diff --git a/tempest/api/network/test_vpnaas_extensions.py b/tempest/api/network/test_vpnaas_extensions.py
index 7905b97..63a8e24 100644
--- a/tempest/api/network/test_vpnaas_extensions.py
+++ b/tempest/api/network/test_vpnaas_extensions.py
@@ -40,7 +40,9 @@
         super(VPNaaSJSON, cls).setUpClass()
         cls.network = cls.create_network()
         cls.subnet = cls.create_subnet(cls.network)
-        cls.router = cls.create_router(data_utils.rand_name("router-"))
+        cls.router = cls.create_router(
+            data_utils.rand_name("router-"),
+            external_network_id=cls.network_cfg.public_network_id)
         cls.create_router_interface(cls.router['id'], cls.subnet['id'])
         cls.vpnservice = cls.create_vpnservice(cls.subnet['id'],
                                                cls.router['id'])