Comment 1 for bug 1574631

from Duan Kebo:
@yuli, the router namespace is deleted due to l3 agent's rpc call doesn't processed by neutron l3 plugin. Because we have used dragonflow as core plugin, we can't use l3 service plugin. In order to used it, you must use ml2 as core plugin. Dragonflow will support ML2 in the next release.