diff --git a/neutron/db/db_base_plugin_v2.py b/neutron/db/db_base_plugin_v2.py
index 0f2074c7b75..d734918692f 100644
--- a/neutron/db/db_base_plugin_v2.py
+++ b/neutron/db/db_base_plugin_v2.py
@@ -435,7 +435,12 @@ class NeutronDbPluginV2(db_base_plugin_common.DbBasePluginCommon,
                 models_v2.Port.id).filter_by(network_id=id).filter(
                 models_v2.Port.device_owner.in_(AUTO_DELETE_PORT_OWNERS))]
         for port_id in auto_delete_port_ids:
-            self.delete_port(context.elevated(), port_id)
+            try:
+                self.delete_port(context.elevated(), port_id)
+            except exc.PortNotFound:
+                # Don't raise if something else concurrently deleted the port
+                LOG.debug("Ignoring PortNotFound when deleting port '%s'. "
+                          "The port has already been deleted.", port_id)
         # clean up subnets
         subnets = self._get_subnets_by_network(context, id)
         with db_api.exc_to_retry(os_db_exc.DBReferenceError):
diff --git a/neutron/tests/unit/db/test_db_base_plugin_v2.py b/neutron/tests/unit/db/test_db_base_plugin_v2.py
index bd9e2573597..d9db78bb697 100644
--- a/neutron/tests/unit/db/test_db_base_plugin_v2.py
+++ b/neutron/tests/unit/db/test_db_base_plugin_v2.py
@@ -1581,6 +1581,36 @@ fixed_ips=ip_address%%3D%s&fixed_ips=ip_address%%3D%s&fixed_ips=subnet_id%%3D%s
         res = req.get_response(self.api)
         self.assertEqual(webob.exc.HTTPNoContent.code, res.status_int)
 
+    def test_delete_network_port_exists_owned_by_network_port_not_found(self):
+        """Tests that we continue to gracefully delete the network even if
+        a neutron:dhcp-owned port was deleted concurrently.
+        """
+        res = self._create_network(fmt=self.fmt, name='net',
+                                   admin_state_up=True)
+        network = self.deserialize(self.fmt, res)
+        network_id = network['network']['id']
+        self._create_port(self.fmt, network_id,
+                          device_owner=constants.DEVICE_OWNER_DHCP)
+        # Raise PortNotFound when trying to delete the port to simulate a
+        # concurrent delete race; note that we actually have to delete the port
+        # "out of band" otherwise deleting the network will fail because of
+        # constraints in the data model.
+        plugin = directory.get_plugin()
+        orig_delete = plugin.delete_port
+
+        def fake_delete_port(context, id):
+            # Delete the port for real from the database and then raise
+            # PortNotFound to simulate the race.
+            self.assertIsNone(orig_delete(context, id))
+            raise lib_exc.PortNotFound(port_id=id)
+
+        p = mock.patch.object(plugin, 'delete_port')
+        mock_del_port = p.start()
+        mock_del_port.side_effect = fake_delete_port
+        req = self.new_delete_request('networks', network_id)
+        res = req.get_response(self.api)
+        self.assertEqual(webob.exc.HTTPNoContent.code, res.status_int)
+
     def test_update_port_delete_ip(self):
         with self.subnet() as subnet:
             with self.port(subnet=subnet) as port: