diff --git a/neutron/agent/linux/keepalived.py b/neutron/agent/linux/keepalived.py
index 910d0be96e2..a42e42ad1f7 100644
--- a/neutron/agent/linux/keepalived.py
+++ b/neutron/agent/linux/keepalived.py
@@ -152,6 +152,11 @@ def build_config(self):
                 LOG.warning("keepalived_use_no_track cfg option is True but "
                             "keepalived on host seems to not support this "
                             "option")
+        # NOTE(mstinsky): neutron and keepalived are adding the same routes on
+        # primary routers. With this we ensure that both are adding the routes
+        # with the same procotol and prevent duplicated routes which result in
+        # neutron exception for ip route commands.
+        output += ' protocol static'
         return output
 
 
diff --git a/neutron/common/ovn/utils.py b/neutron/common/ovn/utils.py
index 011849b07de..9031b501fe3 100644
--- a/neutron/common/ovn/utils.py
+++ b/neutron/common/ovn/utils.py
@@ -625,8 +625,8 @@ def compute_address_pairs_diff(ovn_port, neutron_port):
 
 def get_ovn_cms_options(chassis):
     """Return the list of CMS options in a Chassis."""
-    return [opt.strip() for opt in chassis.external_ids.get(
-            constants.OVN_CMS_OPTIONS, '').split(',')]
+    return [opt.strip() for opt in get_ovn_chassis_other_config(chassis).get(
+        constants.OVN_CMS_OPTIONS, '').split(',')]
 
 
 def is_gateway_chassis(chassis):
@@ -815,3 +815,11 @@ def create_neutron_pg_drop():
         }]
 
     OvsdbClientTransactCommand.run(command)
+
+
+def get_ovn_chassis_other_config(chassis):
+    # NOTE(ralonsoh): LP#1990229 to be removed when min OVN version is 22.09
+    try:
+        return chassis.other_config
+    except AttributeError:
+        return chassis.external_ids
diff --git a/neutron/db/l3_db.py b/neutron/db/l3_db.py
index 96a304dae12..a21b8131829 100644
--- a/neutron/db/l3_db.py
+++ b/neutron/db/l3_db.py
@@ -1025,10 +1025,15 @@ def _add_router_port(self, context, port_id, router, device_owner):
                     subnets_id.extend([fixed_ip['subnet_id']
                                        for fixed_ip in port['fixed_ips']])
                 else:
-                    raise l3_exc.RouterInterfaceNotFound(
-                        router_id=router.id, port_id=rp.port_id)
-
-            if subnets_id:
+                    # due to race conditions maybe the port under analysis is
+                    # deleted, so instead returning a RouterInterfaceNotFound
+                    # we continue the analysis avoiding that port
+                    LOG.debug("Port %s could not be found, it might have been "
+                              "deleted concurrently. Will not be checked for "
+                              "an overlapping router interface.",
+                              rp.port_id)
+
+            if len(subnets_id) > 1:
                 id_filter = {'id': subnets_id}
                 subnets = self._core_plugin.get_subnets(context.elevated(),
                                                         filters=id_filter)
diff --git a/neutron/plugins/ml2/drivers/ovn/agent/neutron_agent.py b/neutron/plugins/ml2/drivers/ovn/agent/neutron_agent.py
index d6b70201820..c0a234019bf 100644
--- a/neutron/plugins/ml2/drivers/ovn/agent/neutron_agent.py
+++ b/neutron/plugins/ml2/drivers/ovn/agent/neutron_agent.py
@@ -89,7 +89,8 @@ def as_dict(self):
             'configurations': {
                 'chassis_name': self.chassis.name,
                 'bridge-mappings':
-                    self.chassis.external_ids.get('ovn-bridge-mappings', '')},
+                    ovn_utils.get_ovn_chassis_other_config(self.chassis).get(
+                        'ovn-bridge-mappings', '')},
             'start_flag': True,
             'agent_type': self.agent_type,
             'id': self.agent_id,
@@ -141,9 +142,9 @@ class ControllerAgent(NeutronAgent):
 
     @staticmethod  # it is by default, but this makes pep8 happy
     def __new__(cls, chassis_private, driver):
-        external_ids = cls.chassis_from_private(chassis_private).external_ids
-        if ('enable-chassis-as-gw' in
-                external_ids.get('ovn-cms-options', [])):
+        _chassis = cls.chassis_from_private(chassis_private)
+        other_config = ovn_utils.get_ovn_chassis_other_config(_chassis)
+        if 'enable-chassis-as-gw' in other_config.get('ovn-cms-options', []):
             cls = ControllerGatewayAgent
         return super().__new__(cls)
 
@@ -166,8 +167,9 @@ def description(self):
 
     def update(self, chassis_private, clear_down=False):
         super().update(chassis_private, clear_down)
-        external_ids = self.chassis_from_private(chassis_private).external_ids
-        if 'enable-chassis-as-gw' in external_ids.get('ovn-cms-options', []):
+        _chassis = self.chassis_from_private(chassis_private)
+        other_config = ovn_utils.get_ovn_chassis_other_config(_chassis)
+        if 'enable-chassis-as-gw' in other_config.get('ovn-cms-options', []):
             self.__class__ = ControllerGatewayAgent
 
 
@@ -176,9 +178,10 @@ class ControllerGatewayAgent(ControllerAgent):
 
     def update(self, chassis_private, clear_down=False):
         super().update(chassis_private, clear_down)
-        external_ids = self.chassis_from_private(chassis_private).external_ids
+        _chassis = self.chassis_from_private(chassis_private)
+        other_config = ovn_utils.get_ovn_chassis_other_config(_chassis)
         if ('enable-chassis-as-gw' not in
-                external_ids.get('ovn-cms-options', [])):
+                other_config.get('ovn-cms-options', [])):
             self.__class__ = ControllerAgent
 
 
diff --git a/neutron/plugins/ml2/drivers/ovn/mech_driver/mech_driver.py b/neutron/plugins/ml2/drivers/ovn/mech_driver/mech_driver.py
index 6f6faca40be..37118ec0894 100644
--- a/neutron/plugins/ml2/drivers/ovn/mech_driver/mech_driver.py
+++ b/neutron/plugins/ml2/drivers/ovn/mech_driver/mech_driver.py
@@ -179,7 +179,8 @@ def sb_ovn(self, val):
     def get_supported_vif_types(self):
         vif_types = set()
         for ch in self.sb_ovn.chassis_list().execute(check_error=True):
-            dp_type = ch.external_ids.get('datapath-type', '')
+            other_config = ovn_utils.get_ovn_chassis_other_config(ch)
+            dp_type = other_config.get('datapath-type', '')
             if dp_type == ovn_const.CHASSIS_DATAPATH_NETDEV:
                 vif_types.add(portbindings.VIF_TYPE_VHOST_USER)
             else:
@@ -961,8 +962,9 @@ def bind_port(self, context):
                                       'agent': agent})
             return
         chassis = agent.chassis
-        datapath_type = chassis.external_ids.get('datapath-type', '')
-        iface_types = chassis.external_ids.get('iface-types', '')
+        other_config = ovn_utils.get_ovn_chassis_other_config(chassis)
+        datapath_type = other_config.get('datapath-type', '')
+        iface_types = other_config.get('iface-types', '')
         iface_types = iface_types.split(',') if iface_types else []
         chassis_physnets = self.sb_ovn._get_chassis_physnets(chassis)
         for segment_to_bind in context.segments_to_bind:
diff --git a/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/extensions/placement.py b/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/extensions/placement.py
index eab14543263..f372807fcad 100644
--- a/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/extensions/placement.py
+++ b/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/extensions/placement.py
@@ -42,7 +42,8 @@ def _parse_ovn_cms_options(chassis):
 
 
 def _parse_bridge_mappings(chassis):
-    bridge_mappings = chassis.external_ids.get('ovn-bridge-mappings', '')
+    other_config = ovn_utils.get_ovn_chassis_other_config(chassis)
+    bridge_mappings = other_config.get('ovn-bridge-mappings', '')
     bridge_mappings = helpers.parse_mappings(bridge_mappings.split(','),
                                              unique_values=False)
     return {k: [v] for k, v in bridge_mappings.items()}
diff --git a/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/impl_idl_ovn.py b/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/impl_idl_ovn.py
index c1ff8626c34..250936252ee 100644
--- a/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/impl_idl_ovn.py
+++ b/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/impl_idl_ovn.py
@@ -830,7 +830,8 @@ def from_worker(cls, worker_class, driver=None):
         return cls(conn)
 
     def _get_chassis_physnets(self, chassis):
-        bridge_mappings = chassis.external_ids.get('ovn-bridge-mappings', '')
+        other_config = utils.get_ovn_chassis_other_config(chassis)
+        bridge_mappings = other_config.get('ovn-bridge-mappings', '')
         mapping_dict = helpers.parse_mappings(bridge_mappings.split(','))
         return list(mapping_dict.keys())
 
@@ -848,7 +849,8 @@ def get_gateway_chassis_from_cms_options(self, name_only=True):
         return [ch.name if name_only else ch
                 for ch in self.chassis_list().execute(check_error=True)
                 if ovn_const.CMS_OPT_CHASSIS_AS_GW in
-                ch.external_ids.get(ovn_const.OVN_CMS_OPTIONS, '').split(',')]
+                utils.get_ovn_chassis_other_config(ch).get(
+                    ovn_const.OVN_CMS_OPTIONS, '').split(',')]
 
     def get_chassis_and_physnets(self):
         chassis_info_dict = {}
@@ -867,7 +869,7 @@ def get_chassis_by_card_serial_from_cms_options(self,
             if ('{}={}'
                 .format(ovn_const.CMS_OPT_CARD_SERIAL_NUMBER,
                         card_serial_number)
-                    in ch.external_ids.get(
+                    in utils.get_ovn_chassis_other_config(ch).get(
                         ovn_const.OVN_CMS_OPTIONS, '').split(',')):
                 return ch
         msg = _('Chassis with %s %s %s does not exist'
diff --git a/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovsdb_monitor.py b/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovsdb_monitor.py
index 21866b77983..ea74781c8df 100644
--- a/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovsdb_monitor.py
+++ b/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovsdb_monitor.py
@@ -172,12 +172,21 @@ def handle_ha_chassis_group_changes(self, event, row, old):
     def match_fn(self, event, row, old):
         if event != self.ROW_UPDATE:
             return True
-        # NOTE(lucasgomes): If the external_ids column wasn't updated
-        # (meaning, Chassis "gateway" status didn't change) just returns
-        if not hasattr(old, 'external_ids') and event == self.ROW_UPDATE:
+
+        # NOTE(ralonsoh): LP#1990229 to be removed when min OVN version is
+        # 22.09
+        other_config = ('other_config' if hasattr(row, 'other_config') else
+                        'external_ids')
+        # NOTE(lucasgomes): If the other_config/external_ids column wasn't
+        # updated (meaning, Chassis "gateway" status didn't change) just
+        # returns
+        if not hasattr(old, other_config) and event == self.ROW_UPDATE:
             return False
-        if (old.external_ids.get('ovn-bridge-mappings') !=
-                row.external_ids.get('ovn-bridge-mappings')):
+        old_br_mappings = utils.get_ovn_chassis_other_config(old).get(
+            'ovn-bridge-mappings')
+        new_br_mappings = utils.get_ovn_chassis_other_config(row).get(
+            'ovn-bridge-mappings')
+        if old_br_mappings != new_br_mappings:
             return True
         # Check if either the Gateway status or Availability Zones has
         # changed in the Chassis
@@ -192,8 +201,9 @@ def match_fn(self, event, row, old):
     def run(self, event, row, old):
         host = row.hostname
         phy_nets = []
+        new_other_config = utils.get_ovn_chassis_other_config(row)
         if event != self.ROW_DELETE:
-            bridge_mappings = row.external_ids.get('ovn-bridge-mappings', '')
+            bridge_mappings = new_other_config.get('ovn-bridge-mappings', '')
             mapping_dict = helpers.parse_mappings(bridge_mappings.split(','))
             phy_nets = list(mapping_dict)
 
@@ -208,9 +218,10 @@ def run(self, event, row, old):
             if event == self.ROW_DELETE:
                 kwargs['event_from_chassis'] = row.name
             elif event == self.ROW_UPDATE:
-                old_mappings = old.external_ids.get('ovn-bridge-mappings',
+                old_other_config = utils.get_ovn_chassis_other_config(old)
+                old_mappings = old_other_config.get('ovn-bridge-mappings',
                                                     set()) or set()
-                new_mappings = row.external_ids.get('ovn-bridge-mappings',
+                new_mappings = new_other_config.get('ovn-bridge-mappings',
                                                     set()) or set()
                 if old_mappings:
                     old_mappings = set(old_mappings.split(','))
@@ -339,11 +350,17 @@ class ChassisAgentTypeChangeEvent(ChassisEvent):
     events = (BaseEvent.ROW_UPDATE,)
 
     def match_fn(self, event, row, old=None):
-        if not getattr(old, 'external_ids', False):
+        # NOTE(ralonsoh): LP#1990229 to be removed when min OVN version is
+        # 22.09
+        other_config = ('other_config' if hasattr(row, 'other_config') else
+                        'external_ids')
+        if not getattr(old, other_config, False):
             return False
-        agent_type_change = n_agent.NeutronAgent.chassis_from_private(
-                row).external_ids.get('ovn-cms-options', []) != (
-                        old.external_ids.get('ovn-cms-options', []))
+        chassis = n_agent.NeutronAgent.chassis_from_private(row)
+        new_other_config = utils.get_ovn_chassis_other_config(chassis)
+        old_other_config = utils.get_ovn_chassis_other_config(old)
+        agent_type_change = new_other_config.get('ovn-cms-options', []) != (
+            old_other_config.get('ovn-cms-options', []))
         return agent_type_change
 
     def run(self, event, row, old):
diff --git a/neutron/tests/base.py b/neutron/tests/base.py
index 14aa07a77ff..6f8bf486594 100644
--- a/neutron/tests/base.py
+++ b/neutron/tests/base.py
@@ -492,7 +492,11 @@ def setup_rootwrap(self):
                     root_helper_daemon=get_rootwrap_daemon_cmd())
 
     def _simulate_concurrent_requests_process_and_raise(self, calls, args):
+        self._simulate_concurrent_requests_process(calls, args,
+                                                   raise_on_exception=True)
 
+    def _simulate_concurrent_requests_process(self, calls, args,
+                                              raise_on_exception=False):
         class SimpleThread(threading.Thread):
             def __init__(self, q):
                 super(SimpleThread, self).__init__()
@@ -529,10 +533,16 @@ def get_exception(self):
             t.start()
         q.join()
 
+        threads_exceptions = []
         for t in threads:
             e = t.get_exception()
             if e:
-                raise e
+                if raise_on_exception:
+                    raise e
+                else:
+                    threads_exceptions.append(e)
+
+        return threads_exceptions
 
 
 class PluginFixture(fixtures.Fixture):
diff --git a/neutron/tests/fullstack/test_l3_agent.py b/neutron/tests/fullstack/test_l3_agent.py
index 84603266dc5..1a39efa844b 100644
--- a/neutron/tests/fullstack/test_l3_agent.py
+++ b/neutron/tests/fullstack/test_l3_agent.py
@@ -270,25 +270,37 @@ def _is_filter_set(direction):
     def _test_concurrent_router_subnet_attachment_overlapping_cidr(self,
                                                                    ha=False):
         tenant_id = uuidutils.generate_uuid()
-        subnet_cidr = '10.100.0.0/24'
-        network1 = self.safe_client.create_network(
-            tenant_id, name='foo-network1')
-        subnet1 = self.safe_client.create_subnet(
-            tenant_id, network1['id'], subnet_cidr)
-        network2 = self.safe_client.create_network(
-            tenant_id, name='foo-network2')
-        subnet2 = self.safe_client.create_subnet(
-            tenant_id, network2['id'], subnet_cidr)
+        subnet_cidr = '10.200.0.0/24'
+        # to have many port interactions where race conditions would happen
+        # deleting ports meanwhile find operations to evaluate the overlapping
+        subnets = 10
+
+        funcs = []
+        args = []
         router = self.safe_client.create_router(tenant_id, ha=ha)
 
-        funcs = [self.safe_client.add_router_interface,
-                 self.safe_client.add_router_interface]
-        args = [(router['id'], subnet1['id']), (router['id'], subnet2['id'])]
-        self.assertRaises(
-            exceptions.BadRequest,
-            self._simulate_concurrent_requests_process_and_raise,
-            funcs,
-            args)
+        for i in range(subnets):
+            network_tmp = self.safe_client.create_network(
+                tenant_id, name='foo-network' + str(i))
+            subnet_tmp = self.safe_client.create_subnet(
+                tenant_id, network_tmp['id'], subnet_cidr)
+            funcs.append(self.safe_client.add_router_interface)
+            args.append((router['id'], subnet_tmp['id']))
+
+        exception_requests = self._simulate_concurrent_requests_process(
+            funcs, args)
+
+        if not all(type(e) == exceptions.BadRequest
+                   for e in exception_requests):
+            self.fail('Unexpected exception adding interfaces to router from '
+                      'different subnets overlapping')
+
+        if not len(exception_requests) >= (subnets - 1):
+            self.fail('If we have tried to associate %s subnets overlapping '
+                      'cidr to the router, we should have received at least '
+                      '%s or %s rejected requests, but we have only received '
+                      '%s', (str(subnets), str(subnets - 1), str(subnets),
+                             str(len(exception_requests))))
 
 
 class TestLegacyL3Agent(TestL3Agent):
@@ -441,7 +453,7 @@ def test_external_subnet_changed(self):
     def test_router_fip_qos_after_admin_state_down_up(self):
         self._router_fip_qos_after_admin_state_down_up()
 
-    def test_concurrent_router_subnet_attachment_overlapping_cidr_(self):
+    def test_concurrent_router_subnet_attachment_overlapping_cidr(self):
         self._test_concurrent_router_subnet_attachment_overlapping_cidr()
 
 
@@ -601,6 +613,6 @@ def test_external_subnet_changed(self):
     def test_router_fip_qos_after_admin_state_down_up(self):
         self._router_fip_qos_after_admin_state_down_up(ha=True)
 
-    def test_concurrent_router_subnet_attachment_overlapping_cidr_(self):
+    def test_concurrent_router_subnet_attachment_overlapping_cidr(self):
         self._test_concurrent_router_subnet_attachment_overlapping_cidr(
             ha=True)
diff --git a/neutron/tests/functional/agent/l3/framework.py b/neutron/tests/functional/agent/l3/framework.py
index c773d2945f3..45de9ac8278 100644
--- a/neutron/tests/functional/agent/l3/framework.py
+++ b/neutron/tests/functional/agent/l3/framework.py
@@ -79,11 +79,11 @@
         %(int_port_ipv6)s dev %(internal_device_name)s scope link no_track
     }
     virtual_routes {
-        0.0.0.0/0 via %(default_gateway_ip)s dev %(ex_device_name)s no_track
-        8.8.8.0/24 via 19.4.4.4 no_track
-        %(extra_subnet_cidr)s dev %(ex_device_name)s scope link no_track
+        0.0.0.0/0 via %(default_gateway_ip)s dev %(ex_device_name)s no_track protocol static
+        8.8.8.0/24 via 19.4.4.4 no_track protocol static
+        %(extra_subnet_cidr)s dev %(ex_device_name)s scope link no_track protocol static
     }
-}"""
+}"""  # noqa: E501 # pylint: disable=line-too-long
 
 
 def get_ovs_bridge(br_name):
diff --git a/neutron/tests/functional/base.py b/neutron/tests/functional/base.py
index ade4c7af93e..66019db34a2 100644
--- a/neutron/tests/functional/base.py
+++ b/neutron/tests/functional/base.py
@@ -423,7 +423,8 @@ def restart(self):
         self._start_ovn_northd()
 
     def add_fake_chassis(self, host, physical_nets=None, external_ids=None,
-                         name=None, enable_chassis_as_gw=False):
+                         name=None, enable_chassis_as_gw=False,
+                         other_config=None):
         def append_cms_options(ext_ids, value):
             if 'ovn-cms-options' not in ext_ids:
                 ext_ids['ovn-cms-options'] = value
@@ -432,14 +433,15 @@ def append_cms_options(ext_ids, value):
 
         physical_nets = physical_nets or []
         external_ids = external_ids or {}
+        other_config = other_config or {}
         if enable_chassis_as_gw:
-            append_cms_options(external_ids, 'enable-chassis-as-gw')
+            append_cms_options(other_config, 'enable-chassis-as-gw')
 
         bridge_mapping = ",".join(["%s:br-provider%s" % (phys_net, i)
                                   for i, phys_net in enumerate(physical_nets)])
         if name is None:
             name = uuidutils.generate_uuid()
-        external_ids['ovn-bridge-mappings'] = bridge_mapping
+        other_config['ovn-bridge-mappings'] = bridge_mapping
         # We'll be using different IP addresses every time for the Encap of
         # the fake chassis as the SB schema doesn't allow to have two entries
         # with same (ip,type) pairs as of OVS 2.11. This shouldn't have any
@@ -450,7 +452,8 @@ def append_cms_options(ext_ids, value):
         self._counter += 1
         chassis = self.sb_api.chassis_add(
             name, ['geneve'], '172.24.4.%d' % self._counter,
-            external_ids=external_ids, hostname=host).execute(check_error=True)
+            external_ids=external_ids, hostname=host,
+            other_config=other_config).execute(check_error=True)
         if self.sb_api.is_table_present('Chassis_Private'):
             nb_cfg_timestamp = timeutils.utcnow_ts() * 1000
             self.sb_api.db_create(
diff --git a/neutron/tests/functional/plugins/ml2/drivers/ovn/mech_driver/ovsdb/extensions/test_placement.py b/neutron/tests/functional/plugins/ml2/drivers/ovn/mech_driver/ovsdb/extensions/test_placement.py
index 5e808fe7eaf..327718d7c93 100644
--- a/neutron/tests/functional/plugins/ml2/drivers/ovn/mech_driver/ovsdb/extensions/test_placement.py
+++ b/neutron/tests/functional/plugins/ml2/drivers/ovn/mech_driver/ovsdb/extensions/test_placement.py
@@ -72,7 +72,7 @@ def setUp(self, maintenance_worker=False, service_plugins=None):
         self.mock_send_batch = mock.patch.object(
             placement_extension, '_send_deferred_batch').start()
 
-    def _build_external_ids(self, bandwidths, inventory_defaults, hypervisors):
+    def _build_other_config(self, bandwidths, inventory_defaults, hypervisors):
         options = []
         if bandwidths:
             options.append(n_const.RP_BANDWIDTHS + '=' + bandwidths)
@@ -85,17 +85,17 @@ def _build_external_ids(self, bandwidths, inventory_defaults, hypervisors):
 
     def _create_chassis(self, host, name, physical_nets=None, bandwidths=None,
                         inventory_defaults=None, hypervisors=None):
-        external_ids = self._build_external_ids(bandwidths, inventory_defaults,
+        other_config = self._build_other_config(bandwidths, inventory_defaults,
                                                 hypervisors)
         self.add_fake_chassis(host, physical_nets=physical_nets,
-                              external_ids=external_ids, name=name)
+                              other_config=other_config, name=name)
 
     def _update_chassis(self, name, bandwidths=None, inventory_defaults=None,
                         hypervisors=None):
-        external_ids = self._build_external_ids(bandwidths, inventory_defaults,
+        other_config = self._build_other_config(bandwidths, inventory_defaults,
                                                 hypervisors)
         self.sb_api.db_set(
-            'Chassis', name, ('external_ids', external_ids)
+            'Chassis', name, ('other_config', other_config)
         ).execute(check_error=True)
 
     def _check_placement_config(self, expected_chassis):
diff --git a/neutron/tests/functional/plugins/ml2/drivers/ovn/mech_driver/ovsdb/test_impl_idl.py b/neutron/tests/functional/plugins/ml2/drivers/ovn/mech_driver/ovsdb/test_impl_idl.py
index d139385ea34..4c5b0be23f1 100644
--- a/neutron/tests/functional/plugins/ml2/drivers/ovn/mech_driver/ovsdb/test_impl_idl.py
+++ b/neutron/tests/functional/plugins/ml2/drivers/ovn/mech_driver/ovsdb/test_impl_idl.py
@@ -52,11 +52,11 @@ def setUp(self):
         super(TestSbApi, self).setUp()
         self.data = {
             'chassis': [
-                {'external_ids': {'ovn-bridge-mappings':
+                {'other_config': {'ovn-bridge-mappings':
                                   'public:br-ex,private:br-0'}},
-                {'external_ids': {'ovn-bridge-mappings':
+                {'other_config': {'ovn-bridge-mappings':
                                   'public:br-ex,public2:br-ex2'}},
-                {'external_ids': {'ovn-bridge-mappings':
+                {'other_config': {'ovn-bridge-mappings':
                                   'public:br-ex'}},
             ]
         }
@@ -70,7 +70,7 @@ def load_test_data(self):
                 txn.add(self.api.chassis_add(
                     chassis['name'], ['geneve'], chassis['hostname'],
                     hostname=chassis['hostname'],
-                    external_ids=chassis['external_ids']))
+                    other_config=chassis['other_config']))
 
     def test_get_chassis_hostname_and_physnets(self):
         mapping = self.api.get_chassis_hostname_and_physnets()
@@ -97,7 +97,7 @@ def test_get_chassis_and_physnets(self):
     def test_multiple_physnets_in_one_bridge(self):
         self.data = {
             'chassis': [
-                {'external_ids': {'ovn-bridge-mappings': 'p1:br-ex,p2:br-ex'}}
+                {'other_config': {'ovn-bridge-mappings': 'p1:br-ex,p2:br-ex'}}
             ]
         }
         self.load_test_data()
diff --git a/neutron/tests/functional/plugins/ml2/drivers/ovn/mech_driver/ovsdb/test_ovsdb_monitor.py b/neutron/tests/functional/plugins/ml2/drivers/ovn/mech_driver/ovsdb/test_ovsdb_monitor.py
index 71e4eda29f9..d63d54ca749 100644
--- a/neutron/tests/functional/plugins/ml2/drivers/ovn/mech_driver/ovsdb/test_ovsdb_monitor.py
+++ b/neutron/tests/functional/plugins/ml2/drivers/ovn/mech_driver/ovsdb/test_ovsdb_monitor.py
@@ -437,9 +437,8 @@ def setUp(self):
             chassis_name, self.mech_driver.agent_chassis_table)
         self.mech_driver.sb_ovn.idl.notify_handler.watch_event(row_event)
         self.chassis_name = self.add_fake_chassis(
-            self.FAKE_CHASSIS_HOST,
-            external_ids={'ovn-cms-options': 'enable-chassis-as-gw'},
-            name=chassis_name)
+            self.FAKE_CHASSIS_HOST, name=chassis_name,
+            enable_chassis_as_gw=True)
         self.assertTrue(row_event.wait())
         n_utils.wait_until_true(
             lambda: len(list(neutron_agent.AgentCache())) == 1)
@@ -447,11 +446,11 @@ def setUp(self):
     def test_agent_change_controller(self):
         self.assertEqual(neutron_agent.ControllerGatewayAgent,
                 type(neutron_agent.AgentCache()[self.chassis_name]))
-        self.sb_api.db_set('Chassis', self.chassis_name, ('external_ids',
+        self.sb_api.db_set('Chassis', self.chassis_name, ('other_config',
                 {'ovn-cms-options': ''})).execute(check_error=True)
         n_utils.wait_until_true(lambda:
                 neutron_agent.AgentCache()[self.chassis_name].
-                chassis.external_ids['ovn-cms-options'] == '')
+                chassis.other_config['ovn-cms-options'] == '')
         self.assertEqual(neutron_agent.ControllerAgent,
                 type(neutron_agent.AgentCache()[self.chassis_name]))
 
diff --git a/neutron/tests/functional/plugins/ml2/drivers/ovn/mech_driver/test_mech_driver.py b/neutron/tests/functional/plugins/ml2/drivers/ovn/mech_driver/test_mech_driver.py
index 88e8e3c37ac..e3de3b5e3b4 100644
--- a/neutron/tests/functional/plugins/ml2/drivers/ovn/mech_driver/test_mech_driver.py
+++ b/neutron/tests/functional/plugins/ml2/drivers/ovn/mech_driver/test_mech_driver.py
@@ -66,16 +66,16 @@ def setUp(self):
         self.add_fake_chassis(self.ovs_host)
         self.add_fake_chassis(
             self.dpdk_host,
-            external_ids={'datapath-type': 'netdev',
+            other_config={'datapath-type': 'netdev',
                           'iface-types': 'dummy,dummy-internal,dpdkvhostuser'})
 
         self.add_fake_chassis(
             self.invalid_dpdk_host,
-            external_ids={'datapath-type': 'netdev',
+            other_config={'datapath-type': 'netdev',
                           'iface-types': 'dummy,dummy-internal,geneve,vxlan'})
         self.add_fake_chassis(
             self.smartnic_dpu_host,
-            external_ids={ovn_const.OVN_CMS_OPTIONS: '{}={}'.format(
+            other_config={ovn_const.OVN_CMS_OPTIONS: '{}={}'.format(
                 ovn_const.CMS_OPT_CARD_SERIAL_NUMBER,
                 self.smartnic_dpu_serial)})
         self.n1 = self._make_network(self.fmt, 'n1', True)
diff --git a/neutron/tests/functional/services/ovn_l3/test_plugin.py b/neutron/tests/functional/services/ovn_l3/test_plugin.py
index be7fb6c3aef..c7e9fd7445d 100644
--- a/neutron/tests/functional/services/ovn_l3/test_plugin.py
+++ b/neutron/tests/functional/services/ovn_l3/test_plugin.py
@@ -131,7 +131,7 @@ def test_gateway_chassis_with_cms_and_bridge_mappings(self):
         # Test if chassis3 is selected as candidate or not.
         self.chassis3 = self.add_fake_chassis(
             'ovs-host3', physical_nets=['physnet1'],
-            external_ids={'ovn-cms-options': 'enable-chassis-as-gw'})
+            other_config={'ovn-cms-options': 'enable-chassis-as-gw'})
         self._check_gateway_chassis_candidates([self.chassis3])
 
     def test_gateway_chassis_with_cms_and_no_bridge_mappings(self):
@@ -139,7 +139,7 @@ def test_gateway_chassis_with_cms_and_no_bridge_mappings(self):
         # chassis3 is having enable-chassis-as-gw, but no bridge mappings.
         self.chassis3 = self.add_fake_chassis(
             'ovs-host3',
-            external_ids={'ovn-cms-options': 'enable-chassis-as-gw'})
+            other_config={'ovn-cms-options': 'enable-chassis-as-gw'})
         ovn_client = self.l3_plugin._ovn_client
         ext1 = self._create_ext_network(
             'ext1', 'vlan', 'physnet1', 1, "10.0.0.1", "10.0.0.0/24")
@@ -484,7 +484,7 @@ def _get_result_dict():
             self.skipTest('L3 HA not supported')
         ovn_client = self.l3_plugin._ovn_client
         chassis4 = self.add_fake_chassis(
-            'ovs-host4', physical_nets=['physnet4'], external_ids={
+            'ovs-host4', physical_nets=['physnet4'], other_config={
                 'ovn-cms-options': 'enable-chassis-as-gw'})
         ovn_client._ovn_scheduler = l3_sched.OVNGatewayLeastLoadedScheduler()
         ext1 = self._create_ext_network(
@@ -516,7 +516,7 @@ def _get_result_dict():
 
         # Add another chassis as a gateway chassis
         chassis5 = self.add_fake_chassis(
-            'ovs-host5', physical_nets=['physnet4'], external_ids={
+            'ovs-host5', physical_nets=['physnet4'], other_config={
                 'ovn-cms-options': 'enable-chassis-as-gw'})
         # Add a node as compute node. Compute node wont be
         # used to schedule the router gateway ports therefore
@@ -546,8 +546,7 @@ def test_gateway_chassis_rebalance_max_chassis(self):
             chassis_list.append(
                 self.add_fake_chassis(
                     'ovs-host%s' % i, physical_nets=['physnet1'],
-                    external_ids={
-                        'ovn-cms-options': 'enable-chassis-as-gw'}))
+                    other_config={'ovn-cms-options': 'enable-chassis-as-gw'}))
 
         ext1 = self._create_ext_network(
             'ext1', 'vlan', 'physnet1', 1, "10.0.0.1", "10.0.0.0/24")
diff --git a/neutron/tests/unit/agent/linux/test_keepalived.py b/neutron/tests/unit/agent/linux/test_keepalived.py
index 28474f9dc89..169f075ff95 100644
--- a/neutron/tests/unit/agent/linux/test_keepalived.py
+++ b/neutron/tests/unit/agent/linux/test_keepalived.py
@@ -164,7 +164,7 @@ class KeepalivedConfTestCase(KeepalivedBaseTestCase,
                 192.168.55.0/24 dev eth10 no_track
             }
             virtual_routes {
-                0.0.0.0/0 via 192.168.1.1 dev eth1 no_track
+                0.0.0.0/0 via 192.168.1.1 dev eth1 no_track protocol static
             }
         }
         vrrp_instance VR_2 {
@@ -247,7 +247,7 @@ class KeepalivedConfWithoutNoTrackTestCase(KeepalivedConfTestCase):
                 192.168.55.0/24 dev eth10
             }
             virtual_routes {
-                0.0.0.0/0 via 192.168.1.1 dev eth1
+                0.0.0.0/0 via 192.168.1.1 dev eth1 protocol static
             }
         }
         vrrp_instance VR_2 {
@@ -323,11 +323,11 @@ def test_remove_routes_on_interface(self):
 
     def test_build_config(self):
         expected = """    virtual_routes {
-        0.0.0.0/0 via 1.0.0.254 dev eth0 no_track
-        ::/0 via fe80::3e97:eff:fe26:3bfa/64 dev eth1 no_track
-        10.0.0.0/8 via 1.0.0.1 no_track
-        20.0.0.0/8 via 2.0.0.2 no_track
-        30.0.0.0/8 dev eth0 scope link no_track
+        0.0.0.0/0 via 1.0.0.254 dev eth0 no_track protocol static
+        ::/0 via fe80::3e97:eff:fe26:3bfa/64 dev eth1 no_track protocol static
+        10.0.0.0/8 via 1.0.0.1 no_track protocol static
+        20.0.0.0/8 via 2.0.0.2 no_track protocol static
+        30.0.0.0/8 dev eth0 scope link no_track protocol static
     }"""
         with mock.patch.object(
                 keepalived, '_is_keepalived_use_no_track_supported',
@@ -337,11 +337,11 @@ def test_build_config(self):
 
     def _get_no_track_less_expected_config(self):
         expected = """    virtual_routes {
-        0.0.0.0/0 via 1.0.0.254 dev eth0
-        ::/0 via fe80::3e97:eff:fe26:3bfa/64 dev eth1
-        10.0.0.0/8 via 1.0.0.1
-        20.0.0.0/8 via 2.0.0.2
-        30.0.0.0/8 dev eth0 scope link
+        0.0.0.0/0 via 1.0.0.254 dev eth0 protocol static
+        ::/0 via fe80::3e97:eff:fe26:3bfa/64 dev eth1 protocol static
+        10.0.0.0/8 via 1.0.0.1 protocol static
+        20.0.0.0/8 via 2.0.0.2 protocol static
+        30.0.0.0/8 dev eth0 scope link protocol static
     }"""
         return expected
 
@@ -395,7 +395,7 @@ def _test_remove_addresses_by_interface(self, no_track_value):
                     192.168.1.0/24 dev eth1%(no_track)s
                 }
                 virtual_routes {
-                    0.0.0.0/0 via 192.168.1.1 dev eth1%(no_track)s
+                    0.0.0.0/0 via 192.168.1.1 dev eth1%(no_track)s protocol static
                 }
             }
             vrrp_instance VR_2 {
@@ -416,7 +416,7 @@ def _test_remove_addresses_by_interface(self, no_track_value):
                     192.168.3.0/24 dev eth6%(no_track)s
                     192.168.55.0/24 dev eth10%(no_track)s
                 }
-            }""" % {'no_track': no_track_value})
+            }""" % {'no_track': no_track_value})  # noqa: E501 # pylint: disable=line-too-long
 
         self.assertEqual(expected, config.get_config_str())
 
@@ -501,8 +501,9 @@ def test_virtual_route_with_dev(self):
                 return_value=True):
             route = keepalived.KeepalivedVirtualRoute(
                 n_consts.IPv4_ANY, '1.2.3.4', 'eth0')
-            self.assertEqual('0.0.0.0/0 via 1.2.3.4 dev eth0 no_track',
-                             route.build_config())
+            self.assertEqual(
+                '0.0.0.0/0 via 1.2.3.4 dev eth0 no_track protocol static',
+                route.build_config())
 
     def test_virtual_route_with_dev_no_track_not_supported(self):
         with mock.patch.object(
@@ -510,14 +511,14 @@ def test_virtual_route_with_dev_no_track_not_supported(self):
                 return_value=False):
             route = keepalived.KeepalivedVirtualRoute(
                 n_consts.IPv4_ANY, '1.2.3.4', 'eth0')
-            self.assertEqual('0.0.0.0/0 via 1.2.3.4 dev eth0',
+            self.assertEqual('0.0.0.0/0 via 1.2.3.4 dev eth0 protocol static',
                              route.build_config())
 
     def test_virtual_route_with_dev_without_no_track(self):
         cfg.CONF.set_override('keepalived_use_no_track', False)
         route = keepalived.KeepalivedVirtualRoute(n_consts.IPv4_ANY, '1.2.3.4',
                                                   'eth0')
-        self.assertEqual('0.0.0.0/0 via 1.2.3.4 dev eth0',
+        self.assertEqual('0.0.0.0/0 via 1.2.3.4 dev eth0 protocol static',
                          route.build_config())
 
     def test_virtual_route_without_dev(self):
@@ -525,7 +526,7 @@ def test_virtual_route_without_dev(self):
                 keepalived, '_is_keepalived_use_no_track_supported',
                 return_value=True):
             route = keepalived.KeepalivedVirtualRoute('50.0.0.0/8', '1.2.3.4')
-            self.assertEqual('50.0.0.0/8 via 1.2.3.4 no_track',
+            self.assertEqual('50.0.0.0/8 via 1.2.3.4 no_track protocol static',
                              route.build_config())
 
     def test_virtual_route_without_dev_no_track_not_supported(self):
@@ -533,13 +534,14 @@ def test_virtual_route_without_dev_no_track_not_supported(self):
                 keepalived, '_is_keepalived_use_no_track_supported',
                 return_value=False):
             route = keepalived.KeepalivedVirtualRoute('50.0.0.0/8', '1.2.3.4')
-            self.assertEqual('50.0.0.0/8 via 1.2.3.4',
+            self.assertEqual('50.0.0.0/8 via 1.2.3.4 protocol static',
                              route.build_config())
 
     def test_virtual_route_without_dev_without_no_track(self):
         cfg.CONF.set_override('keepalived_use_no_track', False)
         route = keepalived.KeepalivedVirtualRoute('50.0.0.0/8', '1.2.3.4')
-        self.assertEqual('50.0.0.0/8 via 1.2.3.4', route.build_config())
+        self.assertEqual('50.0.0.0/8 via 1.2.3.4 protocol static',
+                         route.build_config())
 
 
 class KeepalivedTrackScriptTestCase(KeepalivedBaseTestCase):
diff --git a/neutron/tests/unit/common/ovn/test_utils.py b/neutron/tests/unit/common/ovn/test_utils.py
index a12874a9a18..c6960a88d36 100644
--- a/neutron/tests/unit/common/ovn/test_utils.py
+++ b/neutron/tests/unit/common/ovn/test_utils.py
@@ -62,33 +62,31 @@ def test_get_system_dns_resolvers(self):
 
     def test_is_gateway_chassis(self):
         chassis = fakes.FakeOvsdbRow.create_one_ovsdb_row(attrs={
-            'external_ids': {'ovn-cms-options': 'enable-chassis-as-gw'}})
+            'other_config': {'ovn-cms-options': 'enable-chassis-as-gw'}})
         non_gw_chassis_0 = fakes.FakeOvsdbRow.create_one_ovsdb_row(attrs={
-            'external_ids': {'ovn-cms-options': ''}})
-        non_gw_chassis_1 = fakes.FakeOvsdbRow.create_one_ovsdb_row(attrs={})
-        non_gw_chassis_2 = fakes.FakeOvsdbRow.create_one_ovsdb_row(attrs={
-            'external_ids': {}})
+            'other_config': {'ovn-cms-options': ''}})
+        non_gw_chassis_1 = fakes.FakeOvsdbRow.create_one_ovsdb_row(attrs={
+            'other_config': {}})
 
         self.assertTrue(utils.is_gateway_chassis(chassis))
         self.assertFalse(utils.is_gateway_chassis(non_gw_chassis_0))
         self.assertFalse(utils.is_gateway_chassis(non_gw_chassis_1))
-        self.assertFalse(utils.is_gateway_chassis(non_gw_chassis_2))
 
     def test_get_chassis_availability_zones_no_azs(self):
         chassis = fakes.FakeOvsdbRow.create_one_ovsdb_row(attrs={
-            'external_ids': {'ovn-cms-options': 'enable-chassis-as-gw'}})
+            'other_config': {'ovn-cms-options': 'enable-chassis-as-gw'}})
         self.assertEqual(set(), utils.get_chassis_availability_zones(chassis))
 
     def test_get_chassis_availability_zones_one_az(self):
         chassis = fakes.FakeOvsdbRow.create_one_ovsdb_row(attrs={
-            'external_ids': {'ovn-cms-options':
+            'other_config': {'ovn-cms-options':
                              'enable-chassis-as-gw,availability-zones=az0'}})
         self.assertEqual(
             {'az0'}, utils.get_chassis_availability_zones(chassis))
 
     def test_get_chassis_availability_zones_multiple_az(self):
         chassis = fakes.FakeOvsdbRow.create_one_ovsdb_row(attrs={
-            'external_ids': {
+            'other_config': {
                 'ovn-cms-options':
                 'enable-chassis-as-gw,availability-zones=az0:az1 :az2:: :'}})
         self.assertEqual(
@@ -97,7 +95,7 @@ def test_get_chassis_availability_zones_multiple_az(self):
 
     def test_get_chassis_availability_zones_malformed(self):
         chassis = fakes.FakeOvsdbRow.create_one_ovsdb_row(attrs={
-            'external_ids': {'ovn-cms-options':
+            'other_config': {'ovn-cms-options':
                              'enable-chassis-as-gw,availability-zones:az0'}})
         self.assertEqual(
             set(), utils.get_chassis_availability_zones(chassis))
@@ -156,16 +154,16 @@ def test_parse_ovn_lb_port_forwarding(self):
     def test_get_chassis_in_azs(self):
         ch0 = fakes.FakeOvsdbRow.create_one_ovsdb_row(attrs={
             'name': 'ch0',
-            'external_ids': {
+            'other_config': {
                 'ovn-cms-options':
                 'enable-chassis-as-gw,availability-zones=az0:az1:az2'}})
         ch1 = fakes.FakeOvsdbRow.create_one_ovsdb_row(attrs={
             'name': 'ch1',
-            'external_ids': {
+            'other_config': {
                 'ovn-cms-options': 'enable-chassis-as-gw'}})
         ch2 = fakes.FakeOvsdbRow.create_one_ovsdb_row(attrs={
             'name': 'ch2',
-            'external_ids': {
+            'other_config': {
                 'ovn-cms-options':
                 'enable-chassis-as-gw,availability-zones=az1:az5'}})
 
@@ -183,21 +181,21 @@ def test_get_chassis_in_azs(self):
     def test_get_gateway_chassis_without_azs(self):
         ch0 = fakes.FakeOvsdbRow.create_one_ovsdb_row(attrs={
             'name': 'ch0',
-            'external_ids': {
+            'other_config': {
                 'ovn-cms-options':
                 'enable-chassis-as-gw,availability-zones=az0:az1:az2'}})
         ch1 = fakes.FakeOvsdbRow.create_one_ovsdb_row(attrs={
             'name': 'ch1',
-            'external_ids': {
+            'other_config': {
                 'ovn-cms-options': 'enable-chassis-as-gw'}})
         ch2 = fakes.FakeOvsdbRow.create_one_ovsdb_row(attrs={
             'name': 'ch2',
-            'external_ids': {
+            'other_config': {
                 'ovn-cms-options':
                 'enable-chassis-as-gw,availability-zones=az1:az5'}})
         ch3 = fakes.FakeOvsdbRow.create_one_ovsdb_row(attrs={
             'name': 'ch3',
-            'external_ids': {}})
+            'other_config': {}})
 
         chassis_list = [ch0, ch1, ch2, ch3]
         self.assertEqual(
diff --git a/neutron/tests/unit/fake_resources.py b/neutron/tests/unit/fake_resources.py
index 984600735ac..9228f161325 100644
--- a/neutron/tests/unit/fake_resources.py
+++ b/neutron/tests/unit/fake_resources.py
@@ -868,20 +868,23 @@ def create(attrs=None, az_list=None, chassis_as_gw=False,
             cms_opts.append('%s=%s' % (ovn_const.CMS_OPT_CARD_SERIAL_NUMBER,
                                        card_serial_number))
 
-        external_ids = {}
+        # NOTE(ralonsoh): LP#1990229, once min OVN version >= 20.06, the CMS
+        # options and the bridge mappings should be stored only in
+        # "other_config".
+        other_config = {}
         if cms_opts:
-            external_ids[ovn_const.OVN_CMS_OPTIONS] = ','.join(cms_opts)
+            other_config[ovn_const.OVN_CMS_OPTIONS] = ','.join(cms_opts)
 
         if bridge_mappings:
-            external_ids['ovn-bridge-mappings'] = ','.join(bridge_mappings)
+            other_config['ovn-bridge-mappings'] = ','.join(bridge_mappings)
 
         chassis_attrs = {
             'encaps': [],
-            'external_ids': external_ids,
+            'external_ids': '',
             'hostname': '',
             'name': uuidutils.generate_uuid(),
             'nb_cfg': 0,
-            'other_config': {},
+            'other_config': other_config,
             'transport_zones': [],
             'vtep_logical_switches': []}
 
diff --git a/neutron/tests/unit/plugins/ml2/drivers/ovn/agent/test_neutron_agent.py b/neutron/tests/unit/plugins/ml2/drivers/ovn/agent/test_neutron_agent.py
index ed434cab186..cd92c937534 100644
--- a/neutron/tests/unit/plugins/ml2/drivers/ovn/agent/test_neutron_agent.py
+++ b/neutron/tests/unit/plugins/ml2/drivers/ovn/agent/test_neutron_agent.py
@@ -31,7 +31,7 @@ def setUp(self):
         self.names_ref = []
         for i in range(10):  # Add 10 agents.
             chassis_private = fakes.FakeOvsdbRow.create_one_ovsdb_row(
-                attrs={'name': 'chassis' + str(i)})
+                attrs={'name': 'chassis' + str(i), 'other_config': {}})
             self.agent_cache.update(ovn_const.OVN_CONTROLLER_AGENT,
                                     chassis_private)
             self.names_ref.append('chassis' + str(i))
diff --git a/neutron/tests/unit/plugins/ml2/drivers/ovn/mech_driver/ovsdb/test_impl_idl_ovn.py b/neutron/tests/unit/plugins/ml2/drivers/ovn/mech_driver/ovsdb/test_impl_idl_ovn.py
index 8dba2de7be8..1ea2572d6e0 100644
--- a/neutron/tests/unit/plugins/ml2/drivers/ovn/mech_driver/ovsdb/test_impl_idl_ovn.py
+++ b/neutron/tests/unit/plugins/ml2/drivers/ovn/mech_driver/ovsdb/test_impl_idl_ovn.py
@@ -800,7 +800,7 @@ class TestSBImplIdlOvnBase(TestDBImplIdlOvn):
         'chassis': [
             {
                 'hostname': 'fake-smartnic-dpu-chassis.fqdn',
-                'external_ids': {
+                'other_config': {
                     ovn_const.OVN_CMS_OPTIONS: (
                         'firstoption,'
                         'card-serial-number=fake-serial,'
diff --git a/neutron/tests/unit/plugins/ml2/drivers/ovn/mech_driver/ovsdb/test_ovsdb_monitor.py b/neutron/tests/unit/plugins/ml2/drivers/ovn/mech_driver/ovsdb/test_ovsdb_monitor.py
index dda8cb33beb..c1d4279fcd4 100644
--- a/neutron/tests/unit/plugins/ml2/drivers/ovn/mech_driver/ovsdb/test_ovsdb_monitor.py
+++ b/neutron/tests/unit/plugins/ml2/drivers/ovn/mech_driver/ovsdb/test_ovsdb_monitor.py
@@ -81,6 +81,9 @@
                 "name": {"type": "string"},
                 "hostname": {"type": "string"},
                 "external_ids": {
+                    "type": {"key": "string", "value": "string",
+                             "min": 0, "max": "unlimited"}},
+                "other_config": {
                     "type": {"key": "string", "value": "string",
                              "min": 0, "max": "unlimited"}}},
             "isRoot": True,
@@ -520,7 +523,7 @@ def setUp(self):
         self.row_json = {
             "name": "fake-name",
             "hostname": "fake-hostname",
-            "external_ids": ['map', [["ovn-bridge-mappings",
+            "other_config": ['map', [["ovn-bridge-mappings",
                                       "fake-phynet1:fake-br1"]]]
         }
         self._mock_hash_ring = mock.patch.object(
@@ -544,14 +547,18 @@ def _test_chassis_helper(self, event, new_row_json, old_row_json=None):
         self.sb_idl.notify_handler.notify_loop()
 
     def test_chassis_create_event(self):
-        self._test_chassis_helper('create', self.row_json)
+        old_row_json = {'other_config': ['map', []]}
+        self._test_chassis_helper('create', self.row_json,
+                                  old_row_json=old_row_json)
         self.mech_driver.update_segment_host_mapping.assert_called_once_with(
             'fake-hostname', ['fake-phynet1'])
         self.l3_plugin.schedule_unhosted_gateways.assert_called_once_with(
             event_from_chassis=None)
 
     def test_chassis_delete_event(self):
-        self._test_chassis_helper('delete', self.row_json)
+        old_row_json = {'other_config': ['map', []]}
+        self._test_chassis_helper('delete', self.row_json,
+                                  old_row_json=old_row_json)
         self.mech_driver.update_segment_host_mapping.assert_called_once_with(
             'fake-hostname', [])
         self.l3_plugin.schedule_unhosted_gateways.assert_called_once_with(
@@ -559,7 +566,7 @@ def test_chassis_delete_event(self):
 
     def test_chassis_update_event(self):
         old_row_json = copy.deepcopy(self.row_json)
-        old_row_json['external_ids'][1][0][1] = (
+        old_row_json['other_config'][1][0][1] = (
             "fake-phynet2:fake-br2")
         self._test_chassis_helper('update', self.row_json, old_row_json)
         self.mech_driver.update_segment_host_mapping.assert_called_once_with(
@@ -568,9 +575,9 @@ def test_chassis_update_event(self):
             event_from_chassis=None)
 
     def test_chassis_update_event_reschedule_not_needed(self):
-        self.row_json['external_ids'][1].append(['foo_field', 'foo_value_new'])
+        self.row_json['other_config'][1].append(['foo_field', 'foo_value_new'])
         old_row_json = copy.deepcopy(self.row_json)
-        old_row_json['external_ids'][1][1][1] = (
+        old_row_json['other_config'][1][1][1] = (
             "foo_value")
         self._test_chassis_helper('update', self.row_json, old_row_json)
         self.mech_driver.update_segment_host_mapping.assert_not_called()
@@ -578,14 +585,14 @@ def test_chassis_update_event_reschedule_not_needed(self):
 
     def test_chassis_update_event_reschedule_lost_physnet(self):
         old_row_json = copy.deepcopy(self.row_json)
-        self.row_json['external_ids'][1][0][1] = ''
+        self.row_json['other_config'][1][0][1] = ''
         self._test_chassis_helper('update', self.row_json, old_row_json)
         self.l3_plugin.schedule_unhosted_gateways.assert_called_once_with(
             event_from_chassis='fake-name')
 
     def test_chassis_update_event_reschedule_add_physnet(self):
         old_row_json = copy.deepcopy(self.row_json)
-        self.row_json['external_ids'][1][0][1] += ',foo_physnet:foo_br'
+        self.row_json['other_config'][1][0][1] += ',foo_physnet:foo_br'
         self._test_chassis_helper('update', self.row_json, old_row_json)
         self.mech_driver.update_segment_host_mapping.assert_called_once_with(
             'fake-hostname', ['fake-phynet1', 'foo_physnet'])
@@ -594,7 +601,7 @@ def test_chassis_update_event_reschedule_add_physnet(self):
 
     def test_chassis_update_event_reschedule_add_and_remove_physnet(self):
         old_row_json = copy.deepcopy(self.row_json)
-        self.row_json['external_ids'][1][0][1] = 'foo_physnet:foo_br'
+        self.row_json['other_config'][1][0][1] = 'foo_physnet:foo_br'
         self._test_chassis_helper('update', self.row_json, old_row_json)
         self.mech_driver.update_segment_host_mapping.assert_called_once_with(
             'fake-hostname', ['foo_physnet'])
@@ -603,7 +610,7 @@ def test_chassis_update_event_reschedule_add_and_remove_physnet(self):
 
     def test_chassis_update_empty_no_external_ids(self):
         old_row_json = copy.deepcopy(self.row_json)
-        old_row_json.pop('external_ids')
+        old_row_json.pop('other_config')
         with mock.patch(
             'neutron.plugins.ml2.drivers.ovn.mech_driver.ovsdb.'
             'ovsdb_monitor.ChassisEvent.'
@@ -636,10 +643,10 @@ def test_handle_ha_chassis_group_changes_create_not_gw(self):
 
     def _test_handle_ha_chassis_group_changes_create(self, event):
         # Chassis
-        ext_ids = {
+        other_config = {
             'ovn-cms-options': 'enable-chassis-as-gw,availability-zones=az-0'}
         row = fakes.FakeOvsdbTable.create_one_ovsdb_table(
-            attrs={'name': 'SpongeBob', 'external_ids': ext_ids})
+            attrs={'name': 'SpongeBob', 'other_config': other_config})
         # HA Chassis
         ch0 = fakes.FakeOvsdbTable.create_one_ovsdb_table(
             attrs={'priority': 10})
@@ -671,10 +678,10 @@ def test_handle_ha_chassis_group_changes_create(self):
 
     def _test_handle_ha_chassis_group_changes_delete(self, event):
         # Chassis
-        ext_ids = {
+        other_config = {
             'ovn-cms-options': 'enable-chassis-as-gw,availability-zones=az-0'}
         row = fakes.FakeOvsdbTable.create_one_ovsdb_table(
-            attrs={'name': 'SpongeBob', 'external_ids': ext_ids})
+            attrs={'name': 'SpongeBob', 'other_config': other_config})
         # HA Chassis
         ha_ch = fakes.FakeOvsdbTable.create_one_ovsdb_table(
             attrs={'priority': 10})
@@ -698,10 +705,10 @@ def test_handle_ha_chassis_group_changes_delete(self):
     def test_handle_ha_chassis_group_changes_update_no_changes(self):
         # Assert nothing was done because the update didn't
         # change the gateway chassis status or the availability zones
-        ext_ids = {
+        other_config = {
             'ovn-cms-options': 'enable-chassis-as-gw,availability-zones=az-0'}
         new = fakes.FakeOvsdbTable.create_one_ovsdb_table(
-            attrs={'name': 'SpongeBob', 'external_ids': ext_ids})
+            attrs={'name': 'SpongeBob', 'other_config': other_config})
         old = new
         self.assertIsNone(self.event.handle_ha_chassis_group_changes(
             self.event.ROW_UPDATE, new, old))
diff --git a/neutron/tests/unit/plugins/ml2/drivers/ovn/mech_driver/test_mech_driver.py b/neutron/tests/unit/plugins/ml2/drivers/ovn/mech_driver/test_mech_driver.py
index 43f0214cd16..660ac27665d 100644
--- a/neutron/tests/unit/plugins/ml2/drivers/ovn/mech_driver/test_mech_driver.py
+++ b/neutron/tests/unit/plugins/ml2/drivers/ovn/mech_driver/test_mech_driver.py
@@ -105,6 +105,7 @@ def _add_chassis_agent(self, nb_cfg, agent_type, chassis_private=None):
                 chassis_private.nb_cfg_timestamp, mock.Mock):
             del chassis_private.nb_cfg_timestamp
         chassis_private.external_ids = {}
+        chassis_private.other_config = {}
         if agent_type == ovn_const.OVN_METADATA_AGENT:
             chassis_private.external_ids.update({
                 ovn_const.OVN_AGENT_METADATA_SB_CFG_KEY: nb_cfg,
diff --git a/releasenotes/notes/ovn-chassis-other-config-7db15b9d10bf7f04.yaml b/releasenotes/notes/ovn-chassis-other-config-7db15b9d10bf7f04.yaml
new file mode 100644
index 00000000000..8123a03be6d
--- /dev/null
+++ b/releasenotes/notes/ovn-chassis-other-config-7db15b9d10bf7f04.yaml
@@ -0,0 +1,10 @@
+---
+other:
+  - |
+    Since OVN 20.06, the "Chassis" register configuration is stored in the
+    "other_config" field and replicated into "external_ids". This replication
+    is stopped in OVN 22.09. The ML2/OVN plugin tries to retrieve the "Chassis"
+    configuration from the "other_config" field first; if this field does not
+    exist (in OVN versions before 20.06), the plugin will use "external_ids"
+    field instead. Neutron will be compatible with the different OVN versions
+    (with and without "other_config" field).