diff --git a/neutron/plugins/ml2/drivers/type_tunnel.py b/neutron/plugins/ml2/drivers/type_tunnel.py
index 65f85fad0f5..f292458b88a 100644
--- a/neutron/plugins/ml2/drivers/type_tunnel.py
+++ b/neutron/plugins/ml2/drivers/type_tunnel.py
@@ -563,7 +563,11 @@ class TunnelRpcCallbackMixin(object):
             # Return the list of tunnels IP's to the agent
             return entry
         else:
-            msg = _("Network type value '%s' not supported") % tunnel_type
+            msg = (_("Network type value %(type)s not supported, "
+                    "host: %(host)s with tunnel IP: %(ip)s") %
+                    {'type': tunnel_type,
+                     'host': host or 'legacy mode (no host provided by agent)',
+                     'ip': tunnel_ip})
             raise exc.InvalidInput(error_message=msg)