Refreshing in memory similar problem with Nova-Docker Driver (Kilo) with which I had same kind of problems (VXLAN connection Controller <==> Compute) on F22 (OVS 2.4.0) when the same driver worked fine on CentOS 7.1 (OVS 2.3.1). I just guess that Nova-Docker driver has a problem with OVS 2.4.0 no matter of stable/kilo, stable/liberty, stable/mitaka branches been checked out for driver build.
I have to notice that issue is related specifically with ML2&OVS&VXLAN setup, RDO Mitaka deployment ML2&OVS&VLAN works with Nova-Docker (stable/mitaka) with no problems.
I have not run ovs-ofctl dump-flows at br-tun bridges and etc,because even having proved malfunctinality I cannot file it to BZ.Nova-Docker Driver is not packaged for RDO so it’s upstream stuff.Upstream won’t consider issue which involves build driver from source on RDO Mitaka (RC1).
Thus as quick and efficient workaround I suggest DVR deployment setup.It will result South-North traffic to be forwarded right away from host running Docker Hypervisor to Internet and vice/versa due to basic “fg” functionality ( outgoing interface of fip-namespace,residing on Compute node having L3 agent running in “dvr” agent_mode ).
Complete text maybe seen http://bderzhavets.blogspot.com/2016/04/ha-for-glance-storage-of-docker.html