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

Slawek Kaplonski skaplons at redhat.com
Fri Oct 8 06:06:11 UTC 2021


On czwartek, 7 października 2021 23:37:37 CEST J-P Methot wrote:
> Hi,
> 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?

If You are using dvr and l2population, You have arp_reponder enabled so arp 
replies for tunnel networks are done locally in the ovs bridges. When You 
restart neutron-openvswitch-agent, it will regenerate all OF rules so yes, if 
some rules were missing, restart should add them again. 

Slawek Kaplonski
Principal Software Engineer
Red Hat
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 488 bytes
Desc: This is a digitally signed message part.
URL: <http://lists.openstack.org/pipermail/openstack-discuss/attachments/20211008/34fecf37/attachment.sig>

More information about the openstack-discuss mailing list