diff --git a/neutron/api/rpc/agentnotifiers/l3_rpc_agent_api.py b/neutron/api/rpc/agentnotifiers/l3_rpc_agent_api.py
index d166c36227c..fff43c3404d 100644
--- a/neutron/api/rpc/agentnotifiers/l3_rpc_agent_api.py
+++ b/neutron/api/rpc/agentnotifiers/l3_rpc_agent_api.py
@@ -16,6 +16,7 @@
 import random
 
 from neutron_lib import constants
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from oslo_log import log as logging
 import oslo_messaging
@@ -56,7 +57,7 @@ class L3AgentNotifyAPI(object):
                             shuffle_agents):
         """Notify changed routers to hosting l3 agents."""
         adminContext = context if context.is_admin else context.elevated()
-        plugin = directory.get_plugin(constants.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
         for router_id in router_ids:
             hosts = plugin.get_hosts_to_notify(adminContext, router_id)
             if shuffle_agents:
@@ -85,7 +86,7 @@ class L3AgentNotifyAPI(object):
     def _notification(self, context, method, router_ids, operation,
                       shuffle_agents, schedule_routers=True):
         """Notify all the agents that are hosting the routers."""
-        plugin = directory.get_plugin(constants.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
         if not plugin:
             LOG.error(_LE('No plugin for L3 routing registered. Cannot notify '
                           'agents with the message %s'), method)
diff --git a/neutron/api/rpc/agentnotifiers/metering_rpc_agent_api.py b/neutron/api/rpc/agentnotifiers/metering_rpc_agent_api.py
index 8a24da3521b..fdbb2f28103 100644
--- a/neutron/api/rpc/agentnotifiers/metering_rpc_agent_api.py
+++ b/neutron/api/rpc/agentnotifiers/metering_rpc_agent_api.py
@@ -13,6 +13,7 @@
 # under the License.
 
 from neutron_lib import constants
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from oslo_log import log as logging
 import oslo_messaging
@@ -36,7 +37,7 @@ class MeteringAgentNotifyAPI(object):
     def _agent_notification(self, context, method, routers):
         """Notify l3 metering agents hosted by l3 agent hosts."""
         adminContext = context if context.is_admin else context.elevated()
-        plugin = directory.get_plugin(constants.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
 
         l3_routers = {}
         state = agentschedulers_db.get_admin_state_up_filter()
@@ -71,7 +72,7 @@ class MeteringAgentNotifyAPI(object):
 
     def _notification(self, context, method, routers):
         """Notify all the agents that are hosting the routers."""
-        plugin = directory.get_plugin(constants.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
         if utils.is_extension_supported(
             plugin, constants.L3_AGENT_SCHEDULER_EXT_ALIAS):
             self._agent_notification(context, method, routers)
diff --git a/neutron/api/rpc/handlers/l3_rpc.py b/neutron/api/rpc/handlers/l3_rpc.py
index fda7be1ddf3..6744f927e45 100644
--- a/neutron/api/rpc/handlers/l3_rpc.py
+++ b/neutron/api/rpc/handlers/l3_rpc.py
@@ -17,6 +17,7 @@ from neutron_lib.api.definitions import portbindings
 from neutron_lib import constants
 from neutron_lib import context as neutron_context
 from neutron_lib import exceptions
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from oslo_config import cfg
 from oslo_log import log as logging
@@ -56,7 +57,7 @@ class L3RpcCallback(object):
     @property
     def l3plugin(self):
         if not hasattr(self, '_l3plugin'):
-            self._l3plugin = directory.get_plugin(constants.L3)
+            self._l3plugin = directory.get_plugin(plugin_constants.L3)
         return self._l3plugin
 
     def _update_ha_network_port_status(self, context, host_id):
diff --git a/neutron/api/v2/resource_helper.py b/neutron/api/v2/resource_helper.py
index f8050ba72aa..0643f134b1a 100644
--- a/neutron/api/v2/resource_helper.py
+++ b/neutron/api/v2/resource_helper.py
@@ -13,7 +13,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from neutron_lib import constants
+from neutron_lib.plugins import constants
 from neutron_lib.plugins import directory
 from oslo_log import log as logging
 
diff --git a/neutron/cmd/eventlet/usage_audit.py b/neutron/cmd/eventlet/usage_audit.py
index 44eb85b0d3e..888f0aa89fb 100644
--- a/neutron/cmd/eventlet/usage_audit.py
+++ b/neutron/cmd/eventlet/usage_audit.py
@@ -19,8 +19,8 @@ subnets.
 
 import sys
 
-from neutron_lib import constants
 from neutron_lib import context
+from neutron_lib.plugins import constants
 from neutron_lib.plugins import directory
 
 from neutron.common import config
diff --git a/neutron/db/availability_zone/router.py b/neutron/db/availability_zone/router.py
index 8db67d1d175..7a95e9d6efe 100644
--- a/neutron/db/availability_zone/router.py
+++ b/neutron/db/availability_zone/router.py
@@ -14,7 +14,7 @@
 from neutron_lib.callbacks import events
 from neutron_lib.callbacks import registry
 from neutron_lib.callbacks import resources
-from neutron_lib import constants
+from neutron_lib.plugins import constants
 from neutron_lib.plugins import directory
 
 from neutron.common import utils
diff --git a/neutron/db/db_base_plugin_v2.py b/neutron/db/db_base_plugin_v2.py
index aad546147d9..8d0267376b1 100644
--- a/neutron/db/db_base_plugin_v2.py
+++ b/neutron/db/db_base_plugin_v2.py
@@ -24,6 +24,7 @@ from neutron_lib.callbacks import resources
 from neutron_lib import constants
 from neutron_lib import context as ctx
 from neutron_lib import exceptions as exc
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from oslo_config import cfg
 from oslo_db import exception as os_db_exc
@@ -621,7 +622,7 @@ class NeutronDbPluginV2(db_base_plugin_common.DbBasePluginCommon,
             raise exc.BadRequest(resource='subnets', msg=reason)
 
     def _update_router_gw_ports(self, context, network, subnet):
-        l3plugin = directory.get_plugin(constants.L3)
+        l3plugin = directory.get_plugin(plugin_constants.L3)
         if l3plugin:
             gw_ports = self._get_router_gw_ports_by_network(context,
                     network['id'])
@@ -635,7 +636,7 @@ class NeutronDbPluginV2(db_base_plugin_common.DbBasePluginCommon,
                               {'id': id, 's': subnet})
 
     def _update_router_gw_port(self, context, router_id, network, subnet):
-        l3plugin = directory.get_plugin(constants.L3)
+        l3plugin = directory.get_plugin(plugin_constants.L3)
         ctx_admin = context.elevated()
         ext_subnets_dict = {s['id']: s for s in network['subnets']}
         router = l3plugin.get_router(ctx_admin, router_id)
@@ -1406,7 +1407,7 @@ class NeutronDbPluginV2(db_base_plugin_common.DbBasePluginCommon,
                     except l3.RouterNotFound:
                         return
                 else:
-                    l3plugin = directory.get_plugin(constants.L3)
+                    l3plugin = directory.get_plugin(plugin_constants.L3)
                     if l3plugin:
                         try:
                             ctx_admin = context.elevated()
diff --git a/neutron/db/external_net_db.py b/neutron/db/external_net_db.py
index a07299c0d10..b6a1aec1010 100644
--- a/neutron/db/external_net_db.py
+++ b/neutron/db/external_net_db.py
@@ -19,6 +19,7 @@ from neutron_lib.callbacks import registry
 from neutron_lib.callbacks import resources
 from neutron_lib import constants
 from neutron_lib import exceptions as n_exc
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from sqlalchemy.sql import expression as expr
 
@@ -139,7 +140,7 @@ class External_net_db_mixin(object):
             net_data[external_net.EXTERNAL] = False
 
     def _process_l3_delete(self, context, network_id):
-        l3plugin = directory.get_plugin(constants.L3)
+        l3plugin = directory.get_plugin(plugin_constants.L3)
         if l3plugin:
             l3plugin.delete_disassociated_floatingips(context, network_id)
 
diff --git a/neutron/db/l3_agentschedulers_db.py b/neutron/db/l3_agentschedulers_db.py
index b4a6acef1cd..d2d87d679ec 100644
--- a/neutron/db/l3_agentschedulers_db.py
+++ b/neutron/db/l3_agentschedulers_db.py
@@ -14,6 +14,7 @@
 #    under the License.
 
 from neutron_lib import constants
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from oslo_config import cfg
 from oslo_db import exception as db_exc
@@ -152,7 +153,7 @@ class L3AgentSchedulerDbMixin(l3agentscheduler.L3AgentSchedulerPluginBase,
         router_id = router['id']
         agent_id = agent['id']
         if self.router_scheduler:
-            plugin = directory.get_plugin(constants.L3)
+            plugin = directory.get_plugin(plugin_constants.L3)
             try:
                 if router.get('ha'):
                     self.router_scheduler.create_ha_port_and_bind(
@@ -199,7 +200,7 @@ class L3AgentSchedulerDbMixin(l3agentscheduler.L3AgentSchedulerPluginBase,
         self._unbind_router(context, router_id, agent_id)
 
         router = self.get_router(context, router_id)
-        plugin = directory.get_plugin(constants.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
         if router.get('ha'):
             plugin.delete_ha_interfaces_on_host(context, router_id, agent.host)
         # NOTE(Swami): Need to verify if there are DVR serviceable
diff --git a/neutron/db/l3_db.py b/neutron/db/l3_db.py
index 6b2111a67a4..4655834d917 100644
--- a/neutron/db/l3_db.py
+++ b/neutron/db/l3_db.py
@@ -26,6 +26,7 @@ from neutron_lib.callbacks import resources
 from neutron_lib import constants
 from neutron_lib import context as n_ctx
 from neutron_lib import exceptions as n_exc
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from neutron_lib.services import base as base_services
 from oslo_log import log as logging
@@ -95,7 +96,7 @@ class L3_NAT_dbonly_mixin(l3.RouterPluginBase,
         context = kwargs['context']
         port_id = kwargs['port_id']
         port_check = kwargs['port_check']
-        l3plugin = directory.get_plugin(constants.L3)
+        l3plugin = directory.get_plugin(plugin_constants.L3)
         if l3plugin and port_check:
             l3plugin.prevent_l3_port_deletion(context, port_id)
 
@@ -271,7 +272,7 @@ class L3_NAT_dbonly_mixin(l3.RouterPluginBase,
             candidates = None
         router_db = self._update_router_db(context, id, r)
         if candidates:
-            l3_plugin = directory.get_plugin(constants.L3)
+            l3_plugin = directory.get_plugin(plugin_constants.L3)
             l3_plugin.reschedule_router(context, id, candidates)
         updated = self._make_router_dict(router_db)
         registry.notify(resources.ROUTER, events.AFTER_UPDATE, self,
@@ -307,7 +308,7 @@ class L3_NAT_dbonly_mixin(l3.RouterPluginBase,
 
         # first get plugin supporting l3 agent scheduling
         # (either l3 service plugin or core_plugin)
-        l3_plugin = directory.get_plugin(constants.L3)
+        l3_plugin = directory.get_plugin(plugin_constants.L3)
         if (not utils.is_extension_supported(
                 l3_plugin,
                 constants.L3_AGENT_SCHEDULER_EXT_ALIAS) or
@@ -1753,16 +1754,16 @@ class L3RpcNotifierMixin(object):
     def _notify_routers_callback(resource, event, trigger, **kwargs):
         context = kwargs['context']
         router_ids = kwargs['router_ids']
-        l3plugin = directory.get_plugin(constants.L3)
+        l3plugin = directory.get_plugin(plugin_constants.L3)
         if l3plugin:
             l3plugin.notify_routers_updated(context, router_ids)
         else:
-            LOG.debug('%s not configured', constants.L3)
+            LOG.debug('%s not configured', plugin_constants.L3)
 
     @staticmethod
     @registry.receives(resources.SUBNET, [events.AFTER_UPDATE])
     def _notify_subnet_gateway_ip_update(resource, event, trigger, **kwargs):
-        l3plugin = directory.get_plugin(constants.L3)
+        l3plugin = directory.get_plugin(plugin_constants.L3)
         if not l3plugin:
             return
         context = kwargs['context']
@@ -1800,11 +1801,11 @@ class L3RpcNotifierMixin(object):
         query = query.distinct()
 
         router_ids = [r[0] for r in query]
-        l3plugin = directory.get_plugin(constants.L3)
+        l3plugin = directory.get_plugin(plugin_constants.L3)
         if l3plugin:
             l3plugin.notify_routers_updated(context, router_ids)
         else:
-            LOG.debug('%s not configured', constants.L3)
+            LOG.debug('%s not configured', plugin_constants.L3)
 
     @property
     def l3_rpc_notifier(self):
diff --git a/neutron/db/l3_dvr_db.py b/neutron/db/l3_dvr_db.py
index 3189e6667fc..2ce8af5b3e6 100644
--- a/neutron/db/l3_dvr_db.py
+++ b/neutron/db/l3_dvr_db.py
@@ -21,6 +21,7 @@ from neutron_lib.callbacks import registry
 from neutron_lib.callbacks import resources
 from neutron_lib import constants as const
 from neutron_lib import exceptions as n_exc
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from oslo_config import cfg
 from oslo_log import helpers as log_helper
@@ -70,7 +71,7 @@ class DVRResourceOperationHandler(object):
 
     @property
     def l3plugin(self):
-        return directory.get_plugin(const.L3)
+        return directory.get_plugin(plugin_constants.L3)
 
     @registry.receives(resources.ROUTER, [events.PRECOMMIT_CREATE])
     def _set_distributed_flag(self, resource, event, trigger, context,
@@ -500,7 +501,7 @@ class DVRResourceOperationHandler(object):
         if not router.extra_attributes.distributed:
             return
 
-        plugin = directory.get_plugin(const.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
 
         # we calculate which hosts to notify by checking the hosts for
         # the removed port's subnets and then subtract out any hosts still
diff --git a/neutron/db/l3_dvrscheduler_db.py b/neutron/db/l3_dvrscheduler_db.py
index 1de66da4616..d31f80b2158 100644
--- a/neutron/db/l3_dvrscheduler_db.py
+++ b/neutron/db/l3_dvrscheduler_db.py
@@ -18,6 +18,7 @@ from neutron_lib.callbacks import events
 from neutron_lib.callbacks import registry
 from neutron_lib.callbacks import resources
 from neutron_lib import constants as n_const
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from oslo_log import log as logging
 from sqlalchemy import or_
@@ -94,7 +95,7 @@ class L3_DVRsch_db_mixin(l3agent_sch_db.L3AgentSchedulerDbMixin):
             # Make sure we create the floatingip agent gateway port
             # for the destination node if fip is associated with this
             # fixed port
-            l3plugin = directory.get_plugin(n_const.L3)
+            l3plugin = directory.get_plugin(plugin_constants.L3)
             (
                 l3plugin.
                 check_for_fip_and_create_agent_gw_port_on_host_if_not_exists(
@@ -373,7 +374,7 @@ def _notify_l3_agent_new_port(resource, event, trigger, **kwargs):
         return
 
     if n_utils.is_dvr_serviced(port['device_owner']):
-        l3plugin = directory.get_plugin(n_const.L3)
+        l3plugin = directory.get_plugin(plugin_constants.L3)
         context = kwargs['context']
         l3plugin.dvr_handle_new_service_port(context, port)
         l3plugin.update_arp_entry_for_dvr_service_port(context, port)
@@ -382,7 +383,7 @@ def _notify_l3_agent_new_port(resource, event, trigger, **kwargs):
 def _notify_port_delete(event, resource, trigger, **kwargs):
     context = kwargs['context']
     port = kwargs['port']
-    l3plugin = directory.get_plugin(n_const.L3)
+    l3plugin = directory.get_plugin(plugin_constants.L3)
     if port:
         port_host = port.get(portbindings.HOST_ID)
         allowed_address_pairs_list = port.get('allowed_address_pairs')
@@ -405,7 +406,7 @@ def _notify_l3_agent_port_update(resource, event, trigger, **kwargs):
         original_device_owner = original_port.get('device_owner', '')
         new_device_owner = new_port.get('device_owner', '')
         is_new_device_dvr_serviced = n_utils.is_dvr_serviced(new_device_owner)
-        l3plugin = directory.get_plugin(n_const.L3)
+        l3plugin = directory.get_plugin(plugin_constants.L3)
         context = kwargs['context']
         is_port_no_longer_serviced = (
             n_utils.is_dvr_serviced(original_device_owner) and
diff --git a/neutron/db/l3_hascheduler_db.py b/neutron/db/l3_hascheduler_db.py
index 5f9d21a2399..e9a6b2e164c 100644
--- a/neutron/db/l3_hascheduler_db.py
+++ b/neutron/db/l3_hascheduler_db.py
@@ -17,6 +17,7 @@ from neutron_lib.callbacks import events
 from neutron_lib.callbacks import registry
 from neutron_lib.callbacks import resources
 from neutron_lib import constants
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 
 from neutron.db import l3_agentschedulers_db as l3_sch_db
@@ -64,7 +65,7 @@ def _notify_l3_agent_ha_port_update(resource, event, trigger, **kwargs):
         if (new_device_owner == constants.DEVICE_OWNER_ROUTER_HA_INTF and
             new_port['status'] == constants.PORT_STATUS_ACTIVE and
             original_port['status'] != new_port['status']):
-            l3plugin = directory.get_plugin(constants.L3)
+            l3plugin = directory.get_plugin(plugin_constants.L3)
             l3plugin.l3_rpc_notifier.routers_updated_on_host(
                 context, [new_port['device_id']], host)
 
diff --git a/neutron/db/metering/metering_rpc.py b/neutron/db/metering/metering_rpc.py
index bc943a92a38..68d7982fe23 100644
--- a/neutron/db/metering/metering_rpc.py
+++ b/neutron/db/metering/metering_rpc.py
@@ -13,6 +13,7 @@
 # under the License.
 
 from neutron_lib import constants as consts
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from oslo_log import log as logging
 import oslo_messaging
@@ -31,7 +32,7 @@ class MeteringRpcCallbacks(object):
         self.meter_plugin = meter_plugin
 
     def get_sync_data_metering(self, context, **kwargs):
-        l3_plugin = directory.get_plugin(consts.L3)
+        l3_plugin = directory.get_plugin(plugin_constants.L3)
         if not l3_plugin:
             return
 
diff --git a/neutron/extensions/l3.py b/neutron/extensions/l3.py
index a150bd3d7e1..80def7487cb 100644
--- a/neutron/extensions/l3.py
+++ b/neutron/extensions/l3.py
@@ -17,9 +17,9 @@ import abc
 
 from neutron_lib.api import converters
 from neutron_lib.api import extensions
-from neutron_lib import constants
 from neutron_lib.db import constants as db_const
 from neutron_lib import exceptions as nexception
+from neutron_lib.plugins import constants
 import six
 
 from neutron._i18n import _
diff --git a/neutron/extensions/l3agentscheduler.py b/neutron/extensions/l3agentscheduler.py
index 8d9c4654f31..db5b98048c3 100644
--- a/neutron/extensions/l3agentscheduler.py
+++ b/neutron/extensions/l3agentscheduler.py
@@ -18,6 +18,7 @@ import abc
 from neutron_lib.api import extensions as api_extensions
 from neutron_lib import constants
 from neutron_lib import exceptions
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from oslo_log import log as logging
 import six
@@ -44,7 +45,7 @@ L3_AGENTS = L3_AGENT + 's'
 
 class RouterSchedulerController(wsgi.Controller):
     def get_plugin(self):
-        plugin = directory.get_plugin(constants.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
         if not plugin:
             LOG.error(_LE('No plugin for L3 routing registered to handle '
                           'router scheduling'))
@@ -86,7 +87,7 @@ class RouterSchedulerController(wsgi.Controller):
 
 class L3AgentsHostingRouterController(wsgi.Controller):
     def get_plugin(self):
-        plugin = directory.get_plugin(constants.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
         if not plugin:
             LOG.error(_LE('No plugin for L3 routing registered to handle '
                           'router scheduling'))
diff --git a/neutron/manager.py b/neutron/manager.py
index 6d763e47efe..75f83a491a7 100644
--- a/neutron/manager.py
+++ b/neutron/manager.py
@@ -14,7 +14,7 @@
 #    under the License.
 
 from collections import defaultdict
-from neutron_lib import constants as lib_const
+from neutron_lib.plugins import constants as lib_const
 from neutron_lib.plugins import directory
 from oslo_config import cfg
 from oslo_log import log as logging
diff --git a/neutron/plugins/common/constants.py b/neutron/plugins/common/constants.py
index a8524bd7bdd..7599e903781 100644
--- a/neutron/plugins/common/constants.py
+++ b/neutron/plugins/common/constants.py
@@ -13,7 +13,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from neutron_lib import constants
+from neutron_lib.plugins import constants
 
 
 # Neutron well-known service type constants:
diff --git a/neutron/plugins/ml2/drivers/l2pop/mech_driver.py b/neutron/plugins/ml2/drivers/l2pop/mech_driver.py
index c57643f8bad..d4befda6aab 100644
--- a/neutron/plugins/ml2/drivers/l2pop/mech_driver.py
+++ b/neutron/plugins/ml2/drivers/l2pop/mech_driver.py
@@ -16,6 +16,7 @@
 from neutron_lib import constants as const
 from neutron_lib import context as n_context
 from neutron_lib import exceptions
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from neutron_lib.plugins.ml2 import api
 from oslo_config import cfg
@@ -242,7 +243,7 @@ class L2populationMechanismDriver(api.MechanismDriver):
     def update_port_down(self, context):
         port = context.current
         agent_host = context.host
-        l3plugin = directory.get_plugin(const.L3)
+        l3plugin = directory.get_plugin(plugin_constants.L3)
         # when agent transitions to backup, don't remove flood flows
         if agent_host and l3plugin and getattr(
             l3plugin, "list_router_ids_on_host", None):
diff --git a/neutron/plugins/ml2/plugin.py b/neutron/plugins/ml2/plugin.py
index 73b3b1d8026..24410cfbe0f 100644
--- a/neutron/plugins/ml2/plugin.py
+++ b/neutron/plugins/ml2/plugin.py
@@ -26,6 +26,7 @@ from neutron_lib.callbacks import resources
 from neutron_lib import constants as const
 from neutron_lib import exceptions as exc
 from neutron_lib.exceptions import port_security as psec_exc
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from neutron_lib.plugins.ml2 import api
 from oslo_config import cfg
@@ -1431,7 +1432,7 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
         self._pre_delete_port(context, id, l3_port_check)
         # TODO(armax): get rid of the l3 dependency in the with block
         router_ids = []
-        l3plugin = directory.get_plugin(const.L3)
+        l3plugin = directory.get_plugin(plugin_constants.L3)
 
         with db_api.context_manager.writer.using(context):
             try:
diff --git a/neutron/services/auto_allocate/db.py b/neutron/services/auto_allocate/db.py
index eba96be6bb0..48910ce573b 100644
--- a/neutron/services/auto_allocate/db.py
+++ b/neutron/services/auto_allocate/db.py
@@ -17,8 +17,8 @@
 from neutron_lib.callbacks import events
 from neutron_lib.callbacks import registry
 from neutron_lib.callbacks import resources
-from neutron_lib import constants
 from neutron_lib import exceptions as n_exc
+from neutron_lib.plugins import constants
 from neutron_lib.plugins import directory
 from oslo_log import log as logging
 
diff --git a/neutron/services/l3_router/l3_router_plugin.py b/neutron/services/l3_router/l3_router_plugin.py
index cbf893aff33..287284c40f1 100644
--- a/neutron/services/l3_router/l3_router_plugin.py
+++ b/neutron/services/l3_router/l3_router_plugin.py
@@ -14,6 +14,7 @@
 #    under the License.
 
 from neutron_lib import constants as n_const
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.services import base as service_base
 from oslo_config import cfg
 from oslo_log import helpers as log_helpers
@@ -116,7 +117,7 @@ class L3RouterPlugin(service_base.ServicePluginBase,
 
     @classmethod
     def get_plugin_type(cls):
-        return n_const.L3
+        return plugin_constants.L3
 
     def get_plugin_description(self):
         """returns string description of the plugin."""
diff --git a/neutron/services/l3_router/service_providers/driver_controller.py b/neutron/services/l3_router/service_providers/driver_controller.py
index d5c7ee8fa60..078a76996d9 100644
--- a/neutron/services/l3_router/service_providers/driver_controller.py
+++ b/neutron/services/l3_router/service_providers/driver_controller.py
@@ -17,6 +17,7 @@ from neutron_lib.callbacks import registry
 from neutron_lib.callbacks import resources
 from neutron_lib import constants as lib_const
 from neutron_lib import exceptions as lib_exc
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from oslo_config import cfg
 from oslo_log import log as logging
@@ -46,12 +47,12 @@ class DriverController(object):
         self.l3_plugin = l3_plugin
         self._stm = st_db.ServiceTypeManager.get_instance()
         self._stm.add_provider_configuration(
-                lib_const.L3, _LegacyPlusProviderConfiguration())
+                plugin_constants.L3, _LegacyPlusProviderConfiguration())
         self._load_drivers()
 
     def _load_drivers(self):
         self.drivers, self.default_provider = (
-            service_base.load_drivers(lib_const.L3, self.l3_plugin))
+            service_base.load_drivers(plugin_constants.L3, self.l3_plugin))
         # store the provider name on each driver to make finding inverse easy
         for provider_name, driver in self.drivers.items():
             setattr(driver, 'name', provider_name)
@@ -81,7 +82,7 @@ class DriverController(object):
         if _flavor_specified(router):
             router_db.flavor_id = router['flavor_id']
         drv = self._get_provider_for_create(context, router)
-        self._stm.add_resource_association(context, lib_const.L3,
+        self._stm.add_resource_association(context, plugin_constants.L3,
                                            drv.name, router['id'])
 
     @registry.receives(resources.ROUTER, [events.PRECOMMIT_DELETE])
@@ -140,7 +141,7 @@ class DriverController(object):
             with context.session.begin(subtransactions=True):
                 self._stm.del_resource_associations(context, [router_id])
                 self._stm.add_resource_association(
-                    context, lib_const.L3, new_drv.name, router_id)
+                    context, plugin_constants.L3, new_drv.name, router_id)
 
     def get_provider_for_router(self, context, router_id):
         """Return the provider driver handle for a router id."""
@@ -152,7 +153,7 @@ class DriverController(object):
             router = self.l3_plugin.get_router(context, router_id)
             driver = self._attrs_to_driver(router)
             driver_name = driver.name
-            self._stm.add_resource_association(context, lib_const.L3,
+            self._stm.add_resource_association(context, plugin_constants.L3,
                                                driver_name, router_id)
         return self.drivers[driver_name]
 
@@ -208,7 +209,7 @@ class _LegacyPlusProviderConfiguration(
                              ('single_node', 'single_node.SingleNodeDriver')):
             path = 'neutron.services.l3_router.service_providers.%s' % driver
             try:
-                self.add_provider({'service_type': lib_const.L3,
+                self.add_provider({'service_type': plugin_constants.L3,
                                    'name': name, 'driver': path,
                                    'default': False})
             except lib_exc.Invalid:
diff --git a/neutron/tests/functional/pecan_wsgi/test_controllers.py b/neutron/tests/functional/pecan_wsgi/test_controllers.py
index b24edd44e9b..c8daff5aad1 100644
--- a/neutron/tests/functional/pecan_wsgi/test_controllers.py
+++ b/neutron/tests/functional/pecan_wsgi/test_controllers.py
@@ -13,6 +13,7 @@
 import mock
 from neutron_lib import constants as n_const
 from neutron_lib import context
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from oslo_config import cfg
 from oslo_db import exception as db_exc
@@ -689,7 +690,7 @@ class TestRequestProcessing(TestRootController):
         self.assertEqual('router', self.req_stash['resource_type'])
         # make sure the core plugin was identified as the handler for ports
         self.assertEqual(
-            directory.get_plugin(n_const.L3),
+            directory.get_plugin(plugin_constants.L3),
             self.req_stash['plugin'])
 
     def test_service_plugin_uri(self):
@@ -719,7 +720,7 @@ class TestRouterController(TestResourceController):
         self.addCleanup(policy.reset)
         plugin = directory.get_plugin()
         ctx = context.get_admin_context()
-        l3_plugin = directory.get_plugin(n_const.L3)
+        l3_plugin = directory.get_plugin(plugin_constants.L3)
         network_id = pecan_utils.create_network(ctx, plugin)['id']
         self.subnet = pecan_utils.create_subnet(ctx, plugin, network_id)
         self.router = pecan_utils.create_router(ctx, l3_plugin)
@@ -820,7 +821,7 @@ class TestL3AgentShimControllers(test_functional.PecanFunctionalTest):
                  'get_l3-routers': 'role:admin'}),
             overwrite=False)
         ctx = context.get_admin_context()
-        l3_plugin = directory.get_plugin(n_const.L3)
+        l3_plugin = directory.get_plugin(plugin_constants.L3)
         self.router = pecan_utils.create_router(ctx, l3_plugin)
         self.agent = helpers.register_l3_agent()
         # NOTE(blogan): Not sending notifications because this test is for
diff --git a/neutron/tests/functional/pecan_wsgi/test_functional.py b/neutron/tests/functional/pecan_wsgi/test_functional.py
index 38b27ab2972..67310498328 100644
--- a/neutron/tests/functional/pecan_wsgi/test_functional.py
+++ b/neutron/tests/functional/pecan_wsgi/test_functional.py
@@ -16,9 +16,9 @@
 import os
 
 import mock
-from neutron_lib import constants
 from neutron_lib import context
 from neutron_lib import exceptions as n_exc
+from neutron_lib.plugins import constants
 from oslo_config import cfg
 from oslo_middleware import base
 from oslo_service import wsgi
diff --git a/neutron/tests/functional/scheduler/test_l3_agent_scheduler.py b/neutron/tests/functional/scheduler/test_l3_agent_scheduler.py
index b372a503475..497d1b0dbc7 100644
--- a/neutron/tests/functional/scheduler/test_l3_agent_scheduler.py
+++ b/neutron/tests/functional/scheduler/test_l3_agent_scheduler.py
@@ -18,6 +18,7 @@ import random
 
 from neutron_lib import constants
 from neutron_lib import context
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from oslo_utils import uuidutils
 import testscenarios
@@ -46,7 +47,7 @@ class L3SchedulerBaseTest(test_db_base_plugin_v2.NeutronDbPluginV2TestCase):
         super(L3SchedulerBaseTest, self).setUp(PLUGIN_NAME)
 
         self.l3_plugin = l3_router_plugin.L3RouterPlugin()
-        directory.add_plugin(constants.L3, self.l3_plugin)
+        directory.add_plugin(plugin_constants.L3, self.l3_plugin)
         self.adminContext = context.get_admin_context()
         self.adminContext.tenant_id = _uuid()
 
@@ -298,9 +299,9 @@ class L3AZSchedulerBaseTest(test_db_base_plugin_v2.NeutronDbPluginV2TestCase):
         super(L3AZSchedulerBaseTest, self).setUp(plugin='ml2')
 
         self.l3_plugin = l3_router_plugin.L3RouterPlugin()
-        directory.add_plugin(constants.L3, self.l3_plugin)
+        directory.add_plugin(plugin_constants.L3, self.l3_plugin)
         self.l3_plugin.router_scheduler = None
-        directory.add_plugin(constants.L3, self.l3_plugin)
+        directory.add_plugin(plugin_constants.L3, self.l3_plugin)
         self.adminContext = context.get_admin_context()
         self.adminContext.tenant_id = '_func_test_tenant_'
 
diff --git a/neutron/tests/tempest/api/admin/test_routers_flavors.py b/neutron/tests/tempest/api/admin/test_routers_flavors.py
index d0c2f2863f6..4153c2d3839 100644
--- a/neutron/tests/tempest/api/admin/test_routers_flavors.py
+++ b/neutron/tests/tempest/api/admin/test_routers_flavors.py
@@ -11,7 +11,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from neutron_lib import constants
+from neutron_lib.plugins import constants
 from tempest.lib import decorators
 from tempest.lib import exceptions as lib_exc
 import testtools
diff --git a/neutron/tests/unit/agent/l3/test_agent.py b/neutron/tests/unit/agent/l3/test_agent.py
index 2bced67a8b5..84528068c61 100644
--- a/neutron/tests/unit/agent/l3/test_agent.py
+++ b/neutron/tests/unit/agent/l3/test_agent.py
@@ -23,6 +23,7 @@ import netaddr
 from neutron_lib.api.definitions import portbindings
 from neutron_lib import constants as lib_constants
 from neutron_lib import exceptions as exc
+from neutron_lib.plugins import constants as plugin_constants
 from oslo_config import cfg
 from oslo_log import log
 import oslo_messaging
@@ -2534,7 +2535,7 @@ class TestBasicRouterOperations(BasicRouterOperationsFramework):
             self.assertEqual(2, mocked_func.call_count)
 
     def test_get_service_plugin_list(self):
-        service_plugins = [lib_constants.L3]
+        service_plugins = [plugin_constants.L3]
         self.plugin_api.get_service_plugin_list.return_value = service_plugins
         agent = l3_agent.L3NATAgent(HOSTNAME, self.conf)
         self.assertEqual(service_plugins, agent.neutron_service_plugins)
diff --git a/neutron/tests/unit/api/rpc/handlers/test_dhcp_rpc.py b/neutron/tests/unit/api/rpc/handlers/test_dhcp_rpc.py
index 365346897e5..9345c52b372 100644
--- a/neutron/tests/unit/api/rpc/handlers/test_dhcp_rpc.py
+++ b/neutron/tests/unit/api/rpc/handlers/test_dhcp_rpc.py
@@ -18,6 +18,7 @@ from neutron_lib.api.definitions import portbindings
 from neutron_lib.callbacks import resources
 from neutron_lib import constants
 from neutron_lib import exceptions as n_exc
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from oslo_db import exception as db_exc
 
@@ -34,7 +35,7 @@ class TestDhcpRpcCallback(base.BaseTestCase):
     def setUp(self):
         super(TestDhcpRpcCallback, self).setUp()
         self.plugin = mock.MagicMock()
-        directory.add_plugin(constants.CORE, self.plugin)
+        directory.add_plugin(plugin_constants.CORE, self.plugin)
         self.callbacks = dhcp_rpc.DhcpRpcCallback()
         self.log_p = mock.patch('neutron.api.rpc.handlers.dhcp_rpc.LOG')
         self.log = self.log_p.start()
diff --git a/neutron/tests/unit/api/test_extensions.py b/neutron/tests/unit/api/test_extensions.py
index db8cc33d3df..5f7d472da95 100644
--- a/neutron/tests/unit/api/test_extensions.py
+++ b/neutron/tests/unit/api/test_extensions.py
@@ -17,7 +17,7 @@ import copy
 
 import fixtures
 import mock
-from neutron_lib import constants as lib_const
+from neutron_lib.plugins import constants as lib_const
 from neutron_lib.plugins import directory
 from neutron_lib.services import base as service_base
 from oslo_config import cfg
diff --git a/neutron/tests/unit/db/quota/test_api.py b/neutron/tests/unit/db/quota/test_api.py
index 5b4c1746962..8eda029413b 100644
--- a/neutron/tests/unit/db/quota/test_api.py
+++ b/neutron/tests/unit/db/quota/test_api.py
@@ -15,8 +15,8 @@
 import datetime
 
 import mock
-from neutron_lib import constants as const
 from neutron_lib import context
+from neutron_lib.plugins import constants as const
 from neutron_lib.plugins import directory
 from oslo_config import cfg
 
diff --git a/neutron/tests/unit/db/test_agentschedulers_db.py b/neutron/tests/unit/db/test_agentschedulers_db.py
index abaf0c532d4..3155b7d9e99 100644
--- a/neutron/tests/unit/db/test_agentschedulers_db.py
+++ b/neutron/tests/unit/db/test_agentschedulers_db.py
@@ -18,6 +18,7 @@ import datetime
 import mock
 from neutron_lib import constants
 from neutron_lib import context
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from oslo_config import cfg
 from oslo_db import exception as db_exc
@@ -259,7 +260,7 @@ class OvsAgentSchedulerTestCaseBase(test_l3.L3NatTestCaseMixin,
         # the global attribute map
         attributes.RESOURCE_ATTRIBUTE_MAP.update(
             agent.RESOURCE_ATTRIBUTE_MAP)
-        self.l3plugin = directory.get_plugin(constants.L3)
+        self.l3plugin = directory.get_plugin(plugin_constants.L3)
         self.l3_notify_p = mock.patch(
             'neutron.extensions.l3agentscheduler.notify')
         self.patched_l3_notify = self.l3_notify_p.start()
@@ -675,7 +676,7 @@ class OvsAgentSchedulerTestCase(OvsAgentSchedulerTestCaseBase):
             agt.heartbeat_timestamp - datetime.timedelta(hours=1))
         self.adminContext.session.commit()
 
-        plugin = directory.get_plugin(constants.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
         plugin.reschedule_routers_from_down_agents()
 
     def _set_agent_admin_state_up(self, host, state):
@@ -692,7 +693,7 @@ class OvsAgentSchedulerTestCase(OvsAgentSchedulerTestCaseBase):
             # schedule the router to host A
             l3_rpc_cb.get_router_ids(self.adminContext, host=L3_HOSTA)
 
-            plugin = directory.get_plugin(constants.L3)
+            plugin = directory.get_plugin(plugin_constants.L3)
             mock.patch.object(
                 plugin, 'reschedule_router',
                 side_effect=[
@@ -713,12 +714,12 @@ class OvsAgentSchedulerTestCase(OvsAgentSchedulerTestCaseBase):
             mock_ctx = mock.Mock()
             get_ctx.return_value = mock_ctx
             mock_ctx.session.query.side_effect = db_exc.DBError()
-            plugin = directory.get_plugin(constants.L3)
+            plugin = directory.get_plugin(plugin_constants.L3)
             # check that no exception is raised
             plugin.reschedule_routers_from_down_agents()
 
     def test_router_rescheduler_iterates_after_reschedule_failure(self):
-        plugin = directory.get_plugin(constants.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
         l3_rpc_cb = l3_rpc.L3RpcCallback()
         self._register_agent_states()
         with self.router() as r1, self.router() as r2:
@@ -750,7 +751,7 @@ class OvsAgentSchedulerTestCase(OvsAgentSchedulerTestCaseBase):
                 self.assertFalse(rr.called)
 
     def test_router_is_not_rescheduled_if_agent_is_back_online(self):
-        plugin = directory.get_plugin(constants.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
         l3_rpc_cb = l3_rpc.L3RpcCallback()
         agent = helpers.register_l3_agent(host=L3_HOSTA)
         with self.router(),\
@@ -1487,7 +1488,7 @@ class OvsL3AgentNotifierTestCase(test_l3.L3NatTestCaseMixin,
         fake_notifier.reset()
 
     def test_router_add_to_l3_agent_notification(self):
-        l3_plugin = directory.get_plugin(constants.L3)
+        l3_plugin = directory.get_plugin(plugin_constants.L3)
         l3_notifier = l3_plugin.agent_notifiers[constants.AGENT_TYPE_L3]
         with mock.patch.object(
             l3_notifier.client,
@@ -1509,7 +1510,7 @@ class OvsL3AgentNotifierTestCase(test_l3.L3NatTestCaseMixin,
             self._assert_notify(notifications, expected_event_type)
 
     def test_router_remove_from_l3_agent_notification(self):
-        l3_plugin = directory.get_plugin(constants.L3)
+        l3_plugin = directory.get_plugin(plugin_constants.L3)
         l3_notifier = l3_plugin.agent_notifiers[constants.AGENT_TYPE_L3]
         with mock.patch.object(
             l3_notifier.client,
@@ -1534,7 +1535,7 @@ class OvsL3AgentNotifierTestCase(test_l3.L3NatTestCaseMixin,
             self._assert_notify(notifications, expected_event_type)
 
     def test_agent_updated_l3_agent_notification(self):
-        l3_plugin = directory.get_plugin(constants.L3)
+        l3_plugin = directory.get_plugin(plugin_constants.L3)
         l3_notifier = l3_plugin.agent_notifiers[constants.AGENT_TYPE_L3]
         with mock.patch.object(
             l3_notifier.client,
diff --git a/neutron/tests/unit/db/test_extraroute_db.py b/neutron/tests/unit/db/test_extraroute_db.py
index 0afcdf56aad..3e300d944d5 100644
--- a/neutron/tests/unit/db/test_extraroute_db.py
+++ b/neutron/tests/unit/db/test_extraroute_db.py
@@ -14,8 +14,8 @@
 #    under the License.
 
 import mock
-from neutron_lib import constants
 from neutron_lib import context
+from neutron_lib.plugins import constants
 from neutron_lib.plugins import directory
 
 from neutron.db import common_db_mixin
diff --git a/neutron/tests/unit/db/test_l3_dvr_db.py b/neutron/tests/unit/db/test_l3_dvr_db.py
index a42130f1bc9..6ffd5a1b564 100644
--- a/neutron/tests/unit/db/test_l3_dvr_db.py
+++ b/neutron/tests/unit/db/test_l3_dvr_db.py
@@ -21,6 +21,7 @@ from neutron_lib.callbacks import resources
 from neutron_lib import constants as const
 from neutron_lib import context
 from neutron_lib import exceptions
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from oslo_utils import uuidutils
 
@@ -48,7 +49,7 @@ class L3DvrTestCase(test_db_base_plugin_v2.NeutronDbPluginV2TestCase):
         self.core_plugin = directory.get_plugin()
         self.ctx = context.get_admin_context()
         self.mixin = FakeL3Plugin()
-        directory.add_plugin(const.L3, self.mixin)
+        directory.add_plugin(plugin_constants.L3, self.mixin)
 
     def _create_router(self, router):
         with self.ctx.session.begin(subtransactions=True):
@@ -173,7 +174,7 @@ class L3DvrTestCase(test_db_base_plugin_v2.NeutronDbPluginV2TestCase):
 
     def test__get_agent_gw_ports_exist_for_network(self):
         plugin = mock.Mock()
-        directory.add_plugin(const.CORE, plugin)
+        directory.add_plugin(plugin_constants.CORE, plugin)
         plugin.get_ports.return_value = []
         self.mixin._get_agent_gw_ports_exist_for_network(
             self.ctx, 'network_id', 'host', 'agent_id')
@@ -184,7 +185,7 @@ class L3DvrTestCase(test_db_base_plugin_v2.NeutronDbPluginV2TestCase):
 
     def _test_prepare_direct_delete_dvr_internal_ports(self, port):
         plugin = mock.Mock()
-        directory.add_plugin(const.CORE, plugin)
+        directory.add_plugin(plugin_constants.CORE, plugin)
         plugin.get_port.return_value = port
         self.mixin._router_exists = mock.Mock(return_value=True)
         self.assertRaises(exceptions.ServicePortInUse,
@@ -249,7 +250,7 @@ class L3DvrTestCase(test_db_base_plugin_v2.NeutronDbPluginV2TestCase):
             'device_owner': const.DEVICE_OWNER_ROUTER_GW
         }]
         plugin = mock.Mock()
-        directory.add_plugin(const.CORE, plugin)
+        directory.add_plugin(plugin_constants.CORE, plugin)
         plugin.get_ports.return_value = ports
         self.mixin.delete_floatingip_agent_gateway_port(
             self.ctx, port_host, 'ext_network_id')
@@ -286,7 +287,7 @@ class L3DvrTestCase(test_db_base_plugin_v2.NeutronDbPluginV2TestCase):
             router.gw_port = None
 
         plugin = mock.Mock()
-        directory.add_plugin(const.CORE, plugin)
+        directory.add_plugin(plugin_constants.CORE, plugin)
         with mock.patch.object(l3_dvr_db.l3_db.L3_NAT_db_mixin,
                                'router_gw_port_has_floating_ips',
                                return_value=False),\
@@ -690,7 +691,7 @@ class L3DvrTestCase(test_db_base_plugin_v2.NeutronDbPluginV2TestCase):
                        'distributed': True}
         router = self._create_router(router_dict)
         plugin = mock.Mock()
-        directory.add_plugin(const.CORE, plugin)
+        directory.add_plugin(plugin_constants.CORE, plugin)
         l3_notify = self.mixin.l3_rpc_notifier = mock.Mock()
         port = {
             'id': 'my_port_id',
diff --git a/neutron/tests/unit/db/test_l3_hamode_db.py b/neutron/tests/unit/db/test_l3_hamode_db.py
index 8e96c1d2a1d..05c5b2187bc 100644
--- a/neutron/tests/unit/db/test_l3_hamode_db.py
+++ b/neutron/tests/unit/db/test_l3_hamode_db.py
@@ -23,6 +23,7 @@ from neutron_lib.callbacks import resources
 from neutron_lib import constants
 from neutron_lib import context
 from neutron_lib import exceptions as n_exc
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from oslo_config import cfg
 from oslo_db import exception as db_exc
@@ -69,7 +70,7 @@ class L3HATestFramework(testlib_api.SqlTestCase):
         cfg.CONF.set_override('allow_overlapping_ips', True)
 
         self.plugin = FakeL3PluginWithAgents()
-        directory.add_plugin(constants.L3, self.plugin)
+        directory.add_plugin(plugin_constants.L3, self.plugin)
         self.plugin.router_scheduler = l3_agent_scheduler.ChanceScheduler()
         self.agent1 = helpers.register_l3_agent()
         self.agent2 = helpers.register_l3_agent(
diff --git a/neutron/tests/unit/db/test_portsecurity_db.py b/neutron/tests/unit/db/test_portsecurity_db.py
index e164cc5be91..f13eca4f795 100644
--- a/neutron/tests/unit/db/test_portsecurity_db.py
+++ b/neutron/tests/unit/db/test_portsecurity_db.py
@@ -11,7 +11,7 @@
 #    under the License.
 
 import mock
-from neutron_lib import constants
+from neutron_lib.plugins import constants
 from neutron_lib.plugins import directory
 
 from neutron.db import portsecurity_db as pd
diff --git a/neutron/tests/unit/extensions/test_external_net.py b/neutron/tests/unit/extensions/test_external_net.py
index c079e82be66..4da13b923d4 100644
--- a/neutron/tests/unit/extensions/test_external_net.py
+++ b/neutron/tests/unit/extensions/test_external_net.py
@@ -16,6 +16,7 @@
 import mock
 from neutron_lib import constants
 from neutron_lib import context
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from oslo_utils import uuidutils
 import testtools
@@ -185,7 +186,7 @@ class ExtNetDBTestCase(test_db_base_plugin_v2.NeutronDbPluginV2TestCase):
 
     def test_delete_network_check_disassociated_floatingips(self):
         l3_mock = mock.Mock()
-        directory.add_plugin(constants.L3, l3_mock)
+        directory.add_plugin(plugin_constants.L3, l3_mock)
         with self.network() as net:
             req = self.new_delete_request('networks', net['network']['id'])
             res = req.get_response(self.api)
diff --git a/neutron/tests/unit/extensions/test_l3.py b/neutron/tests/unit/extensions/test_l3.py
index 014d2a6061f..de1f134e641 100644
--- a/neutron/tests/unit/extensions/test_l3.py
+++ b/neutron/tests/unit/extensions/test_l3.py
@@ -27,6 +27,7 @@ from neutron_lib.callbacks import resources
 from neutron_lib import constants as lib_constants
 from neutron_lib import context
 from neutron_lib import exceptions as n_exc
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from oslo_config import cfg
 from oslo_utils import importutils
@@ -100,7 +101,7 @@ class L3NatExtensionTestCase(test_extensions_base.ExtensionTestCase):
         super(L3NatExtensionTestCase, self).setUp()
         self._setUpExtension(
             'neutron.services.l3_router.l3_router_plugin.L3RouterPlugin',
-            lib_constants.L3, l3.RESOURCE_ATTRIBUTE_MAP,
+            plugin_constants.L3, l3.RESOURCE_ATTRIBUTE_MAP,
             l3.L3, '', allow_pagination=True, allow_sorting=True,
             supported_extension_aliases=['router'],
             use_quota=True)
@@ -269,7 +270,7 @@ class TestL3NatBasePlugin(db_base_plugin_v2.NeutronDbPluginV2,
         return net
 
     def delete_port(self, context, id, l3_port_check=True):
-        plugin = directory.get_plugin(lib_constants.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
         if plugin:
             if l3_port_check:
                 plugin.prevent_l3_port_deletion(context, id)
@@ -322,7 +323,7 @@ class TestL3NatServicePlugin(common_db_mixin.CommonDbMixin,
 
     @classmethod
     def get_plugin_type(cls):
-        return lib_constants.L3
+        return plugin_constants.L3
 
     def get_plugin_description(self):
         return "L3 Routing Service Plugin for testing"
@@ -571,7 +572,7 @@ class ExtraAttributesMixinTestCase(testlib_api.SqlTestCase):
     def setUp(self):
         super(ExtraAttributesMixinTestCase, self).setUp()
         self.mixin = l3_attrs_db.ExtraAttributesMixin()
-        directory.add_plugin(lib_constants.L3, self.mixin)
+        directory.add_plugin(plugin_constants.L3, self.mixin)
         self.ctx = context.get_admin_context()
         self.router = l3_models.Router()
         with self.ctx.session.begin():
@@ -901,7 +902,7 @@ class L3NatTestCaseBase(L3NatTestCaseMixin):
                     r['router']['id'],
                     n['network']['id'],
                     ext_ips=[{'subnet_id': s1['subnet']['id']}])
-                plugin = directory.get_plugin(lib_constants.L3)
+                plugin = directory.get_plugin(plugin_constants.L3)
                 mock.patch.object(
                     plugin, 'update_router',
                     side_effect=l3.RouterNotFound(router_id='1')).start()
@@ -2131,7 +2132,7 @@ class L3NatTestCaseBase(L3NatTestCaseMixin):
             self.assertIsNotNone(body['floatingip']['router_id'])
 
     def test_create_floatingip_non_admin_context_agent_notification(self):
-        plugin = directory.get_plugin(lib_constants.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
         if not hasattr(plugin, 'l3_rpc_notifier'):
             self.skipTest("Plugin does not support l3_rpc_notifier")
 
@@ -2972,7 +2973,7 @@ class L3NatTestCaseBase(L3NatTestCaseMixin):
     def test_floatingip_via_router_interface_returns_201(self):
         # Override get_router_for_floatingip, as
         # networking-midonet's L3 service plugin would do.
-        plugin = directory.get_plugin(lib_constants.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
         with mock.patch.object(plugin, "get_router_for_floatingip",
             self._get_router_for_floatingip_without_device_owner_check):
             self._test_floatingip_via_router_interface(exc.HTTPCreated.code)
@@ -3112,7 +3113,7 @@ class L3NatTestCaseBase(L3NatTestCaseMixin):
             self.assertEqual(exc.HTTPConflict.code, res.status_int)
 
     def test_router_specify_id_backend(self):
-        plugin = directory.get_plugin(lib_constants.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
         router_req = {'router': {'id': _uuid(), 'name': 'router',
                                  'tenant_id': 'foo',
                                  'admin_state_up': True}}
@@ -3167,7 +3168,7 @@ class L3NatTestCaseBase(L3NatTestCaseMixin):
 
     def test_create_router_gateway_fails_nested(self):
         # Force _update_router_gw_info failure
-        plugin = directory.get_plugin(lib_constants.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
         if not isinstance(plugin, l3_db.L3_NAT_dbonly_mixin):
             self.skipTest("Plugin is not L3_NAT_dbonly_mixin")
         ctx = context.Context('', 'foo')
@@ -3198,7 +3199,7 @@ class L3NatTestCaseBase(L3NatTestCaseMixin):
 
     def test_create_router_gateway_fails_nested_delete_router_failed(self):
         # Force _update_router_gw_info failure
-        plugin = directory.get_plugin(lib_constants.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
         if not isinstance(plugin, l3_db.L3_NAT_dbonly_mixin):
             self.skipTest("Plugin is not L3_NAT_dbonly_mixin")
         ctx = context.Context('', 'foo')
@@ -3235,7 +3236,7 @@ class L3NatTestCaseBase(L3NatTestCaseMixin):
 
     def test_router_add_interface_by_port_fails_nested(self):
         # Force _validate_router_port_info failure
-        plugin = directory.get_plugin(lib_constants.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
         if not isinstance(plugin, l3_db.L3_NAT_dbonly_mixin):
             self.skipTest("Plugin is not L3_NAT_dbonly_mixin")
         orig_update_port = self.plugin.update_port
@@ -3288,7 +3289,7 @@ class L3NatTestCaseBase(L3NatTestCaseMixin):
         """Test to make sure notification to routers occurs when the gateway
             ip address of a subnet of the external network is changed.
         """
-        plugin = directory.get_plugin(lib_constants.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
         if not hasattr(plugin, 'l3_rpc_notifier'):
             self.skipTest("Plugin does not support l3_rpc_notifier")
         # make sure the callback is registered.
@@ -3320,7 +3321,7 @@ class L3NatTestCaseBase(L3NatTestCaseMixin):
                                                       ['fake_device'], None)
 
     def test__notify_subnetpool_address_scope_update(self):
-        plugin = directory.get_plugin(lib_constants.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
 
         tenant_id = _uuid()
         with mock.patch.object(
@@ -3350,7 +3351,7 @@ class L3NatTestCaseBase(L3NatTestCaseMixin):
             chk_method.assert_called_with(admin_ctx, [router['router']['id']])
 
     def test_janitor_clears_orphaned_floatingip_port(self):
-        plugin = directory.get_plugin(lib_constants.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
         with self.network() as n:
             # floating IP ports are initially created with a device ID of
             # PENDING and are updated after the floating IP is actually
@@ -3375,7 +3376,7 @@ class L3NatTestCaseBase(L3NatTestCaseMixin):
         # if a server dies after the floating IP is created but before it
         # updates the floating IP port device ID, the janitor will be
         # responsible for updating the device ID to the correct value.
-        plugin = directory.get_plugin(lib_constants.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
         with self.floatingip_with_assoc() as fip:
             fip_port = self._list('ports',
                query_params='device_owner=network:floatingip')['ports'][0]
@@ -3397,7 +3398,7 @@ class L3NatTestCaseBase(L3NatTestCaseMixin):
     def test_janitor_doesnt_delete_if_fixed_in_interim(self):
         # here we ensure that the janitor doesn't delete the port on the second
         # call if the conditions have been fixed
-        plugin = directory.get_plugin(lib_constants.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
         with self.network() as n:
             port_res = self._create_port(
                 self.fmt, n['network']['id'],
@@ -3533,7 +3534,7 @@ class L3AgentDbTestCaseBase(L3NatTestCaseMixin):
         l3_rpc_agent_api_str = (
             'neutron.api.rpc.agentnotifiers.l3_rpc_agent_api.L3AgentNotifyAPI')
         with mock.patch(l3_rpc_agent_api_str):
-            plugin = directory.get_plugin(lib_constants.L3)
+            plugin = directory.get_plugin(plugin_constants.L3)
             notifyApi = plugin.l3_rpc_notifier
             kargs = [item for item in args]
             kargs.append(notifyApi)
@@ -3701,7 +3702,7 @@ class L3NatDBIntAgentSchedulingTestCase(L3BaseForIntTests,
         self.adminContext = context.get_admin_context()
 
     def _assert_router_on_agent(self, router_id, agent_host):
-        plugin = directory.get_plugin(lib_constants.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
         agents = plugin.list_l3_agents_hosting_router(
             self.adminContext, router_id)['agents']
         self.assertEqual(1, len(agents))
@@ -3758,7 +3759,7 @@ class L3NatDBIntAgentSchedulingTestCase(L3BaseForIntTests,
             self._assert_router_on_agent(r['router']['id'], 'host2')
 
     def test_router_update_gateway_scheduling_not_supported(self):
-        plugin = directory.get_plugin(lib_constants.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
         mock.patch.object(plugin, 'router_supports_scheduling',
                           return_value=False).start()
         with self.router() as r:
@@ -3907,7 +3908,7 @@ class L3NatDBTestCaseMixin(object):
 
     def setUp(self):
         super(L3NatDBTestCaseMixin, self).setUp()
-        plugin = directory.get_plugin(lib_constants.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
         if not isinstance(plugin, l3_db.L3_NAT_dbonly_mixin):
             self.skipTest("Plugin is not L3_NAT_dbonly_mixin")
 
@@ -3916,7 +3917,7 @@ class L3NatDBTestCaseMixin(object):
         the exception is propagated.
         """
 
-        plugin = directory.get_plugin(lib_constants.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
         ctx = context.Context('', 'foo')
 
         class MyException(Exception):
@@ -3949,7 +3950,7 @@ class L3NatDBSepTestCase(L3BaseForSepTests, L3NatTestCaseBase,
     """Unit tests for a separate L3 routing service plugin."""
 
     def test_port_deletion_prevention_handles_missing_port(self):
-        pl = directory.get_plugin(lib_constants.L3)
+        pl = directory.get_plugin(plugin_constants.L3)
         self.assertIsNone(
             pl.prevent_l3_port_deletion(context.get_admin_context(), 'fakeid')
         )
diff --git a/neutron/tests/unit/extensions/test_providernet.py b/neutron/tests/unit/extensions/test_providernet.py
index 6c38332c18d..d2fcf62141b 100644
--- a/neutron/tests/unit/extensions/test_providernet.py
+++ b/neutron/tests/unit/extensions/test_providernet.py
@@ -15,8 +15,8 @@
 
 import mock
 from neutron_lib.api.definitions import provider_net
-from neutron_lib import constants
 from neutron_lib import context
+from neutron_lib.plugins import constants
 from neutron_lib.plugins import directory
 from oslo_config import cfg
 from oslo_utils import uuidutils
diff --git a/neutron/tests/unit/extensions/test_router_availability_zone.py b/neutron/tests/unit/extensions/test_router_availability_zone.py
index 3e57f390fe5..bc5df86c286 100644
--- a/neutron/tests/unit/extensions/test_router_availability_zone.py
+++ b/neutron/tests/unit/extensions/test_router_availability_zone.py
@@ -11,7 +11,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from neutron_lib import constants
+from neutron_lib.plugins import constants
 
 from neutron.db.availability_zone import router as router_az_db
 from neutron.db import common_db_mixin
diff --git a/neutron/tests/unit/notifiers/test_nova.py b/neutron/tests/unit/notifiers/test_nova.py
index 620b327f466..2f1c66fa9ae 100644
--- a/neutron/tests/unit/notifiers/test_nova.py
+++ b/neutron/tests/unit/notifiers/test_nova.py
@@ -17,6 +17,7 @@
 import mock
 from neutron_lib import constants as n_const
 from neutron_lib import exceptions as n_exc
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from novaclient import api_versions
 from novaclient import exceptions as nova_exceptions
@@ -44,7 +45,7 @@ class TestNovaNotify(base.BaseTestCase):
                         'id': port_id}
 
         self.nova_notifier = nova.Notifier()
-        directory.add_plugin(n_const.CORE, FakePlugin())
+        directory.add_plugin(plugin_constants.CORE, FakePlugin())
 
     def test_notify_port_status_all_values(self):
         states = [n_const.PORT_STATUS_ACTIVE, n_const.PORT_STATUS_DOWN,
diff --git a/neutron/tests/unit/plugins/ml2/base.py b/neutron/tests/unit/plugins/ml2/base.py
index c65a56758f1..0a7f7f5e3d1 100644
--- a/neutron/tests/unit/plugins/ml2/base.py
+++ b/neutron/tests/unit/plugins/ml2/base.py
@@ -12,7 +12,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from neutron_lib import constants
+from neutron_lib.plugins import constants
 from neutron_lib.plugins import directory
 
 from neutron.tests.unit.plugins.ml2 import test_plugin
diff --git a/neutron/tests/unit/plugins/ml2/drivers/l2pop/test_mech_driver.py b/neutron/tests/unit/plugins/ml2/drivers/l2pop/test_mech_driver.py
index 87acc64f8d2..def682a6341 100644
--- a/neutron/tests/unit/plugins/ml2/drivers/l2pop/test_mech_driver.py
+++ b/neutron/tests/unit/plugins/ml2/drivers/l2pop/test_mech_driver.py
@@ -20,6 +20,7 @@ from neutron_lib.api.definitions import provider_net as pnet
 from neutron_lib import constants
 from neutron_lib import context
 from neutron_lib import exceptions
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from oslo_serialization import jsonutils
 import testtools
@@ -279,7 +280,7 @@ class TestL2PopulationRpcTestCase(test_plugin.Ml2PluginV2TestCase):
         # is added on HOST4.
         # HOST4 should get flood entries for HOST1 and HOST2
         router = self._create_ha_router()
-        directory.add_plugin(constants.L3, self.plugin)
+        directory.add_plugin(plugin_constants.L3, self.plugin)
         with self.subnet(network=self._network, enable_dhcp=False) as snet:
             subnet = snet['subnet']
             port = self._add_router_interface(subnet, router, HOST)
@@ -312,7 +313,7 @@ class TestL2PopulationRpcTestCase(test_plugin.Ml2PluginV2TestCase):
         # Remove_fdb should carry flood entry of only HOST2 and not HOST
         router = self._create_ha_router()
 
-        directory.add_plugin(constants.L3, self.plugin)
+        directory.add_plugin(plugin_constants.L3, self.plugin)
         with self.subnet(network=self._network, enable_dhcp=False) as snet:
             host_arg = {portbindings.HOST_ID: HOST, 'admin_state_up': True}
             with self.port(subnet=snet,
@@ -345,7 +346,7 @@ class TestL2PopulationRpcTestCase(test_plugin.Ml2PluginV2TestCase):
         # Both HA agents should be notified to other agents.
         router = self._create_ha_router()
 
-        directory.add_plugin(constants.L3, self.plugin)
+        directory.add_plugin(plugin_constants.L3, self.plugin)
         with self.subnet(network=self._network, enable_dhcp=False) as snet:
             host_arg = {portbindings.HOST_ID: HOST_4, 'admin_state_up': True}
             with self.port(subnet=snet,
diff --git a/neutron/tests/unit/plugins/ml2/test_plugin.py b/neutron/tests/unit/plugins/ml2/test_plugin.py
index 2d553df50db..fcf373da519 100644
--- a/neutron/tests/unit/plugins/ml2/test_plugin.py
+++ b/neutron/tests/unit/plugins/ml2/test_plugin.py
@@ -29,6 +29,7 @@ from neutron_lib.callbacks import resources
 from neutron_lib import constants
 from neutron_lib import context
 from neutron_lib import exceptions as exc
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from neutron_lib.plugins.ml2 import api as driver_api
 from oslo_db import exception as db_exc
@@ -772,7 +773,7 @@ class TestMl2PortsV2(test_plugin.TestPortsV2, Ml2PluginV2TestCase):
                                'create_port_postcommit',
                                side_effect=ml2_exc.MechanismDriverError(
                                    method='create_port_postcommit')):
-            l3_plugin = directory.get_plugin(constants.L3)
+            l3_plugin = directory.get_plugin(plugin_constants.L3)
             data = {'router': {'name': 'router', 'admin_state_up': True,
                                'tenant_id': 'fake_tenant'}}
             r = l3_plugin.create_router(self.context, data)
@@ -789,7 +790,7 @@ class TestMl2PortsV2(test_plugin.TestPortsV2, Ml2PluginV2TestCase):
         with mock.patch.object(ml2_plugin.Ml2Plugin, '_bind_port_if_needed',
                                side_effect=ml2_exc.MechanismDriverError(
                                    method='_bind_port_if_needed')):
-            l3_plugin = directory.get_plugin(constants.L3)
+            l3_plugin = directory.get_plugin(plugin_constants.L3)
             data = {'router': {'name': 'router', 'admin_state_up': True,
                                'tenant_id': 'fake_tenant'}}
             r = l3_plugin.create_router(self.context, data)
@@ -918,7 +919,7 @@ class TestMl2PortsV2(test_plugin.TestPortsV2, Ml2PluginV2TestCase):
             ])
 
     def test_l3_cleanup_on_net_delete(self):
-        l3plugin = directory.get_plugin(constants.L3)
+        l3plugin = directory.get_plugin(plugin_constants.L3)
         kwargs = {'arg_list': (external_net.EXTERNAL,),
                   external_net.EXTERNAL: True}
         with self.network(**kwargs) as n:
@@ -1045,7 +1046,7 @@ class TestMl2PortsV2(test_plugin.TestPortsV2, Ml2PluginV2TestCase):
     def test_delete_port_no_notify_in_disassociate_floatingips(self):
         ctx = context.get_admin_context()
         plugin = directory.get_plugin()
-        l3plugin = directory.get_plugin(constants.L3)
+        l3plugin = directory.get_plugin(plugin_constants.L3)
         with self.port() as port,\
                 mock.patch.object(
                     l3plugin,
@@ -1101,7 +1102,7 @@ class TestMl2PortsV2(test_plugin.TestPortsV2, Ml2PluginV2TestCase):
 
     def test_disassociate_floatingips_do_notify_returns_nothing(self):
         ctx = context.get_admin_context()
-        l3plugin = directory.get_plugin(constants.L3)
+        l3plugin = directory.get_plugin(plugin_constants.L3)
         with self.port() as port:
 
             port_id = port['port']['id']
@@ -1248,7 +1249,7 @@ class TestMl2PortsV2WithL3(test_plugin.TestPortsV2, Ml2PluginV2TestCase):
         plugin = directory.get_plugin()
         # enable subscription for events
         l3_router_plugin.L3RouterPlugin()
-        l3plugin = directory.get_plugin(constants.L3)
+        l3plugin = directory.get_plugin(plugin_constants.L3)
         host_arg = {portbindings.HOST_ID: HOST}
         with mock.patch.object(l3plugin.l3_rpc_notifier,
                                'routers_updated_on_host') as mock_updated:
@@ -1454,7 +1455,7 @@ class TestMl2DvrPortsV2(TestMl2PortsV2):
             mock.PropertyMock(return_value=extensions))
 
     def test_delete_port_notifies_l3_plugin(self, floating_ip=False):
-        directory.add_plugin(constants.L3, self.l3plugin)
+        directory.add_plugin(plugin_constants.L3, self.l3plugin)
         ns_to_delete = {'host': 'myhost', 'agent_id': 'vm_l3_agent',
                         'router_id': 'my_router'}
         router_ids = set()
@@ -1484,7 +1485,7 @@ class TestMl2DvrPortsV2(TestMl2PortsV2):
         self.test_delete_port_notifies_l3_plugin(floating_ip=True)
 
     def test_concurrent_csnat_port_delete(self):
-        plugin = directory.get_plugin(constants.L3)
+        plugin = directory.get_plugin(plugin_constants.L3)
         r = plugin.create_router(
             self.context,
             {'router': {'name': 'router', 'admin_state_up': True,
diff --git a/neutron/tests/unit/plugins/ml2/test_rpc.py b/neutron/tests/unit/plugins/ml2/test_rpc.py
index 76fd15f1bde..57740a85d04 100644
--- a/neutron/tests/unit/plugins/ml2/test_rpc.py
+++ b/neutron/tests/unit/plugins/ml2/test_rpc.py
@@ -22,6 +22,7 @@ import collections
 import mock
 from neutron_lib.callbacks import resources
 from neutron_lib import constants
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from oslo_config import cfg
 from oslo_context import context as oslo_context
@@ -49,7 +50,7 @@ class RpcCallbacksTestCase(base.BaseTestCase):
         self.callbacks = plugin_rpc.RpcCallbacks(self.notifier,
                                                  self.type_manager)
         self.plugin = mock.MagicMock()
-        directory.add_plugin(constants.CORE, self.plugin)
+        directory.add_plugin(plugin_constants.CORE, self.plugin)
 
     def _test_update_device_up(self, host=None):
         kwargs = {
diff --git a/neutron/tests/unit/scheduler/test_l3_agent_scheduler.py b/neutron/tests/unit/scheduler/test_l3_agent_scheduler.py
index 015ff3b6de2..06993c1de49 100644
--- a/neutron/tests/unit/scheduler/test_l3_agent_scheduler.py
+++ b/neutron/tests/unit/scheduler/test_l3_agent_scheduler.py
@@ -21,6 +21,7 @@ import mock
 from neutron_lib.api.definitions import portbindings
 from neutron_lib import constants
 from neutron_lib import context as n_context
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from oslo_config import cfg
 from oslo_utils import importutils
@@ -828,7 +829,7 @@ class L3DvrSchedulerTestCase(testlib_api.SqlTestCase):
         port = kwargs.get('original_port')
         port_addr_pairs = port['allowed_address_pairs']
         l3plugin = mock.Mock()
-        directory.add_plugin(constants.L3, l3plugin)
+        directory.add_plugin(plugin_constants.L3, l3plugin)
         l3_dvrscheduler_db._notify_l3_agent_port_update(
             'port', 'after_update', mock.ANY, **kwargs)
         l3plugin._get_allowed_address_pair_fixed_ips.return_value = (
@@ -875,7 +876,7 @@ class L3DvrSchedulerTestCase(testlib_api.SqlTestCase):
         port = kwargs.get('port')
         port_addr_pairs = port['allowed_address_pairs']
         l3plugin = mock.Mock()
-        directory.add_plugin(constants.L3, l3plugin)
+        directory.add_plugin(plugin_constants.L3, l3plugin)
         l3_dvrscheduler_db._notify_l3_agent_port_update(
             'port', 'after_update', mock.ANY, **kwargs)
         self.assertTrue(
@@ -911,7 +912,7 @@ class L3DvrSchedulerTestCase(testlib_api.SqlTestCase):
             'router', constants.L3_AGENT_SCHEDULER_EXT_ALIAS,
             constants.L3_DISTRIBUTED_EXT_ALIAS
         ]
-        directory.add_plugin(constants.L3, l3plugin)
+        directory.add_plugin(plugin_constants.L3, l3plugin)
         l3_dvrscheduler_db._notify_l3_agent_port_update(
             'port', 'after_update', plugin, **kwargs)
         self.assertFalse(
@@ -930,7 +931,7 @@ class L3DvrSchedulerTestCase(testlib_api.SqlTestCase):
             },
         }
         l3plugin = mock.Mock()
-        directory.add_plugin(constants.L3, l3plugin)
+        directory.add_plugin(plugin_constants.L3, l3plugin)
         l3_dvrscheduler_db._notify_l3_agent_new_port(
             'port', 'after_create', mock.ANY, **kwargs)
         l3plugin.update_arp_entry_for_dvr_service_port.\
@@ -948,7 +949,7 @@ class L3DvrSchedulerTestCase(testlib_api.SqlTestCase):
             }
         }
         l3plugin = mock.Mock()
-        directory.add_plugin(constants.L3, l3plugin)
+        directory.add_plugin(plugin_constants.L3, l3plugin)
         l3_dvrscheduler_db._notify_l3_agent_new_port(
             'port', 'after_create', mock.ANY, **kwargs)
         self.assertFalse(
@@ -970,7 +971,7 @@ class L3DvrSchedulerTestCase(testlib_api.SqlTestCase):
             },
         }
         l3plugin = mock.Mock()
-        directory.add_plugin(constants.L3, l3plugin)
+        directory.add_plugin(plugin_constants.L3, l3plugin)
         l3_dvrscheduler_db._notify_l3_agent_port_update(
             'port', 'after_update', mock.ANY, **kwargs)
         l3plugin.dvr_handle_new_service_port.assert_called_once_with(
@@ -992,7 +993,7 @@ class L3DvrSchedulerTestCase(testlib_api.SqlTestCase):
             },
         }
         l3plugin = mock.Mock()
-        directory.add_plugin(constants.L3, l3plugin)
+        directory.add_plugin(plugin_constants.L3, l3plugin)
         l3_dvrscheduler_db._notify_l3_agent_port_update(
             'port', 'after_update', mock.ANY, **kwargs)
 
@@ -1017,7 +1018,7 @@ class L3DvrSchedulerTestCase(testlib_api.SqlTestCase):
             'mac_address_updated': True
         }
         l3plugin = mock.Mock()
-        directory.add_plugin(constants.L3, l3plugin)
+        directory.add_plugin(plugin_constants.L3, l3plugin)
         l3_dvrscheduler_db._notify_l3_agent_port_update(
             'port', 'after_update', mock.ANY, **kwargs)
 
@@ -1063,7 +1064,7 @@ class L3DvrSchedulerTestCase(testlib_api.SqlTestCase):
             },
         }
         l3plugin = mock.Mock()
-        directory.add_plugin(constants.L3, l3plugin)
+        directory.add_plugin(plugin_constants.L3, l3plugin)
         with mock.patch.object(l3plugin, 'get_dvr_routers_to_remove',
                                return_value=routers_to_remove),\
                 mock.patch.object(l3plugin, '_get_floatingips_by_port_id',
@@ -1110,7 +1111,7 @@ class L3DvrSchedulerTestCase(testlib_api.SqlTestCase):
             'router', constants.L3_AGENT_SCHEDULER_EXT_ALIAS,
             constants.L3_DISTRIBUTED_EXT_ALIAS
         ]
-        directory.add_plugin(constants.L3, l3plugin)
+        directory.add_plugin(plugin_constants.L3, l3plugin)
         with mock.patch.object(l3plugin, 'get_dvr_routers_to_remove',
                                return_value=[{'agent_id': 'foo_agent',
                                               'router_id': 'foo_id',
@@ -1138,7 +1139,7 @@ class L3DvrSchedulerTestCase(testlib_api.SqlTestCase):
             'router', constants.L3_AGENT_SCHEDULER_EXT_ALIAS,
             constants.L3_DISTRIBUTED_EXT_ALIAS
         ]
-        directory.add_plugin(constants.L3, l3plugin)
+        directory.add_plugin(plugin_constants.L3, l3plugin)
         port = {
                 'id': uuidutils.generate_uuid(),
                 'device_id': 'abcd',
@@ -1314,7 +1315,7 @@ class L3HAPlugin(db_v2.NeutronDbPluginV2,
 
     @classmethod
     def get_plugin_type(cls):
-        return constants.L3
+        return plugin_constants.L3
 
     def get_plugin_description(self):
         return "L3 Routing Service Plugin for testing"
@@ -1337,7 +1338,7 @@ class L3HATestCaseMixin(testlib_api.SqlTestCase,
         cfg.CONF.set_override('max_l3_agents_per_router', 0)
 
         manager.init()
-        self.plugin = directory.get_plugin(constants.L3)
+        self.plugin = directory.get_plugin(plugin_constants.L3)
         self.plugin.router_scheduler = importutils.import_object(
             'neutron.scheduler.l3_agent_scheduler.ChanceScheduler'
         )
diff --git a/neutron/tests/unit/services/revisions/test_revision_plugin.py b/neutron/tests/unit/services/revisions/test_revision_plugin.py
index ff9699834d7..92db6ae9b9b 100644
--- a/neutron/tests/unit/services/revisions/test_revision_plugin.py
+++ b/neutron/tests/unit/services/revisions/test_revision_plugin.py
@@ -14,8 +14,8 @@
 #
 
 import netaddr
-from neutron_lib import constants
 from neutron_lib import context as nctx
+from neutron_lib.plugins import constants
 from neutron_lib.plugins import directory
 from oslo_utils import uuidutils
 
diff --git a/neutron/tests/unit/test_manager.py b/neutron/tests/unit/test_manager.py
index 0ecaf160cc8..99e916a8928 100644
--- a/neutron/tests/unit/test_manager.py
+++ b/neutron/tests/unit/test_manager.py
@@ -16,7 +16,7 @@
 import weakref
 
 import fixtures
-from neutron_lib import constants as lib_const
+from neutron_lib.plugins import constants as lib_const
 from neutron_lib.plugins import directory
 from oslo_config import cfg
 
diff --git a/neutron/tests/unit/test_policy.py b/neutron/tests/unit/test_policy.py
index 1baac228170..311701cf151 100644
--- a/neutron/tests/unit/test_policy.py
+++ b/neutron/tests/unit/test_policy.py
@@ -19,6 +19,7 @@ import mock
 from neutron_lib import constants
 from neutron_lib import context
 from neutron_lib import exceptions
+from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from oslo_config import cfg
 from oslo_db import exception as db_exc
@@ -222,7 +223,7 @@ class NeutronPolicyTestCase(base.BaseTestCase):
         self.context = context.Context('fake', 'fake', roles=['user'])
         plugin_klass = importutils.import_class(
             "neutron.db.db_base_plugin_v2.NeutronDbPluginV2")
-        directory.add_plugin(constants.CORE, plugin_klass())
+        directory.add_plugin(plugin_constants.CORE, plugin_klass())
 
     def _set_rules(self, **kwargs):
         rules_dict = {