[ovn] FIP not working when mixing vlan and geneve tenant networks

[Luis Tomas]

The flag redirect-type=bridge can only be used when there is no mix of geneve and vlan networks in the same router, as handled here [1].

When there is such a mix, the flag reside-on-redirect-chassis is being used, but it is not working for all cases:
- Either you centralize the traffic and you make it work for VM with FIPs (also meaning no DVR)
- Or you distribute the traffic and make it work for VMs without FIPs (enabling DVR but breaking traffic for VMs with FIPs as SNAT is not perform on the traffic out)

Due to this, we should block the option to mix geneve and vlan networks in the same router so that the "redirect-type=bridge" can be used and we can have DVR + vlan tenant networks + NATing

[1] https://bugs.launchpad.net/neutron/+bug/2012712

[2] https://issues.redhat.com/browse/FDP-209

[Slawek Kaplonski (slaweq)]

I see couple of potential problems here:

- it seems to be config (backend) driven API as one backend will allow to plug different network types into the same router and other don't,

- what about existing routers which already have connected 2 different types of network? Maybe without Floating IPs used at all so there is no issue for such user at all but now this will be prohibited.

- what about migration from e.g. ML2/OVS to ML2/OVN?