In T411081: Improve how virt networks are configured in cloudgw I noticed that the v4 variant of the octavia-lb-mgmt-net network is blocked from accessing the internet, but the v6 variant can access it just fine. (Or at least there's nothing I can see preventing access, I didn't actually check.) We should double-check that Octavia really works without internet access (and fix it if it doesn't) and then fix the network to block internet access for both variants.