diff --git a/neutron/db/external_net_db.py b/neutron/db/external_net_db.py
index 98c7b1171e7..70f4f47e9ae 100644
--- a/neutron/db/external_net_db.py
+++ b/neutron/db/external_net_db.py
@@ -45,12 +45,6 @@ _deprecate._moved_global('ExternalNetwork', new_module=ext_net_models)
 class External_net_db_mixin(object):
     """Mixin class to add external network methods to db_base_plugin_v2."""
 
-    def _network_model_hook(self, context, original_model, query):
-        query = query.outerjoin(ext_net_models.ExternalNetwork,
-                                (original_model.id ==
-                                 ext_net_models.ExternalNetwork.network_id))
-        return query
-
     @staticmethod
     def _network_filter_hook(context, original_model, conditions):
         if conditions is not None and not hasattr(conditions, '__iter__'):
@@ -73,10 +67,8 @@ class External_net_db_mixin(object):
         if not vals:
             return query
         if vals[0]:
-            return query.filter(
-                ext_net_models.ExternalNetwork.network_id != expr.null())
-        return query.filter(
-            ext_net_models.ExternalNetwork.network_id == expr.null())
+            return query.filter(models_v2.Network.external.has())
+        return query.filter(~models_v2.Network.external.has())
 
     # TODO(salvatore-orlando): Perform this operation without explicitly
     # referring to db_base_plugin_v2, as plugins that do not extend from it
@@ -84,7 +76,7 @@ class External_net_db_mixin(object):
     db_base_plugin_v2.NeutronDbPluginV2.register_model_query_hook(
         models_v2.Network,
         "external_net",
-        '_network_model_hook',
+        None,
         '_network_filter_hook',
         '_network_result_filter_hook')