Refer to my latest post here: https://visualne.wordpress.com/ It will finally explain how this works at a high level.
Forget what I said in the last post about dnsmasq interfaces and gateways and vms being in the right vlan. I have the dnsmasq interface as well as the gateway address for the subnet in a completely different vlan then any interface dealing with the vm on the compute node. Refer to the output below.
^The .2 address serves up ip addresses on the 192.168.19.0/24 subnet.^ The .1 address is the gateway for the subnet.
Notice how in the above screenshot, both of those interface are in vlan 5.
The screenshot below is all ports attached to the OVS on the compute node. NONE of them are in vlan 5, yet if I ping 192.168.19.2 from the vm on the compute node. And that VM is in vlan 4. I can still ping 192.168.19.2, and that interface is in vlan 5.