Comment 14 for bug 1230407

To add more context, the gate-tempest-devstack-neutron is showing two failure modes:
1) behaviour which is exactly about this bug - as it can be seen in http://logs.openstack.org/91/48591/2/gate/gate-tempest-devstack-vm-neutron/4e2582a/ - In this case the timeout, being caused by agent RPC calls, can happen at anytime - not just a VM boot, and indeed we have failures in tempest.api.network tests
2) behaviour without any related traceback in neutron (the ones I see are related to negative tests IMHO), as it can be seen in http://logs.openstack.org/46/47546/2/gate/gate-tempest-devstack-vm-neutron/c8da791/

Hopeefully removing vpn from the gate will reduce the occurency of #1; however I am more concerned about manifestations of type #2, since they are more frequent in the tests I have been doing on my machines.