It looks like the latest manifestation of this bug is:
http://logs.openstack.org/42/90442/7/check/check-grenade-dsvm-neutron/cad7b84/logs/new/screen-q-vpn.txt.gz
2014-04-29 21:48:09.872 24709 ERROR neutron.agent.l3_agent [-] An interface driver must be specified
It looks like the latest manifestation of this bug is:
http:// logs.openstack. org/42/ 90442/7/ check/check- grenade- dsvm-neutron/ cad7b84/ logs/new/ screen- q-vpn.txt. gz
2014-04-29 21:48:09.872 24709 ERROR neutron. agent.l3_ agent [-] An interface driver must be specified