diff --git a/tempest/api/compute/servers/test_attach_interfaces.py b/tempest/api/compute/servers/test_attach_interfaces.py
index efecd6c..9fa2d08 100644
--- a/tempest/api/compute/servers/test_attach_interfaces.py
+++ b/tempest/api/compute/servers/test_attach_interfaces.py
@@ -109,21 +109,24 @@
         """
         port = self.ports_client.show_port(port_id)['port']
         device_id = port['device_id']
+        dns_name = port.get('dns_name')
         start = int(time.time())
 
         # NOTE(mriedem): Nova updates the port's device_id to '' rather than
         # None, but it's not contractual so handle Falsey either way.
-        while device_id:
+        while any([device_id, dns_name]):
             time.sleep(self.build_interval)
             port = self.ports_client.show_port(port_id)['port']
             device_id = port['device_id']
+            dns_name = port.get('dns_name')
 
             timed_out = int(time.time()) - start >= self.build_timeout
 
-            if device_id and timed_out:
-                message = ('Port %s failed to detach (device_id %s) within '
-                           'the required time (%s s).' %
-                           (port_id, device_id, self.build_timeout))
+            if any([device_id, dns_name]) and timed_out:
+                message = ('Port %s failed to detach (device_id %s), '
+                           '(dns_name %s) within the required time (%s s).' %
+                           (port_id, device_id or 'is out',
+                            dns_name or 'is out', self.build_timeout))
                 raise lib_exc.TimeoutException(message)
 
         return port