[neutron] East-West networking issue on DVR after failed attempt at starting a new instance

J-P Methot jp.methot at planethoster.info
Thu Oct 7 21:37:37 UTC 2021


We use Openstack Wallaby installed through Kolla-ansible on this setup. 
Here's a quick rundown of the issue we just noticed:

-We try popping an instance which fails because of a storage issue.

-Nova tries to create the instance on 3 different nodes before failing.

-We notice that instances on these 3 nodes and only those instances 
cannot connect to each other anymore.

-Doing Tcpdump tests, we realize that pings are received by each 
instance, but never replied to.

-Restarting the neutron-openvswitch-agent container fixes this issue.

I suspect l2population might have something to do with this. Is the ARP 
table rebuilt when the openvswitch-agent is restarted?

Jean-Philippe Méthot
Senior Openstack system administrator
Administrateur système Openstack sénior
PlanetHoster inc.

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