,12 +403,112 @@  ovn_lb_get_hairpin_snat_ip(const struct uuid *lb_uuid,
     }
 }
 
+static bool
+ovn_lb_get_routable_mode(const struct nbrec_load_balancer *nbrec_lb,
+                         bool routable, bool template)
+{
+    if (template && routable) {
+        static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 1);
+        VLOG_WARN_RL(&rl, "Template load balancer "UUID_FMT" does not suport "
+                           "option 'add_route'.  Forcing it to disabled.",
+                     UUID_ARGS(&nbrec_lb->header_.uuid));
+        return false;
+    }
+    return routable;
+}
+
+static bool
+ovn_lb_neigh_mode_is_valid(enum lb_neighbor_responder_mode mode, bool template)
+{
+    if (!template) {
+        return true;
+    }
+
+    switch (mode) {
+    case LB_NEIGH_RESPOND_REACHABLE:
+        return false;
+    case LB_NEIGH_RESPOND_ALL:
+    case LB_NEIGH_RESPOND_NONE:
+        return true;
+    }
+    return false;
+}
+
+static enum lb_neighbor_responder_mode
+ovn_lb_get_neigh_mode(const struct nbrec_load_balancer *nbrec_lb,
+                      const char *mode, bool template)
+{
+    static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 1);
+    enum lb_neighbor_responder_mode default_mode =
+        template ? LB_NEIGH_RESPOND_NONE : LB_NEIGH_RESPOND_REACHABLE;
+
+    if (!mode) {
+        mode = lb_neighbor_responder_mode_names[default_mode];
+    }
+
+    for (size_t i = 0; i < ARRAY_SIZE(lb_neighbor_responder_mode_names); i++) {
+        if (!strcmp(mode, lb_neighbor_responder_mode_names[i])) {
+            if (ovn_lb_neigh_mode_is_valid(i, template)) {
+                return i;
+            }
+            break;
+        }
+    }
+
+    VLOG_WARN_RL(&rl, "Invalid neighbor responder mode %s for load balancer "
+                       UUID_FMT", forcing it to %s",
+                 mode, UUID_ARGS(&nbrec_lb->header_.uuid),
+                 lb_neighbor_responder_mode_names[default_mode]);
+    return default_mode;
+}
+
+static struct nbrec_load_balancer_health_check *
+ovn_lb_get_health_check(const struct nbrec_load_balancer *nbrec_lb,
+                        const char *vip_port_str, bool template)
+{
+    static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 1);
+
+    if (!nbrec_lb->n_health_check) {
+        return NULL;
+    }
+
+    if (nbrec_lb->protocol && !strcmp(nbrec_lb->protocol, "sctp")) {
+        VLOG_WARN_RL(&rl,
+                     "SCTP load balancers do not currently support "
+                     "health checks. Not creating health checks for "
+                     "load balancer " UUID_FMT,
+                     UUID_ARGS(&nbrec_lb->header_.uuid));
+        return NULL;
+    }
+
+    if (template) {
+        VLOG_WARN_RL(&rl,
+                     "Template load balancers do not currently support "
+                     "health checks. Not creating health checks for "
+                     "load balancer " UUID_FMT,
+                     UUID_ARGS(&nbrec_lb->header_.uuid));
+        return NULL;
+    }
+
+    for (size_t i = 0; i < nbrec_lb->n_health_check; i++) {
+        if (!strcmp(nbrec_lb->health_check[i]->vip, vip_port_str)) {
+            return nbrec_lb->health_check[i];
+        }
+    }
+    return NULL;
+}
+
 struct ovn_northd_lb *
 ovn_northd_lb_create(const struct nbrec_load_balancer *nbrec_lb)
 {
     bool is_udp = nullable_string_is_equal(nbrec_lb->protocol, "udp");
     bool is_sctp = nullable_string_is_equal(nbrec_lb->protocol, "sctp");
     struct ovn_northd_lb *lb = xzalloc(sizeof *lb);
+    int address_family = !strcmp(smap_get_def(&nbrec_lb->options,
+                                              "address-family", "ipv4"),
+                                 "ipv4")
+                         ? AF_INET
+                         : AF_INET6;
 
     lb->nlb = nbrec_lb;
     lb->proto = is_udp ? "udp" : is_sctp ? "sctp" : "tcp";
@@ -202,12 +516,16 @@  ovn_northd_lb_create(const struct nbrec_load_balancer *nbrec_lb)
     lb->vips = xcalloc(lb->n_vips, sizeof *lb->vips);
     lb->vips_nb = xcalloc(lb->n_vips, sizeof *lb->vips_nb);
     lb->controller_event = smap_get_bool(&nbrec_lb->options, "event", false);
-    lb->routable = smap_get_bool(&nbrec_lb->options, "add_route", false);
+
+    bool routable = smap_get_bool(&nbrec_lb->options, "add_route", false);
+    lb->routable = ovn_lb_get_routable_mode(nbrec_lb, routable, lb->template);
+
     lb->skip_snat = smap_get_bool(&nbrec_lb->options, "skip_snat", false);
-    const char *mode =
-        smap_get_def(&nbrec_lb->options, "neighbor_responder", "reachable");
-    lb->neigh_mode = strcmp(mode, "all") ? LB_NEIGH_RESPOND_REACHABLE
-                                         : LB_NEIGH_RESPOND_ALL;
+    lb->template = smap_get_bool(&nbrec_lb->options, "template", false);
+
+    const char *mode = smap_get(&nbrec_lb->options, "neighbor_responder");
+    lb->neigh_mode = ovn_lb_get_neigh_mode(nbrec_lb, mode, lb->template);
+
     sset_init(&lb->ips_v4);
     sset_init(&lb->ips_v6);
     struct smap_node *node;
@@ -217,13 +535,19 @@  ovn_northd_lb_create(const struct nbrec_load_balancer *nbrec_lb)
         struct ovn_lb_vip *lb_vip = &lb->vips[n_vips];
         struct ovn_northd_lb_vip *lb_vip_nb = &lb->vips_nb[n_vips];
 
-        lb_vip->empty_backend_rej = smap_get_bool(&nbrec_lb->options,
-                                                  "reject", false);
-        if (!ovn_lb_vip_init(lb_vip, node->key, node->value)) {
+        char *error = ovn_lb_vip_init(lb_vip, node->key, node->value,
+                                      lb->template, address_family);
+        if (error) {
+            static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 1);
+            VLOG_WARN_RL(&rl, "Failed to initialize LB VIP: %s", error);
+            ovn_lb_vip_destroy(lb_vip);
+            free(error);
             continue;
         }
+        lb_vip->empty_backend_rej = smap_get_bool(&nbrec_lb->options,
+                                                  "reject", false);
         ovn_northd_lb_vip_init(lb_vip_nb, lb_vip, nbrec_lb,
-                               node->key, node->value);
+                               node->key, node->value, lb->template);
         if (IN6_IS_ADDR_V4MAPPED(&lb_vip->vip)) {
             sset_add(&lb->ips_v4, lb_vip->vip_str);
         } else {
@@ -371,9 +695,12 @@  ovn_lb_group_find(const struct hmap *lb_groups, const struct uuid *uuid)
 }
 
 struct ovn_controller_lb *
-ovn_controller_lb_create(const struct sbrec_load_balancer *sbrec_lb)
+ovn_controller_lb_create(const struct sbrec_load_balancer *sbrec_lb,
+                         const struct smap *template_vars,
+                         struct sset *template_vars_ref)
 {
     struct ovn_controller_lb *lb = xzalloc(sizeof *lb);
+    bool template = smap_get_bool(&sbrec_lb->options, "template", false);
 
     lb->slb = sbrec_lb;
     lb->n_vips = smap_count(&sbrec_lb->vips);
@@ -385,10 +712,28 @@  ovn_controller_lb_create(const struct sbrec_load_balancer *sbrec_lb)
     SMAP_FOR_EACH (node, &sbrec_lb->vips) {
         struct ovn_lb_vip *lb_vip = &lb->vips[n_vips];
 
-        if (!ovn_lb_vip_init(lb_vip, node->key, node->value)) {
-            continue;
+        char *key_expanded_s = NULL;
+        const char *key_s = template
+                            ? lexer_parse_template_string(node->key,
+                                                          template_vars,
+                                                          template_vars_ref,
+                                                          &key_expanded_s)
+                            : node->key;
+        char *value_expanded_s = NULL;
+        const char *value_s = template
+                              ? lexer_parse_template_string(node->value,
+                                                            template_vars,
+                                                            template_vars_ref,
+                                                            &value_expanded_s)
+                              : node->value;
+        char *error = ovn_lb_vip_init_explicit(lb_vip, key_s, value_s);
+        if (error) {
+            free(error);
+        } else {
+            n_vips++;
         }
-        n_vips++;
+        free(key_expanded_s);
+        free(value_expanded_s);
     }
 
     /* It's possible that parsing VIPs fails.  Update the lb->n_vips to the
diff --git a/lib/lb.h b/lib/lb.h
index c1aadd6dd5..42bc5afecb 100644
--- a/lib/lb.h
+++ b/lib/lb.h
@@ -35,6 +35,7 @@  struct uuid;
 enum lb_neighbor_responder_mode {
     LB_NEIGH_RESPOND_REACHABLE,
     LB_NEIGH_RESPOND_ALL,
+    LB_NEIGH_RESPOND_NONE,
 };
 
 /* The "routable" ssets are subsets of the load balancer IPs for which IP
@@ -67,6 +68,7 @@  struct ovn_northd_lb {
     bool controller_event;
     bool routable;
     bool skip_snat;
+    bool template;
 
     struct sset ips_v4;
     struct sset ips_v6;
@@ -81,19 +83,31 @@  struct ovn_northd_lb {
 };
 
 struct ovn_lb_vip {
-    struct in6_addr vip;
-    char *vip_str;
-    uint16_t vip_port;
-
+    struct in6_addr vip; /* Only used in ovn-controller. */
+    char *vip_str;       /* Actual VIP string representation (without port).
+                          * To be used in ovn-northd.
+                          */
+    uint16_t vip_port;   /* Only used in ovn-controller. */
+    char *port_str;      /* Actual port string representation.  To be used
+                          * in ovn-controller.
+                          */
     struct ovn_lb_backend *backends;
     size_t n_backends;
     bool empty_backend_rej;
+    int address_family;
 };
 
 struct ovn_lb_backend {
-    struct in6_addr ip;
-    char *ip_str;
-    uint16_t port;
+    struct in6_addr ip;  /* Only used in ovn-controller. */
+    char *ip_str;        /* Actual IP string representation. To be used in
+                          * ovn-northd.
+                          */
+    uint16_t port;       /* Mostly used in ovn-controller but also for
+                          * healthcheck in ovn-northd.
+                          */
+    char *port_str;      /* Actual port string representation. To be used
+                          * in ovn-northd.
+                          */
 };
 
 /* ovn-northd specific backend information. */
@@ -173,7 +187,17 @@  struct ovn_controller_lb {
 };
 
 struct ovn_controller_lb *ovn_controller_lb_create(
-    const struct sbrec_load_balancer *);
+    const struct sbrec_load_balancer *,
+    const struct smap *template_vars,
+    struct sset *template_vars_ref);
 void ovn_controller_lb_destroy(struct ovn_controller_lb *);
 
+char *ovn_lb_vip_init(struct ovn_lb_vip *lb_vip, const char *lb_key,
+                      const char *lb_value, bool template, int address_family);
+void ovn_lb_vip_destroy(struct ovn_lb_vip *vip);
+void ovn_lb_vip_format(const struct ovn_lb_vip *vip, struct ds *s,
+                       bool template);
+void ovn_lb_vip_backends_format(const struct ovn_lb_vip *vip, struct ds *s,
+                                bool template);
+
 #endif /* OVN_LIB_LB_H 1 */
diff --git a/lib/ovn-util.c b/lib/ovn-util.c
index 5dca727146..91b572feb3 100644
--- a/lib/ovn-util.c
+++ b/lib/ovn-util.c
@@ -793,9 +793,6 @@  ip_address_and_port_from_lb_key(const char *key, char **ip_address,
 {
     struct sockaddr_storage ss;
     if (!inet_parse_active(key, 0, &ss, false, NULL)) {
-        static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 1);
-        VLOG_WARN_RL(&rl, "bad ip address or port for load balancer key %s",
-                     key);
         *ip_address = NULL;
         memset(ip, 0, sizeof(*ip));
         *port = 0;
diff --git a/northd/northd.c b/northd/northd.c
index 170b4f95c8..e12b91a3a6 100644
--- a/northd/northd.c
+++ b/northd/northd.c
@@ -3720,6 +3720,10 @@  static void
 ovn_lb_svc_create(struct ovsdb_idl_txn *ovnsb_txn, struct ovn_northd_lb *lb,
                   struct hmap *monitor_map, struct hmap *ports)
 {
+    if (lb->template) {
+        return;
+    }
+
     for (size_t i = 0; i < lb->n_vips; i++) {
         struct ovn_lb_vip *lb_vip = &lb->vips[i];
         struct ovn_northd_lb_vip *lb_vip_nb = &lb->vips_nb[i];
@@ -4036,12 +4040,19 @@  static void
 build_lrouter_lb_reachable_ips(struct ovn_datapath *od,
                                const struct ovn_northd_lb *lb)
 {
+    /* If configured to not reply to any neighbor requests for all VIPs
+     * return early.
+     */
+    if (lb->neigh_mode == LB_NEIGH_RESPOND_NONE) {
+        return;
+    }
+
     /* If configured to reply to neighbor requests for all VIPs force them
      * all to be considered "reachable".
      */
     if (lb->neigh_mode == LB_NEIGH_RESPOND_ALL) {
         for (size_t i = 0; i < lb->n_vips; i++) {
-            if (IN6_IS_ADDR_V4MAPPED(&lb->vips[i].vip)) {
+            if (lb->vips[i].address_family == AF_INET) {
                 sset_add(&od->lb_ips->ips_v4_reachable, lb->vips[i].vip_str);
             } else {
                 sset_add(&od->lb_ips->ips_v6_reachable, lb->vips[i].vip_str);
@@ -4053,8 +4064,9 @@  build_lrouter_lb_reachable_ips(struct ovn_datapath *od,
     /* Otherwise, a VIP is reachable if there's at least one router
      * subnet that includes it.
      */
+    ovs_assert(lb->neigh_mode == LB_NEIGH_RESPOND_REACHABLE);
     for (size_t i = 0; i < lb->n_vips; i++) {
-        if (IN6_IS_ADDR_V4MAPPED(&lb->vips[i].vip)) {
+        if (lb->vips[i].address_family == AF_INET) {
             ovs_be32 vip_ip4 = in6_addr_get_mapped_ipv4(&lb->vips[i].vip);
             struct ovn_port *op;
 
@@ -5814,16 +5826,16 @@  build_empty_lb_event_flow(struct ovn_lb_vip *lb_vip,
     ds_clear(action);
     ds_clear(match);
 
-    bool ipv4 = IN6_IS_ADDR_V4MAPPED(&lb_vip->vip);
+    bool ipv4 = lb_vip->address_family == AF_INET;
 
     ds_put_format(match, "ip%s.dst == %s && %s",
                   ipv4 ? "4": "6", lb_vip->vip_str, lb->proto);
 
     char *vip = lb_vip->vip_str;
-    if (lb_vip->vip_port) {
-        ds_put_format(match, " && %s.dst == %u", lb->proto, lb_vip->vip_port);
-        vip = xasprintf("%s%s%s:%u", ipv4 ? "" : "[", lb_vip->vip_str,
-                        ipv4 ? "" : "]", lb_vip->vip_port);
+    if (lb_vip->port_str) {
+        ds_put_format(match, " && %s.dst == %s", lb->proto, lb_vip->port_str);
+        vip = xasprintf("%s%s%s:%s", ipv4 ? "" : "[", lb_vip->vip_str,
+                        ipv4 ? "" : "]", lb_vip->port_str);
     }
 
     ds_put_format(action,
@@ -5834,7 +5846,7 @@  build_empty_lb_event_flow(struct ovn_lb_vip *lb_vip,
                   event_to_string(OVN_EVENT_EMPTY_LB_BACKENDS),
                   vip, lb->proto,
                   UUID_ARGS(&lb->nlb->header_.uuid));
-    if (lb_vip->vip_port) {
+    if (lb_vip->port_str) {
         free(vip);
     }
     return true;
@@ -6890,7 +6902,7 @@  build_lb_rules_pre_stateful(struct hmap *lflows, struct ovn_northd_lb *lb,
         /* Store the original destination IP to be used when generating
          * hairpin flows.
          */
-        if (IN6_IS_ADDR_V4MAPPED(&lb_vip->vip)) {
+        if (lb->vips[i].address_family == AF_INET) {
             ip_match = "ip4";
             ds_put_format(action, REG_ORIG_DIP_IPV4 " = %s; ",
                           lb_vip->vip_str);
@@ -6901,7 +6913,7 @@  build_lb_rules_pre_stateful(struct hmap *lflows, struct ovn_northd_lb *lb,
         }
 
         const char *proto = NULL;
-        if (lb_vip->vip_port) {
+        if (lb_vip->port_str) {
             proto = "tcp";
             if (lb->nlb->protocol) {
                 if (!strcmp(lb->nlb->protocol, "udp")) {
@@ -6914,14 +6926,14 @@  build_lb_rules_pre_stateful(struct hmap *lflows, struct ovn_northd_lb *lb,
             /* Store the original destination port to be used when generating
              * hairpin flows.
              */
-            ds_put_format(action, REG_ORIG_TP_DPORT " = %"PRIu16"; ",
-                          lb_vip->vip_port);
+            ds_put_format(action, REG_ORIG_TP_DPORT " = %s; ",
+                          lb_vip->port_str);
         }
         ds_put_format(action, "%s;", ct_lb_mark ? "ct_lb_mark" : "ct_lb");
 
         ds_put_format(match, "%s.dst == %s", ip_match, lb_vip->vip_str);
-        if (lb_vip->vip_port) {
-            ds_put_format(match, " && %s.dst == %d", proto, lb_vip->vip_port);
+        if (lb_vip->port_str) {
+            ds_put_format(match, " && %s.dst == %s", proto, lb_vip->port_str);
         }
 
         struct ovn_lflow *lflow_ref = NULL;
@@ -6953,24 +6965,12 @@  build_lb_rules(struct hmap *lflows, struct ovn_northd_lb *lb, bool ct_lb_mark,
         struct ovn_lb_vip *lb_vip = &lb->vips[i];
         struct ovn_northd_lb_vip *lb_vip_nb = &lb->vips_nb[i];
         const char *ip_match = NULL;
-        if (IN6_IS_ADDR_V4MAPPED(&lb_vip->vip)) {
+        if (lb_vip->address_family == AF_INET) {
             ip_match = "ip4";
         } else {
             ip_match = "ip6";
         }
 
-        const char *proto = NULL;
-        if (lb_vip->vip_port) {
-            proto = "tcp";
-            if (lb->nlb->protocol) {
-                if (!strcmp(lb->nlb->protocol, "udp")) {
-                    proto = "udp";
-                } else if (!strcmp(lb->nlb->protocol, "sctp")) {
-                    proto = "sctp";
-                }
-            }
-        }
-
         ds_clear(action);
         ds_clear(match);
 
@@ -6988,8 +6988,9 @@  build_lb_rules(struct hmap *lflows, struct ovn_northd_lb *lb, bool ct_lb_mark,
         ds_put_format(match, "ct.new && %s.dst == %s", ip_match,
                       lb_vip->vip_str);
         int priority = 110;
-        if (lb_vip->vip_port) {
-            ds_put_format(match, " && %s.dst == %d", proto, lb_vip->vip_port);
+        if (lb_vip->port_str) {
+            ds_put_format(match, " && %s.dst == %s", lb->proto,
+                          lb_vip->port_str);
             priority = 120;
         }
 
@@ -9989,7 +9990,7 @@  build_lrouter_nat_flows_for_lb(struct ovn_lb_vip *lb_vip,
      * of "ct_lb_mark($targets);". The other flow is for ct.est with
      * an action of "next;".
      */
-    if (IN6_IS_ADDR_V4MAPPED(&lb_vip->vip)) {
+    if (lb_vip->address_family == AF_INET) {
         ds_put_format(match, "ip4 && "REG_NEXT_HOP_IPV4" == %s",
                       lb_vip->vip_str);
     } else {
@@ -10005,14 +10006,14 @@  build_lrouter_nat_flows_for_lb(struct ovn_lb_vip *lb_vip,
     }
 
     int prio = 110;
-    if (lb_vip->vip_port) {
+    if (lb_vip->port_str) {
         prio = 120;
         new_match = xasprintf("ct.new && %s && %s && "
-                              REG_ORIG_TP_DPORT_ROUTER" == %d",
-                              ds_cstr(match), lb->proto, lb_vip->vip_port);
+                              REG_ORIG_TP_DPORT_ROUTER" == %s",
+                              ds_cstr(match), lb->proto, lb_vip->port_str);
         est_match = xasprintf("ct.est && %s && %s && "
-                              REG_ORIG_TP_DPORT_ROUTER" == %d && %s == 1",
-                              ds_cstr(match), lb->proto, lb_vip->vip_port,
+                              REG_ORIG_TP_DPORT_ROUTER" == %s && %s == 1",
+                              ds_cstr(match), lb->proto, lb_vip->port_str,
                               ct_natted);
     } else {
         new_match = xasprintf("ct.new && %s", ds_cstr(match));
@@ -10021,7 +10022,7 @@  build_lrouter_nat_flows_for_lb(struct ovn_lb_vip *lb_vip,
     }
 
     const char *ip_match = NULL;
-    if (IN6_IS_ADDR_V4MAPPED(&lb_vip->vip)) {
+    if (lb_vip->address_family == AF_INET) {
         ip_match = "ip4";
     } else {
         ip_match = "ip6";
@@ -10039,9 +10040,9 @@  build_lrouter_nat_flows_for_lb(struct ovn_lb_vip *lb_vip,
         ds_put_format(&undnat_match, "(%s.src == %s", ip_match,
                       backend->ip_str);
 
-        if (backend->port) {
-            ds_put_format(&undnat_match, " && %s.src == %d) || ",
-                          lb->proto, backend->port);
+        if (backend->port_str) {
+            ds_put_format(&undnat_match, " && %s.src == %s) || ",
+                          lb->proto, backend->port_str);
         } else {
             ds_put_cstr(&undnat_match, ") || ");
         }
@@ -10054,9 +10055,9 @@  build_lrouter_nat_flows_for_lb(struct ovn_lb_vip *lb_vip,
     struct ds unsnat_match = DS_EMPTY_INITIALIZER;
     ds_put_format(&unsnat_match, "%s && %s.dst == %s && %s",
                   ip_match, ip_match, lb_vip->vip_str, lb->proto);
-    if (lb_vip->vip_port) {
-        ds_put_format(&unsnat_match, " && %s.dst == %d", lb->proto,
-                      lb_vip->vip_port);
+    if (lb_vip->port_str) {
+        ds_put_format(&unsnat_match, " && %s.dst == %s", lb->proto,
+                      lb_vip->port_str);
     }
 
     struct ovn_datapath **gw_router_skip_snat =
@@ -10296,7 +10297,7 @@  build_lrouter_defrag_flows_for_lb(struct ovn_northd_lb *lb,
         ds_clear(&defrag_actions);
         ds_clear(match);
 
-        if (IN6_IS_ADDR_V4MAPPED(&lb_vip->vip)) {
+        if (lb_vip->address_family == AF_INET) {
             ds_put_format(match, "ip && ip4.dst == %s", lb_vip->vip_str);
             ds_put_format(&defrag_actions, REG_NEXT_HOP_IPV4" = %s; ",
                           lb_vip->vip_str);
@@ -10306,7 +10307,7 @@  build_lrouter_defrag_flows_for_lb(struct ovn_northd_lb *lb,
                           lb_vip->vip_str);
         }
 
-        if (lb_vip->vip_port) {
+        if (lb_vip->port_str) {
             ds_put_format(match, " && %s", lb->proto);
             prio = 110;
 
diff --git a/ovn-nb.xml b/ovn-nb.xml
index 45b75e66df..af3ac261bc 100644
--- a/ovn-nb.xml
+++ b/ovn-nb.xml
@@ -1905,8 +1905,57 @@ 
         is applied reply to ARP/neighbor discovery requests for all VIPs
         of the load balancer.  If set to <code>reachable</code>, then routers
         on which the load balancer is applied reply to ARP/neighbor discovery
-        requests only for VIPs that are part of a router's subnet.  The default
-        value of this option, if not specified, is <code>reachable</code>.
+        requests only for VIPs that are part of a router's subnet.  If set to
+        <code>none</code>, then routers on which the load balancer is applied
+        never reply to ARP/neighbor discovery requests for any of the load
+        balancer VIPs. Load balancers with <code>options:template=true</code>
+        do not support <code>reachable</code> as a valid mode.  The default
+        value of this option, if not specified, is <code>reachable</code> for
+        regular load balancers and <code>none</code> for template load
+        balancers.
+      </column>
+
+      <column name="options" key="template">
+        <p>
+          Option to be set to <code>true</code>, if the load balancer is a
+          template.  In this the load balancer VIPs and/or backends may be
+          using <ref table="Chassis_Template_Var"/> in their definition.
+        </p>
+
+        <p>
+          Load balancer template VIP supported formats are:
+        </p>
+        <pre>
+^VIP_VAR[:^PORT_VAR|:port]
+        </pre>
+
+        <p>
+          where <code>VIP_VAR</code> and <code>PORT_VAR</code> are names of
+        <ref table="Chassis_Template_Var"/> records.
+        </p>
+
+        <p>
+          Load balancer template backend supported formats are:
+        </p>
+        <pre>
+^BACKEND_VAR1[:^PORT_VAR1|:port],^BACKEND_VAR2[:^PORT_VAR2|:port]
+
+or
+
+^BACKENDS_VAR1,^BACKENDS_VAR2
+        </pre>
+        <p>
+          where <code>BACKEND_VAR1</code>, <code>PORT_VAR1</code>,
+          <code>BACKEND_VAR2</code>, <code>PORT_VAR2</code>,
+          <code>BACKENDS_VAR1</code> and <code>BACKENDS_VAR2</code> are names
+          of <ref table="Chassis_Template_Var"/> records.
+        </p>
+      </column>
+
+      <column name="options" key="address-family">
+        Address family used by the load balancer.  Supported values are
+        <code>ipv4</code> and <code>ipv6</code>.  This value is used and is
+        mandatory for load balancer with <code>options:template=true</code>.
       </column>
     </group>
   </table>
diff --git a/tests/ovn-nbctl.at b/tests/ovn-nbctl.at
index 4d480e3573..9da7c26b31 100644
--- a/tests/ovn-nbctl.at
+++ b/tests/ovn-nbctl.at
@@ -857,23 +857,19 @@  AT_CHECK([ovn-nbctl -vsocket_util:off lb-add lb0 30.0.0.10 192.168.10.10:a80], [
 [ovn-nbctl: 192.168.10.10:a80: should be an IP address.
 ])
 
-AT_CHECK([ovn-nbctl -vsocket_util:off lb-add lb0 30.0.0.10 192.168.10.10:], [1], [],
-[ovn-nbctl: 192.168.10.10:: should be an IP address.
-])
-
 AT_CHECK([ovn-nbctl -vsocket_util:off lb-add lb0 30.0.0.10 192.168.10.1a], [1], [],
 [ovn-nbctl: 192.168.10.1a: should be an IP address.
 ])
 
 AT_CHECK([ovn-nbctl lb-add lb0 30.0.0.10: 192.168.10.10:80,192.168.10.20:80 tcp], [1], [],
-[ovn-nbctl: Protocol is unnecessary when no port of vip is given.
+[ovn-nbctl: 192.168.10.10:80: should be an IP address, 192.168.10.20:80: should be an IP address.
 ])
 
 AT_CHECK([ovn-nbctl lb-add lb0 30.0.0.10 192.168.10.10 tcp], [1], [],
 [ovn-nbctl: Protocol is unnecessary when no port of vip is given.
 ])
 
-AT_CHECK([ovn-nbctl lb-add lb0 30.0.0.10 192.168.10.10:900 tcp], [1], [],
+AT_CHECK([ovn-nbctl lb-add lb0 30.0.0.10 192.168.10.10 tcp], [1], [],
 [ovn-nbctl: Protocol is unnecessary when no port of vip is given.
 ])
 
@@ -1111,7 +1107,7 @@  AT_CHECK([ovn-nbctl -vsocket_util:off lb-add lb0 ae0f::10fff [[fd0f::10]]:80,fd0
 
 
 AT_CHECK([ovn-nbctl -vsocket_util:off lb-add lb0 ae0f::10 [[fd0f::10]]:80,[[fd0f::20]]:80], [1], [],
-[ovn-nbctl: [[fd0f::10]]:80: should be an IP address.
+[ovn-nbctl: [[fd0f::10]]:80: should be an IP address, [[fd0f::20]]:80: should be an IP address.
 ])
 
 
@@ -1125,18 +1121,13 @@  AT_CHECK([ovn-nbctl -vsocket_util:off lb-add lb0 ae0f::10 [[fd0f::10]]:a80], [1]
 ])
 
 
-AT_CHECK([ovn-nbctl -vsocket_util:off lb-add lb0 ae0f::10 [[fd0f::10]]:], [1], [],
-[ovn-nbctl: [[fd0f::10]]:: should be an IP address.
-])
-
-
 AT_CHECK([ovn-nbctl -vsocket_util:off lb-add lb0 ae0f::10 fd0f::1001a], [1], [],
 [ovn-nbctl: fd0f::1001a: should be an IP address.
 ])
 
 
 AT_CHECK([ovn-nbctl -vsocket_util:off lb-add lb0 [[ae0f::10]]: [[fd0f::10]]:80,[[fd0f::20]]:80 tcp], [1], [],
-[ovn-nbctl: Protocol is unnecessary when no port of vip is given.
+[ovn-nbctl: [[fd0f::10]]:80: should be an IP address, [[fd0f::20]]:80: should be an IP address.
 ])
 
 
@@ -1146,7 +1137,7 @@  AT_CHECK([ovn-nbctl lb-add lb0 ae0f::10 fd0f::10 tcp], [1], [],
 
 
 AT_CHECK([ovn-nbctl lb-add lb0 ae0f::10 [[fd0f::10]]:900 tcp], [1], [],
-[ovn-nbctl: Protocol is unnecessary when no port of vip is given.
+[ovn-nbctl: [[fd0f::10]]:900: should be an IP address.
 ])
 
 AT_CHECK([ovn-nbctl lb-add lb0 ae0f::10 192.168.10.10], [1], [],
@@ -1158,7 +1149,7 @@  AT_CHECK([ovn-nbctl lb-add lb0 ae0f::10 192.168.10.10], [1], [],
 ])
 
 AT_CHECK([ovn-nbctl lb-add lb0 [[ae0f::10]]:80 192.168.10.10:80], [1], [],
-[ovn-nbctl: 192.168.10.10:80: IP address family is different from VIP [[ae0f::10]]:80.
+[ovn-nbctl: 192.168.10.10:80: IP address family is different from VIP ae0f::10.
 ])
 
 AT_CHECK([ovn-nbctl lb-add lb0 30.0.0.10 ae0f::10], [1], [],
@@ -1166,7 +1157,7 @@  AT_CHECK([ovn-nbctl lb-add lb0 30.0.0.10 ae0f::10], [1], [],
 ])
 
 AT_CHECK([ovn-nbctl lb-add lb0 30.0.0.10:80 [[ae0f::10]]:80], [1], [],
-[ovn-nbctl: [[ae0f::10]]:80: IP address family is different from VIP 30.0.0.10:80.
+[ovn-nbctl: [[ae0f::10]]:80: IP address family is different from VIP 30.0.0.10.
 ])
 
 AT_CHECK([ovn-nbctl lb-add lb0 ae0f::10 fd0f::10])
diff --git a/tests/ovn-northd.at b/tests/ovn-northd.at
index c7112b805d..d088961819 100644
--- a/tests/ovn-northd.at
+++ b/tests/ovn-northd.at
@@ -1828,6 +1828,11 @@  ovn-nbctl set Load_Balancer lb8 options:neighbor_responder=all
 ovn-nbctl lb-add lb9 "[[4444::4444]]:8080" "[[10::10]]:8080" udp
 ovn-nbctl set Load_Balancer lb9 options:neighbor_responder=all
 
+ovn-nbctl lb-add lb10 "55.55.55.55:8080" "10.0.0.8:8080" udp
+ovn-nbctl set Load_Balancer lb10 options:neighbor_responder=none
+ovn-nbctl lb-add lb11 "[[5555::5555]]:8080" "[[10::10]]:8080" udp
+ovn-nbctl set Load_Balancer lb11 options:neighbor_responder=none
+
 ovn-nbctl lr-lb-add lr lb1
 ovn-nbctl lr-lb-add lr lb2
 ovn-nbctl lr-lb-add lr lb3
@@ -1837,6 +1842,8 @@  ovn-nbctl lr-lb-add lr lb6
 ovn-nbctl lr-lb-add lr lb7
 ovn-nbctl lr-lb-add lr lb8
 ovn-nbctl lr-lb-add lr lb9
+ovn-nbctl lr-lb-add lr lb10
+ovn-nbctl lr-lb-add lr lb11
 
 ovn-nbctl --wait=sb sync
 lr_key=$(fetch_column sb:datapath_binding tunnel_key external_ids:name=lr)
diff --git a/tests/ovn.at b/tests/ovn.at
index 2a59235c59..45241d7e20 100644
--- a/tests/ovn.at
+++ b/tests/ovn.at
@@ -33053,3 +33053,134 @@  AT_CHECK([ovs-ofctl dump-flows br-int | grep '42\.42\.42\.42'], [1], [])
 OVN_CLEANUP([hv1])
 AT_CLEANUP
 ])
+
+OVN_FOR_EACH_NORTHD([
+AT_SETUP([Load balancers with Chassis_Template_Var references])
+AT_KEYWORDS([templates])
+ovn_start
+net_add n1
+
+sim_add hv1
+as hv1
+ovs-vsctl add-br br-phys
+ovn_attach n1 br-phys 192.168.0.1
+
+check ovn-nbctl ls-add sw
+
+dnl Use --wait=sb to ensure lsp1 getting a tunnel_key before lsp2.
+check ovn-nbctl --wait=sb lsp-add sw lsp1
+check ovn-nbctl --wait=sb lsp-add sw lsp2
+
+AT_CHECK([ovn-nbctl create Chassis_Template_Var chassis=hv1], [0], [ignore])
+
+dnl Create a few LBs that use "uninstantiated" templates.
+check ovn-nbctl --template lb-add lb-test1 "^VIP1:^VPORT1" "^BACKENDS1" tcp
+check ovn-nbctl --template lb-add lb-test2 "^VIP2:^VPORT2" "^BACKENDS21,^BACKENDS22" tcp
+check ovn-nbctl --template lb-add lb-test3 "^VIP3:^VPORT3" "^BACKENDS31:^BPORT1,^BACKENDS32:^BPORT2" tcp
+check ovn-nbctl ls-lb-add sw lb-test1
+check ovn-nbctl ls-lb-add sw lb-test2
+check ovn-nbctl ls-lb-add sw lb-test3
+
+check ovs-vsctl add-port br-int p1 -- set interface p1 external_ids:iface-id=lsp1
+check ovs-vsctl add-port br-int p2 -- set interface p2 external_ids:iface-id=lsp2
+
+wait_for_ports_up
+ovn-nbctl --wait=hv sync
+
+dnl Ensure the LBs are not translated to OpenFlow.
+as hv1
+AT_CHECK([ovs-ofctl dump-groups br-int | grep 'nat'], [1], [])
+
+dnl Create Chassis_Template_Var mappings.
+check ovn-nbctl --wait=hv set Chassis_Template_Var hv1 \
+    variables:VIP1='43.43.43.1' variables:VPORT1='4301' \
+    variables:BACKENDS1='85.85.85.1:8501' \
+    variables:VIP2='43.43.43.2' variables:VPORT2='4302' \
+    variables:BACKENDS21='85.85.85.21:8502' \
+    variables:BACKENDS22='85.85.85.22:8502' \
+    variables:VIP3='43.43.43.3' variables:VPORT3='4303' \
+    variables:BACKENDS31='85.85.85.31' \
+    variables:BACKENDS32='85.85.85.32' \
+    variables:BPORT1='8503' variables:BPORT2='8503'
+
+dnl Ensure the LBs are translated to OpenFlow.
+as hv1
+AT_CHECK([ovs-ofctl dump-groups br-int | grep 'nat(dst=85.85.85.1:8501)' -c], [0], [dnl
+1
+])
+AT_CHECK([ovs-ofctl dump-groups br-int | grep 'nat(dst=85.85.85.21:8502)' -c], [0], [dnl
+1
+])
+AT_CHECK([ovs-ofctl dump-groups br-int | grep 'nat(dst=85.85.85.22:8502)' -c], [0], [dnl
+1
+])
+AT_CHECK([ovs-ofctl dump-groups br-int | grep 'nat(dst=85.85.85.31:8503)' -c], [0], [dnl
+1
+])
+AT_CHECK([ovs-ofctl dump-groups br-int | grep 'nat(dst=85.85.85.32:8503)' -c], [0], [dnl
+1
+])
+
+dnl Ensure hairpin flows are correct.
+as hv1
+AT_CHECK([ovs-ofctl dump-flows br-int | grep table=68 | ofctl_strip_all], [0], [dnl
+ table=68, priority=100,ct_mark=0x2/0x2,tcp,reg1=0x2b2b2b01,reg2=0x10cd/0xffff,nw_src=85.85.85.1,nw_dst=85.85.85.1,tp_dst=8501 actions=load:0x1->NXM_NX_REG10[[7]],learn(table=69,delete_learned,OXM_OF_METADATA[[]],eth_type=0x800,NXM_OF_IP_SRC[[]],ip_dst=43.43.43.1,nw_proto=6,NXM_OF_TCP_SRC[[]]=NXM_OF_TCP_DST[[]],load:0x1->NXM_NX_REG10[[7]])
+ table=68, priority=100,ct_mark=0x2/0x2,tcp,reg1=0x2b2b2b02,reg2=0x10ce/0xffff,nw_src=85.85.85.21,nw_dst=85.85.85.21,tp_dst=8502 actions=load:0x1->NXM_NX_REG10[[7]],learn(table=69,delete_learned,OXM_OF_METADATA[[]],eth_type=0x800,NXM_OF_IP_SRC[[]],ip_dst=43.43.43.2,nw_proto=6,NXM_OF_TCP_SRC[[]]=NXM_OF_TCP_DST[[]],load:0x1->NXM_NX_REG10[[7]])
+ table=68, priority=100,ct_mark=0x2/0x2,tcp,reg1=0x2b2b2b02,reg2=0x10ce/0xffff,nw_src=85.85.85.22,nw_dst=85.85.85.22,tp_dst=8502 actions=load:0x1->NXM_NX_REG10[[7]],learn(table=69,delete_learned,OXM_OF_METADATA[[]],eth_type=0x800,NXM_OF_IP_SRC[[]],ip_dst=43.43.43.2,nw_proto=6,NXM_OF_TCP_SRC[[]]=NXM_OF_TCP_DST[[]],load:0x1->NXM_NX_REG10[[7]])
+ table=68, priority=100,ct_mark=0x2/0x2,tcp,reg1=0x2b2b2b03,reg2=0x10cf/0xffff,nw_src=85.85.85.31,nw_dst=85.85.85.31,tp_dst=8503 actions=load:0x1->NXM_NX_REG10[[7]],learn(table=69,delete_learned,OXM_OF_METADATA[[]],eth_type=0x800,NXM_OF_IP_SRC[[]],ip_dst=43.43.43.3,nw_proto=6,NXM_OF_TCP_SRC[[]]=NXM_OF_TCP_DST[[]],load:0x1->NXM_NX_REG10[[7]])
+ table=68, priority=100,ct_mark=0x2/0x2,tcp,reg1=0x2b2b2b03,reg2=0x10cf/0xffff,nw_src=85.85.85.32,nw_dst=85.85.85.32,tp_dst=8503 actions=load:0x1->NXM_NX_REG10[[7]],learn(table=69,delete_learned,OXM_OF_METADATA[[]],eth_type=0x800,NXM_OF_IP_SRC[[]],ip_dst=43.43.43.3,nw_proto=6,NXM_OF_TCP_SRC[[]]=NXM_OF_TCP_DST[[]],load:0x1->NXM_NX_REG10[[7]])
+])
+
+dnl Change Chassis_Template_Var mappings
+check ovn-nbctl --wait=hv set Chassis_Template_Var hv1 \
+    variables:VIP1='42.42.42.1' variables:VPORT1='4201' \
+    variables:BACKENDS1='84.84.84.1:8401' \
+    variables:VIP2='42.42.42.2' variables:VPORT2='4202' \
+    variables:BACKENDS21='84.84.84.21:8402' \
+    variables:BACKENDS22='84.84.84.22:8402' \
+    variables:VIP3='42.42.42.3' variables:VPORT3='4203' \
+    variables:BACKENDS31='84.84.84.31' \
+    variables:BACKENDS32='84.84.84.32' \
+    variables:BPORT1='8403' variables:BPORT2='8403'
+
+dnl Ensure the LBs are translated to OpenFlow.
+as hv1
+AT_CHECK([ovs-ofctl dump-groups br-int | grep 'nat(dst=84.84.84.1:8401)' -c], [0], [dnl
+1
+])
+AT_CHECK([ovs-ofctl dump-groups br-int | grep 'nat(dst=84.84.84.21:8402)' -c], [0], [dnl
+1
+])
+AT_CHECK([ovs-ofctl dump-groups br-int | grep 'nat(dst=84.84.84.22:8402)' -c], [0], [dnl
+1
+])
+AT_CHECK([ovs-ofctl dump-groups br-int | grep 'nat(dst=84.84.84.31:8403)' -c], [0], [dnl
+1
+])
+AT_CHECK([ovs-ofctl dump-groups br-int | grep 'nat(dst=84.84.84.32:8403)' -c], [0], [dnl
+1
+])
+
+dnl Ensure hairpin flows are correct.
+as hv1
+AT_CHECK([ovs-ofctl dump-flows br-int | grep table=68 | ofctl_strip_all], [0], [dnl
+ table=68, priority=100,ct_mark=0x2/0x2,tcp,reg1=0x2a2a2a01,reg2=0x1069/0xffff,nw_src=84.84.84.1,nw_dst=84.84.84.1,tp_dst=8401 actions=load:0x1->NXM_NX_REG10[[7]],learn(table=69,delete_learned,OXM_OF_METADATA[[]],eth_type=0x800,NXM_OF_IP_SRC[[]],ip_dst=42.42.42.1,nw_proto=6,NXM_OF_TCP_SRC[[]]=NXM_OF_TCP_DST[[]],load:0x1->NXM_NX_REG10[[7]])
+ table=68, priority=100,ct_mark=0x2/0x2,tcp,reg1=0x2a2a2a02,reg2=0x106a/0xffff,nw_src=84.84.84.21,nw_dst=84.84.84.21,tp_dst=8402 actions=load:0x1->NXM_NX_REG10[[7]],learn(table=69,delete_learned,OXM_OF_METADATA[[]],eth_type=0x800,NXM_OF_IP_SRC[[]],ip_dst=42.42.42.2,nw_proto=6,NXM_OF_TCP_SRC[[]]=NXM_OF_TCP_DST[[]],load:0x1->NXM_NX_REG10[[7]])
+ table=68, priority=100,ct_mark=0x2/0x2,tcp,reg1=0x2a2a2a02,reg2=0x106a/0xffff,nw_src=84.84.84.22,nw_dst=84.84.84.22,tp_dst=8402 actions=load:0x1->NXM_NX_REG10[[7]],learn(table=69,delete_learned,OXM_OF_METADATA[[]],eth_type=0x800,NXM_OF_IP_SRC[[]],ip_dst=42.42.42.2,nw_proto=6,NXM_OF_TCP_SRC[[]]=NXM_OF_TCP_DST[[]],load:0x1->NXM_NX_REG10[[7]])
+ table=68, priority=100,ct_mark=0x2/0x2,tcp,reg1=0x2a2a2a03,reg2=0x106b/0xffff,nw_src=84.84.84.31,nw_dst=84.84.84.31,tp_dst=8403 actions=load:0x1->NXM_NX_REG10[[7]],learn(table=69,delete_learned,OXM_OF_METADATA[[]],eth_type=0x800,NXM_OF_IP_SRC[[]],ip_dst=42.42.42.3,nw_proto=6,NXM_OF_TCP_SRC[[]]=NXM_OF_TCP_DST[[]],load:0x1->NXM_NX_REG10[[7]])
+ table=68, priority=100,ct_mark=0x2/0x2,tcp,reg1=0x2a2a2a03,reg2=0x106b/0xffff,nw_src=84.84.84.32,nw_dst=84.84.84.32,tp_dst=8403 actions=load:0x1->NXM_NX_REG10[[7]],learn(table=69,delete_learned,OXM_OF_METADATA[[]],eth_type=0x800,NXM_OF_IP_SRC[[]],ip_dst=42.42.42.3,nw_proto=6,NXM_OF_TCP_SRC[[]]=NXM_OF_TCP_DST[[]],load:0x1->NXM_NX_REG10[[7]])
+])
+
+dnl Remove Chassis_Template_Variables and check that everything is
+dnl removed from OpenFlow.
+check ovn-nbctl --wait=hv clear Chassis_Template_Var hv1 variables
+
+as hv1
+AT_CHECK([ovs-ofctl dump-groups br-int | grep 'nat'], [1], [])
+
+as hv1
+AT_CHECK([ovs-ofctl dump-flows br-int | grep table=68 | ofctl_strip_all], [0], [])
+
+OVN_CLEANUP([hv1])
+AT_CLEANUP
+])
diff --git a/tests/system-ovn.at b/tests/system-ovn.at
index 20c0584151..8d0ec68479 100644
--- a/tests/system-ovn.at
+++ b/tests/system-ovn.at
@@ -8597,3 +8597,186 @@  OVS_TRAFFIC_VSWITCHD_STOP(["/failed to query port patch-.*/d
 /connection dropped.*/d"])
 AT_CLEANUP
 ])
+
+OVN_FOR_EACH_NORTHD([
+AT_SETUP([load-balancer template IPv4])
+AT_SKIP_IF([test $HAVE_NC = no])
+AT_KEYWORDS([ovnlb templates])
+
+CHECK_CONNTRACK()
+CHECK_CONNTRACK_NAT()
+ovn_start
+OVS_TRAFFIC_VSWITCHD_START()
+OVS_CHECK_CT_ZERO_SNAT()
+ADD_BR([br-int])
+
+# Set external-ids in br-int needed for ovn-controller
+ovs-vsctl \
+        -- set Open_vSwitch . external-ids:system-id=hv1 \
+        -- set Open_vSwitch . external-ids:ovn-remote=unix:$ovs_base/ovn-sb/ovn-sb.sock \
+        -- set Open_vSwitch . external-ids:ovn-encap-type=geneve \
+        -- set Open_vSwitch . external-ids:ovn-encap-ip=169.0.0.1 \
+        -- set bridge br-int fail-mode=secure other-config:disable-in-band=true
+
+# Start ovn-controller
+start_daemon ovn-controller
+
+# Logical network:
+# VM1 -- LS1 -- GW-Router -- LS2 -- VM3
+#         |
+# VM2 ----+
+#
+# A templated load balancer applied on LS1 and GW-Router with
+# VM1 as backend.  The VIP should be accessible from both VM2 and VM3.
+
+check ovn-nbctl                                                   \
+    -- lr-add rtr                                                 \
+    -- set Logical_Router rtr options:chassis=hv1                 \
+    -- lrp-add rtr rtr-ls1 00:00:00:00:01:00 42.42.42.1/24        \
+    -- lrp-add rtr rtr-ls2 00:00:00:00:02:00 43.43.43.1/24        \
+    -- ls-add ls1                                                 \
+    -- lsp-add ls1 ls1-rtr                                        \
+    -- lsp-set-addresses ls1-rtr 00:00:00:00:01:00                \
+    -- lsp-set-type ls1-rtr router                                \
+    -- lsp-set-options ls1-rtr router-port=rtr-ls1                \
+    -- lsp-add ls1 vm1 -- lsp-set-addresses vm1 00:00:00:00:00:01 \
+    -- lsp-add ls1 vm2 -- lsp-set-addresses vm2 00:00:00:00:00:02 \
+    -- ls-add ls2                                                 \
+    -- lsp-add ls2 ls2-rtr                                        \
+    -- lsp-set-addresses ls2-rtr 00:00:00:00:02:00                \
+    -- lsp-set-type ls2-rtr router                                \
+    -- lsp-set-options ls2-rtr router-port=rtr-ls2                \
+    -- lsp-add ls2 vm3 -- lsp-set-addresses vm3 00:00:00:00:00:03
+
+# Add a template LB that eventually expands to:
+# VIP=66.66.66.66:666 backends=42.42.42.2:4242 proto=tcp
+
+AT_CHECK([ovn-nbctl -- create chassis_template_var chassis="hv1" variables="{vip=66.66.66.66,vport=666,backends=\"42.42.42.2:4242\"}"],
+         [0], [ignore])
+
+check ovn-nbctl --template lb-add lb-test "^vip:^vport" "^backends" tcp \
+    -- ls-lb-add ls1 lb-test                                            \
+    -- lr-lb-add rtr lb-test
+
+ADD_NAMESPACES(vm1)
+ADD_VETH(vm1, vm1, br-int, "42.42.42.2/24", "00:00:00:00:00:01", "42.42.42.1")
+
+ADD_NAMESPACES(vm2)
+ADD_VETH(vm2, vm2, br-int, "42.42.42.3/24", "00:00:00:00:00:02", "42.42.42.1")
+
+ADD_NAMESPACES(vm3)
+ADD_VETH(vm3, vm3, br-int, "43.43.43.2/24", "00:00:00:00:00:03", "43.43.43.1")
+
+# Wait for ovn-controller to catch up.
+wait_for_ports_up
+check ovn-nbctl --wait=hv sync
+
+AT_CHECK([ovn-appctl -t ovn-controller debug/dump-local-template-vars | sort], [0], [dnl
+Local template vars:
+name: 'backends' value: '42.42.42.2:4242'
+name: 'vip' value: '66.66.66.66'
+name: 'vport' value: '666'
+])
+
+# Start IPv4 TCP server on vm1.
+NETNS_DAEMONIZE([vm1], [nc -k -l 42.42.42.2 4242], [nc-vm1.pid])
+
+# Make sure connecting to the VIP works.
+NS_CHECK_EXEC([vm2], [nc 66.66.66.66 666 -z], [0], [ignore], [ignore])
+NS_CHECK_EXEC([vm3], [nc 66.66.66.66 666 -z], [0], [ignore], [ignore])
+
+AT_CLEANUP
+])
+
+OVN_FOR_EACH_NORTHD([
+AT_SETUP([load-balancer template IPv6])
+AT_SKIP_IF([test $HAVE_NC = no])
+AT_KEYWORDS([ovnlb templates])
+
+CHECK_CONNTRACK()
+CHECK_CONNTRACK_NAT()
+ovn_start
+OVS_TRAFFIC_VSWITCHD_START()
+OVS_CHECK_CT_ZERO_SNAT()
+ADD_BR([br-int])
+
+# Set external-ids in br-int needed for ovn-controller
+ovs-vsctl \
+        -- set Open_vSwitch . external-ids:system-id=hv1 \
+        -- set Open_vSwitch . external-ids:ovn-remote=unix:$ovs_base/ovn-sb/ovn-sb.sock \
+        -- set Open_vSwitch . external-ids:ovn-encap-type=geneve \
+        -- set Open_vSwitch . external-ids:ovn-encap-ip=169.0.0.1 \
+        -- set bridge br-int fail-mode=secure other-config:disable-in-band=true
+
+# Start ovn-controller
+start_daemon ovn-controller
+
+# Logical network:
+# VM1 -- LS1 -- GW-Router -- LS2 -- VM3
+#         |
+# VM2 ----+
+#
+# A templated load balancer applied on LS1 and GW-Router with
+# VM1 as backend.  The VIP should be accessible from both VM2 and VM3.
+
+check ovn-nbctl                                                   \
+    -- lr-add rtr                                                 \
+    -- set Logical_Router rtr options:chassis=hv1                 \
+    -- lrp-add rtr rtr-ls1 00:00:00:00:01:00 4242::1/64           \
+    -- lrp-add rtr rtr-ls2 00:00:00:00:02:00 4343::1/64           \
+    -- ls-add ls1                                                 \
+    -- lsp-add ls1 ls1-rtr                                        \
+    -- lsp-set-addresses ls1-rtr 00:00:00:00:01:00                \
+    -- lsp-set-type ls1-rtr router                                \
+    -- lsp-set-options ls1-rtr router-port=rtr-ls1                \
+    -- lsp-add ls1 vm1 -- lsp-set-addresses vm1 00:00:00:00:00:01 \
+    -- lsp-add ls1 vm2 -- lsp-set-addresses vm2 00:00:00:00:00:02 \
+    -- ls-add ls2                                                 \
+    -- lsp-add ls2 ls2-rtr                                        \
+    -- lsp-set-addresses ls2-rtr 00:00:00:00:02:00                \
+    -- lsp-set-type ls2-rtr router                                \
+    -- lsp-set-options ls2-rtr router-port=rtr-ls2                \
+    -- lsp-add ls2 vm3 -- lsp-set-addresses vm3 00:00:00:00:00:03
+
+# Add a template LB that eventually expands to:
+# VIP=6666::1 backends=[4242::2]:4242 proto=tcp
+
+AT_CHECK([ovn-nbctl -- create chassis_template_var chassis="hv1" variables="{vip=\"6666::1\",vport=666,backends=\"[[4242::2]]:4242\"}"],
+         [0], [ignore])
+
+check ovn-nbctl --template lb-add lb-test "^vip:^vport" "^backends" tcp ipv6 \
+    -- ls-lb-add ls1 lb-test                                                 \
+    -- lr-lb-add rtr lb-test
+
+ADD_NAMESPACES(vm1)
+ADD_VETH(vm1, vm1, br-int, "4242::2/64", "00:00:00:00:00:01", "4242::1")
+OVS_WAIT_UNTIL([test "$(ip netns exec vm1 ip a | grep 4242::2 | grep tentative)" = ""])
+
+ADD_NAMESPACES(vm2)
+ADD_VETH(vm2, vm2, br-int, "4242::3/64", "00:00:00:00:00:02", "4242::1")
+OVS_WAIT_UNTIL([test "$(ip netns exec vm2 ip a | grep 4242::3 | grep tentative)" = ""])
+
+ADD_NAMESPACES(vm3)
+ADD_VETH(vm3, vm3, br-int, "4343::2/64", "00:00:00:00:00:03", "4343::1")
+OVS_WAIT_UNTIL([test "$(ip netns exec vm3 ip a | grep 4343::2 | grep tentative)" = ""])
+
+# Wait for ovn-controller to catch up.
+wait_for_ports_up
+check ovn-nbctl --wait=hv sync
+
+AT_CHECK([ovn-appctl -t ovn-controller debug/dump-local-template-vars | sort], [0], [dnl
+Local template vars:
+name: 'backends' value: '[[4242::2]]:4242'
+name: 'vip' value: '6666::1'
+name: 'vport' value: '666'
+])
+
+# Start IPv6 TCP server on vm1.
+NETNS_DAEMONIZE([vm1], [nc -k -l 4242::2 4242], [nc-vm1.pid])
+
+# Make sure connecting to the VIP works.
+NS_CHECK_EXEC([vm2], [nc 6666::1 666 -z], [0], [ignore], [ignore])
+NS_CHECK_EXEC([vm3], [nc 6666::1 666 -z], [0], [ignore], [ignore])
+
+AT_CLEANUP
+])
diff --git a/utilities/ovn-nbctl.c b/utilities/ovn-nbctl.c
index d2dee6b31c..dea7218f21 100644
--- a/utilities/ovn-nbctl.c
+++ b/utilities/ovn-nbctl.c
@@ -28,6 +28,7 @@ 
 #include "openvswitch/json.h"
 #include "lib/acl-log.h"
 #include "lib/copp.h"
+#include "lib/lb.h"
 #include "lib/ovn-nb-idl.h"
 #include "lib/ovn-util.h"
 #include "memory.h"
@@ -2837,6 +2838,7 @@  nbctl_lb_add(struct ctl_context *ctx)
     bool empty_backend_rej = shash_find(&ctx->options, "--reject") != NULL;
     bool empty_backend_event = shash_find(&ctx->options, "--event") != NULL;
     bool add_route = shash_find(&ctx->options, "--add-route") != NULL;
+    bool template = shash_find(&ctx->options, "--template") != NULL;
 
     if (empty_backend_event && empty_backend_rej) {
             ctl_error(ctx,
@@ -2844,10 +2846,12 @@  nbctl_lb_add(struct ctl_context *ctx)
             return;
     }
 
+    const char *lb_address_family_str = "ipv4";
+    int lb_address_family = AF_INET;
     const char *lb_proto;
     bool is_update_proto = false;
 
-    if (ctx->argc == 4) {
+    if (ctx->argc <= 4) {
         /* Default protocol. */
         lb_proto = "tcp";
     } else {
@@ -2863,79 +2867,61 @@  nbctl_lb_add(struct ctl_context *ctx)
         }
     }
 
-    struct sockaddr_storage ss_vip;
-    if (!inet_parse_active(lb_vip, 0, &ss_vip, false, NULL)) {
-        ctl_error(ctx, "%s: should be an IP address (or an IP address "
-                  "and a port number with : as a separator).", lb_vip);
-        return;
-    }
-
-    struct ds lb_vip_normalized_ds = DS_EMPTY_INITIALIZER;
-    uint16_t lb_vip_port = ss_get_port(&ss_vip);
-    if (lb_vip_port) {
-        ss_format_address(&ss_vip, &lb_vip_normalized_ds);
-        ds_put_format(&lb_vip_normalized_ds, ":%d", lb_vip_port);
-    } else {
-        ss_format_address_nobracks(&ss_vip, &lb_vip_normalized_ds);
-    }
-    const char *lb_vip_normalized = ds_cstr(&lb_vip_normalized_ds);
+    if (ctx->argc > 5) {
+        lb_address_family_str = ctx->argv[5];
+        lb_address_family = !strcmp(lb_address_family_str, "ipv4")
+                            ? AF_INET : AF_INET6;
 
-    if (!lb_vip_port && is_update_proto) {
-        ds_destroy(&lb_vip_normalized_ds);
-        ctl_error(ctx, "Protocol is unnecessary when no port of vip "
-                  "is given.");
-        return;
     }
 
-    char *token = NULL, *save_ptr = NULL;
+    struct ds lb_vip_normalized = DS_EMPTY_INITIALIZER;
     struct ds lb_ips_new = DS_EMPTY_INITIALIZER;
-    for (token = strtok_r(lb_ips, ",", &save_ptr);
-            token != NULL; token = strtok_r(NULL, ",", &save_ptr)) {
-        struct sockaddr_storage ss_dst;
+    struct ovn_lb_vip lb_vip_parsed;
 
-        if (lb_vip_port) {
-            if (!inet_parse_active(token, -1, &ss_dst, false, NULL)) {
-                ctl_error(ctx, "%s: should be an IP address and a port "
-                          "number with : as a separator.", token);
-                goto out;
-            }
-        } else {
-            if (!inet_parse_address(token, &ss_dst)) {
-                ctl_error(ctx, "%s: should be an IP address.", token);
-                goto out;
-            }
-        }
+    char *error = ovn_lb_vip_init(&lb_vip_parsed, lb_vip, lb_ips, template,
+                                  lb_address_family);
+    if (error) {
+        ctl_error(ctx, "%s", error);
+        ovn_lb_vip_destroy(&lb_vip_parsed);
+        free(error);
+        return;
+    }
 
-        if (ss_vip.ss_family != ss_dst.ss_family) {
-            ctl_error(ctx, "%s: IP address family is different from VIP %s.",
-                      token, lb_vip_normalized);
-            goto out;
-        }
-        ds_put_format(&lb_ips_new, "%s%s",
-                lb_ips_new.length ? "," : "", token);
+    if (is_update_proto && !lb_vip_parsed.port_str) {
+        ctl_error(ctx, "Protocol is unnecessary when no port of vip is "
+                       "given.");
+        ovn_lb_vip_destroy(&lb_vip_parsed);
+        return;
     }
 
+    ovn_lb_vip_format(&lb_vip_parsed, &lb_vip_normalized, template);
+    ovn_lb_vip_backends_format(&lb_vip_parsed, &lb_ips_new, template);
+    ovn_lb_vip_destroy(&lb_vip_parsed);
+
     const struct nbrec_load_balancer *lb = NULL;
     if (!add_duplicate) {
-        char *error = lb_by_name_or_uuid(ctx, lb_name, false, &lb);
+        error = lb_by_name_or_uuid(ctx, lb_name, false, &lb);
         if (error) {
             ctx->error = error;
             goto out;
         }
         if (lb) {
-            if (smap_get(&lb->vips, lb_vip_normalized)) {
+            if (smap_get(&lb->vips, ds_cstr(&lb_vip_normalized))) {
                 if (!may_exist) {
                     ctl_error(ctx, "%s: a load balancer with this vip (%s) "
-                              "already exists", lb_name, lb_vip_normalized);
+                              "already exists", lb_name,
+                              ds_cstr(&lb_vip_normalized));
                     goto out;
                 }
                 /* Update the vips. */
                 smap_replace(CONST_CAST(struct smap *, &lb->vips),
-                        lb_vip_normalized, ds_cstr(&lb_ips_new));
+                             ds_cstr(&lb_vip_normalized),
+                             ds_cstr(&lb_ips_new));
             } else {
                 /* Add the new vips. */
                 smap_add(CONST_CAST(struct smap *, &lb->vips),
-                        lb_vip_normalized, ds_cstr(&lb_ips_new));
+                         ds_cstr(&lb_vip_normalized),
+                         ds_cstr(&lb_ips_new));
             }
 
             /* Update the load balancer. */
@@ -2954,7 +2940,7 @@  nbctl_lb_add(struct ctl_context *ctx)
     nbrec_load_balancer_set_name(lb, lb_name);
     nbrec_load_balancer_set_protocol(lb, lb_proto);
     smap_add(CONST_CAST(struct smap *, &lb->vips),
-            lb_vip_normalized, ds_cstr(&lb_ips_new));
+             ds_cstr(&lb_vip_normalized), ds_cstr(&lb_ips_new));
     nbrec_load_balancer_set_vips(lb, &lb->vips);
     struct smap options = SMAP_INITIALIZER(&options);
     if (empty_backend_rej) {
@@ -2966,12 +2952,16 @@  nbctl_lb_add(struct ctl_context *ctx)
     if (add_route) {
         smap_add(&options, "add_route", "true");
     }
+    if (template) {
+        smap_add(&options, "template", "true");
+        smap_add(&options, "address-family", lb_address_family_str);
+    }
     nbrec_load_balancer_set_options(lb, &options);
     smap_destroy(&options);
 out:
     ds_destroy(&lb_ips_new);
 
-    ds_destroy(&lb_vip_normalized_ds);
+    ds_destroy(&lb_vip_normalized);
 }
 
 static void
@@ -3025,6 +3015,7 @@  static void
 nbctl_pre_lb_list(struct ctl_context *ctx)
 {
     ovsdb_idl_add_column(ctx->idl, &nbrec_load_balancer_col_name);
+    ovsdb_idl_add_column(ctx->idl, &nbrec_load_balancer_col_options);
     ovsdb_idl_add_column(ctx->idl, &nbrec_load_balancer_col_protocol);
     ovsdb_idl_add_column(ctx->idl, &nbrec_load_balancer_col_vips);
 }
@@ -3033,6 +3024,7 @@  static void
 lb_info_add_smap(const struct nbrec_load_balancer *lb,
                  struct smap *lbs, int vip_width)
 {
+    bool template = smap_get_bool(&lb->options, "template", false);
     const struct smap_node **nodes = smap_sort(&lb->vips);
     if (!nodes) {
         return;
@@ -3041,13 +3033,24 @@  lb_info_add_smap(const struct nbrec_load_balancer *lb,
     struct ds val = DS_EMPTY_INITIALIZER;
     for (size_t i = 0; i < smap_count(&lb->vips); i++) {
         const struct smap_node *node = nodes[i];
+        const char *protocol = lb->protocol;
 
-        struct sockaddr_storage ss;
-        if (!inet_parse_active(node->key, 0, &ss, false, NULL)) {
-            continue;
+        if (!template) {
+            struct sockaddr_storage ss;
+            if (!inet_parse_active(node->key, 0, &ss, false, NULL)) {
+                continue;
+            }
+            protocol = ss_get_port(&ss) ? lb->protocol : "";
+        } else {
+            if (!lb->protocol) {
+                VLOG_WARN("Load Balancer "UUID_FMT" (%s) is a template and "
+                          "misses protocol", UUID_ARGS(&lb->header_.uuid),
+                          lb->name);
+                continue;
+            }
+            protocol = lb->protocol;
         }
 
-        char *protocol = ss_get_port(&ss) ? lb->protocol : "";
         if (i == 0) {
             ds_put_format(&val, UUID_FMT "    %-20.16s%-11.7s%-*.*s%s",
                           UUID_ARGS(&lb->header_.uuid),
@@ -3239,6 +3242,7 @@  nbctl_pre_lr_lb_list(struct ctl_context *ctx)
                          &nbrec_logical_router_col_load_balancer_group);
 
     ovsdb_idl_add_column(ctx->idl, &nbrec_load_balancer_col_name);
+    ovsdb_idl_add_column(ctx->idl, &nbrec_load_balancer_col_options);
     ovsdb_idl_add_column(ctx->idl, &nbrec_load_balancer_col_protocol);
     ovsdb_idl_add_column(ctx->idl, &nbrec_load_balancer_col_vips);
 
@@ -3402,6 +3406,7 @@  nbctl_pre_ls_lb_list(struct ctl_context *ctx)
                          &nbrec_logical_switch_col_load_balancer_group);
 
     ovsdb_idl_add_column(ctx->idl, &nbrec_load_balancer_col_name);
+    ovsdb_idl_add_column(ctx->idl, &nbrec_load_balancer_col_options);
     ovsdb_idl_add_column(ctx->idl, &nbrec_load_balancer_col_protocol);
     ovsdb_idl_add_column(ctx->idl, &nbrec_load_balancer_col_vips);
 
@@ -7472,9 +7477,10 @@  static const struct ctl_command_syntax nbctl_commands[] = {
       nbctl_pre_lr_nat_set_ext_ips, nbctl_lr_nat_set_ext_ips,
       NULL, "--is-exempted", RW},
     /* load balancer commands. */
-    { "lb-add", 3, 4, "LB VIP[:PORT] IP[:PORT]... [PROTOCOL]",
+    { "lb-add", 3, 5, "LB VIP[:PORT] IP[:PORT]... [PROTOCOL] [ADDRESS_FAMILY]",
       nbctl_pre_lb_add, nbctl_lb_add, NULL,
-      "--may-exist,--add-duplicate,--reject,--event,--add-route", RW },
+      "--may-exist,--add-duplicate,--reject,--event,--add-route,--template",
+      RW },
     { "lb-del", 1, 2, "LB [VIP]", nbctl_pre_lb_del, nbctl_lb_del, NULL,
         "--if-exists", RW },
     { "lb-list", 0, 1, "[LB]", nbctl_pre_lb_list, nbctl_lb_list, NULL, "", RO },