diff --git a/neutron/extensions/l3.py b/neutron/extensions/l3.py
index 78eeade0747..a0795a393d9 100644
--- a/neutron/extensions/l3.py
+++ b/neutron/extensions/l3.py
@@ -17,6 +17,7 @@ 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
 import six
@@ -24,7 +25,6 @@ import six
 from neutron._i18n import _
 from neutron.api.v2 import resource_helper
 from neutron.conf import quota
-from neutron.plugins.common import constants
 
 
 # L3 Exceptions
@@ -195,7 +195,7 @@ class L3(extensions.ExtensionDescriptor):
                                  'remove_router_interface': 'PUT'}}
         return resource_helper.build_resource_info(plural_mappings,
                                                    RESOURCE_ATTRIBUTE_MAP,
-                                                   constants.L3_ROUTER_NAT,
+                                                   constants.L3,
                                                    action_map=action_map,
                                                    register_quota=True)
 
diff --git a/neutron/plugins/common/constants.py b/neutron/plugins/common/constants.py
index 23f8dc5c86c..a8524bd7bdd 100644
--- a/neutron/plugins/common/constants.py
+++ b/neutron/plugins/common/constants.py
@@ -13,6 +13,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from neutron_lib import constants
+
+
 # Neutron well-known service type constants:
 DUMMY = "DUMMY"
 LOADBALANCER = "LOADBALANCER"
@@ -20,7 +23,6 @@ LOADBALANCERV2 = "LOADBALANCERV2"
 FIREWALL = "FIREWALL"
 VPN = "VPN"
 METERING = "METERING"
-L3_ROUTER_NAT = "L3_ROUTER_NAT"
 FLAVORS = "FLAVORS"
 QOS = "QOS"
 
@@ -33,7 +35,7 @@ EXT_TO_SERVICE_MAPPING = {
     'fwaas': FIREWALL,
     'vpnaas': VPN,
     'metering': METERING,
-    'router': L3_ROUTER_NAT,
+    'router': constants.L3,
     'qos': QOS,
 }
 
diff --git a/neutron/services/l3_router/l3_router_plugin.py b/neutron/services/l3_router/l3_router_plugin.py
index 2a3c585734c..9ed3ee9ec81 100644
--- a/neutron/services/l3_router/l3_router_plugin.py
+++ b/neutron/services/l3_router/l3_router_plugin.py
@@ -32,7 +32,6 @@ from neutron.db import l3_hamode_db
 from neutron.db import l3_hascheduler_db
 from neutron.db.models import l3 as l3_models
 from neutron.extensions import l3
-from neutron.plugins.common import constants
 from neutron.quota import resource_registry
 from neutron import service
 from neutron.services.l3_router.service_providers import driver_controller
@@ -95,7 +94,7 @@ class L3RouterPlugin(service_base.ServicePluginBase,
 
     @classmethod
     def get_plugin_type(cls):
-        return constants.L3_ROUTER_NAT
+        return n_const.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 9dcb14d9c73..df35231d4b7 100644
--- a/neutron/services/l3_router/service_providers/driver_controller.py
+++ b/neutron/services/l3_router/service_providers/driver_controller.py
@@ -45,7 +45,7 @@ class DriverController(object):
         self.l3_plugin = l3_plugin
         self._stm = st_db.ServiceTypeManager.get_instance()
         self._stm.add_provider_configuration(
-                constants.L3_ROUTER_NAT, _LegacyPlusProviderConfiguration())
+                lib_const.L3, _LegacyPlusProviderConfiguration())
         self._load_drivers()
         registry.subscribe(self._check_router_request,
                            resources.ROUTER, events.BEFORE_CREATE)
@@ -58,7 +58,7 @@ class DriverController(object):
 
     def _load_drivers(self):
         self.drivers, self.default_provider = (
-            service_base.load_drivers(constants.L3_ROUTER_NAT, self.l3_plugin))
+            service_base.load_drivers(lib_const.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)
@@ -86,7 +86,7 @@ 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, 'L3_ROUTER_NAT',
+        self._stm.add_resource_association(context, lib_const.L3,
                                            drv.name, router['id'])
 
     def _clear_router_provider(self, resource, event, trigger, context,
@@ -143,7 +143,7 @@ class DriverController(object):
             with context.session.begin(subtransactions=True):
                 self._stm.del_resource_associations(context, [router_id])
                 self._stm.add_resource_association(
-                    context, 'L3_ROUTER_NAT', new_drv.name, router_id)
+                    context, lib_const.L3, new_drv.name, router_id)
 
     def _get_provider_for_router(self, context, router_id):
         """Return the provider driver handle for a router id."""
@@ -155,7 +155,7 @@ 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, 'L3_ROUTER_NAT',
+            self._stm.add_resource_association(context, lib_const.L3,
                                                driver_name, router_id)
         return self.drivers[driver_name]
 
@@ -211,7 +211,7 @@ class _LegacyPlusProviderConfiguration(
                              ('single_node', 'single_node.SingleNodeDriver')):
             path = 'neutron.services.l3_router.service_providers.%s' % driver
             try:
-                self.add_provider({'service_type': constants.L3_ROUTER_NAT,
+                self.add_provider({'service_type': lib_const.L3,
                                    'name': name, 'driver': path,
                                    'default': False})
             except lib_exc.Invalid:
diff --git a/neutron/tests/tempest/api/admin/test_routers_flavors.py b/neutron/tests/tempest/api/admin/test_routers_flavors.py
index 4988ba80b5e..7323427cb7d 100644
--- a/neutron/tests/tempest/api/admin/test_routers_flavors.py
+++ b/neutron/tests/tempest/api/admin/test_routers_flavors.py
@@ -11,6 +11,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from neutron_lib import constants
 from tempest.lib import exceptions as lib_exc
 from tempest import test
 import testtools
@@ -45,7 +46,7 @@ class RoutersFlavorTestCase(base.BaseRouterTest):
         cls.flavor = cls.create_flavor(
                 name='special_flavor',
                 description='econonomy class',
-                service_type='L3_ROUTER_NAT')
+                service_type=constants.L3)
         cls.admin_client.create_flavor_service_profile(
             cls.flavor['id'], sp['service_profile']['id'])
         cls.flavor_service_profiles.append((cls.flavor['id'],
@@ -63,7 +64,7 @@ class RoutersFlavorTestCase(base.BaseRouterTest):
         cls.prem_flavor = cls.create_flavor(
                 name='better_special_flavor',
                 description='econonomy comfort',
-                service_type='L3_ROUTER_NAT')
+                service_type=constants.L3)
         cls.admin_client.create_flavor_service_profile(
             cls.prem_flavor['id'], sp['service_profile']['id'])
         cls.flavor_service_profiles.append((cls.prem_flavor['id'],
diff --git a/neutron/tests/unit/agent/l3/test_agent.py b/neutron/tests/unit/agent/l3/test_agent.py
index 402150fba69..131b7d88d71 100644
--- a/neutron/tests/unit/agent/l3/test_agent.py
+++ b/neutron/tests/unit/agent/l3/test_agent.py
@@ -53,7 +53,6 @@ from neutron.conf.agent.l3 import config as l3_config
 from neutron.conf.agent.l3 import ha as ha_conf
 from neutron.conf import common as base_config
 from neutron.extensions import portbindings
-from neutron.plugins.common import constants as p_const
 from neutron.tests import base
 from neutron.tests.common import l3_test_common
 
@@ -2281,7 +2280,7 @@ class TestBasicRouterOperations(BasicRouterOperationsFramework):
             self.assertEqual(2, mocked_func.call_count)
 
     def test_get_service_plugin_list(self):
-        service_plugins = [p_const.L3_ROUTER_NAT]
+        service_plugins = [lib_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/extensions/test_external_net.py b/neutron/tests/unit/extensions/test_external_net.py
index aa8a49e9c90..43c80553326 100644
--- a/neutron/tests/unit/extensions/test_external_net.py
+++ b/neutron/tests/unit/extensions/test_external_net.py
@@ -185,7 +185,7 @@ class ExtNetDBTestCase(test_db_base_plugin_v2.NeutronDbPluginV2TestCase):
 
     def test_delete_network_check_disassociated_floatingips(self):
         l3_mock = mock.Mock()
-        directory.add_plugin('L3_ROUTER_NAT', l3_mock)
+        directory.add_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 8560ffeb223..9034dc641aa 100644
--- a/neutron/tests/unit/extensions/test_l3.py
+++ b/neutron/tests/unit/extensions/test_l3.py
@@ -52,7 +52,6 @@ from neutron.extensions import dns
 from neutron.extensions import external_net
 from neutron.extensions import l3
 from neutron.extensions import portbindings
-from neutron.plugins.common import constants as service_constants
 from neutron.plugins.ml2 import config
 from neutron.tests import base
 from neutron.tests.common import helpers
@@ -307,7 +306,7 @@ class TestL3NatServicePlugin(common_db_mixin.CommonDbMixin,
 
     @classmethod
     def get_plugin_type(cls):
-        return service_constants.L3_ROUTER_NAT
+        return lib_constants.L3
 
     def get_plugin_description(self):
         return "L3 Routing Service Plugin for testing"
diff --git a/neutron/tests/unit/extensions/test_router_availability_zone.py b/neutron/tests/unit/extensions/test_router_availability_zone.py
index 30e6e8b9d04..9319309151b 100644
--- a/neutron/tests/unit/extensions/test_router_availability_zone.py
+++ b/neutron/tests/unit/extensions/test_router_availability_zone.py
@@ -11,6 +11,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from neutron_lib import constants
 import six
 
 from neutron.db.availability_zone import router as router_az_db
@@ -19,7 +20,6 @@ from neutron.db import l3_agentschedulers_db
 from neutron.db import l3_db
 from neutron.extensions import l3
 from neutron.extensions import router_availability_zone as router_az
-from neutron.plugins.common import constants as service_constants
 from neutron.tests.unit.extensions import test_availability_zone as test_az
 from neutron.tests.unit.extensions import test_l3
 
@@ -40,7 +40,7 @@ class AZRouterTestPlugin(common_db_mixin.CommonDbMixin,
 
     @classmethod
     def get_plugin_type(cls):
-        return service_constants.L3_ROUTER_NAT
+        return constants.L3
 
     def get_plugin_description(self):
         return "L3 Routing Service Plugin for testing"
diff --git a/neutron/tests/unit/scheduler/test_l3_agent_scheduler.py b/neutron/tests/unit/scheduler/test_l3_agent_scheduler.py
index 56b89133de7..8cce97b2cfa 100644
--- a/neutron/tests/unit/scheduler/test_l3_agent_scheduler.py
+++ b/neutron/tests/unit/scheduler/test_l3_agent_scheduler.py
@@ -43,7 +43,6 @@ from neutron.extensions import l3_ext_ha_mode as l3_ha
 from neutron.extensions import l3agentscheduler as l3agent
 from neutron.extensions import portbindings
 from neutron import manager
-from neutron.plugins.common import constants as service_constants
 from neutron.scheduler import l3_agent_scheduler
 from neutron.tests import base
 from neutron.tests.common import helpers
@@ -1415,7 +1414,7 @@ class L3HAPlugin(db_v2.NeutronDbPluginV2,
 
     @classmethod
     def get_plugin_type(cls):
-        return service_constants.L3_ROUTER_NAT
+        return constants.L3
 
     def get_plugin_description(self):
         return "L3 Routing Service Plugin for testing"