Comment 5 for bug 1961011

@Slawek, yes, that's right, gateway port is not needed anymore. For (VM) port, it has IPv6 addresses from subnets, the controller will send each subnet's infos to it. Then the rest work will be the configuration of the OS (Linux/windows) or users' choices.

@Brian, I never try such configurations for interacting the neutron router and physical router. But I can image an solution is that RS maybe can be implemented as a RS_Responder on network nodes, something like ARP responder, when the router setup external gateway and internal interface, add related RS_Responder flows to the ovs-bridge. If the native ovs-flows can not do that work, send the RS to ovs-agent, let the controller response that.