Comment 40 for bug 1895822

Ok so I think it's the bridgemap & network config. Doing the upgrade using the documentation with the following configuration works fine:

  NeutronPublicInterface: eth1
  NeutronBridgeMappings: "datacentre:br-ctlplane"
  NeutronPhysicalBridge: br-ctlplane

In CI, we only configure NeutronPublicInterface: br-ex. NuetronPhysicalBridge is br-ex by default. So it appears that the br-ctlplane interface that we use with br-ex is not being properly connected.

I think what happens is we have:

br-ex -> br-ctlplane (with ips)
 ^- neutron

So routing gets weird. I think we need

br-ex -> br-ctlplane (with ips)
            ^- neutron