The os-interface (v2) and os-attach-interfaces (v3) APIs are only used for the neutron network API, you'll get a NotImplemented if trying to call the related methods with nova-network [1]. Since we aren't proxying to neutron in the v3 API (v2.1), why does os-attach-interfaces [2] exist? Was this just an oversight? If so, please allow me to delete it. :) [1] http://git.openstack.org/cgit/openstack/nova/tree/nova/network/api.py?id=2014.2.rc1#n310 [2] http://git.openstack.org/cgit/openstack/nova/tree/nova/api/openstack/compute/plugins/v3/attach_interfaces.py?id=2014.2.rc1 -- Thanks, Matt Riedemann