Comment 3 for bug 1671504

After a call with ajo today I think the premise behind this bug is wrong. We apparently don't even need the l3 agents for the tenant vm IPs. Sure, if all l3 agents are down you won't be able to _create_ new IPs for example but the existing ones should be reachable OK.

If they aren't then there is a bug - like the one discovered testing https://review.openstack.org/#/c/445494/9 that neutron-openvswitch-agent is being started when openvswitch is being updated during the upgrade package update. Another is an issue with 'ryu' and is likely the one I hit on Friday see review comments@ /#/c/445494/). Apparently there are newer package builds from Friday afternoon for neutron-* that might solve some of these.

So, plan today is to test without this change and see where the ping fails using those latest packages, so we can be clearer about any outstanding bugs.