Comment 12 for bug 1866139

to be clear when useing libvirt/qemu GARP should not be sent on provider network after live migration. qemu shoudl send RARP packets. if you are using qemu 2.6.0 this is broken as i mentioned on the mailing list http://lists.openstack.org/pipermail/openstack-discuss/2020-April/014530.html

neutron is not responsible for sending the RARP packets that is done by qemu but there is a known race when usign the ovs firewall driver. it is tracked by two bugs
specifcly these https://bugs.launchpad.net/neutron/+bug/1815989 and https://bugs.launchpad.net/neutron/+bug/1734320

this bug is just a dubplicate of https://bugs.launchpad.net/neutron/+bug/1815989

to fix this we need to update https://review.opendev.org/#/c/640258 so it works again so that the ovs agent can correctly wire up the ovs port before the qemu tap device is created.
and then in nova we need to update https://review.opendev.org/#/c/602432/

i stoped working on this a few months ago becasue when i had a workign version i could not get it merged and when i finally started to get review i nolonger had time left to work on it.

that siad its coming up a lot now as people seam to finally be deploying rocky+

if people have time to take those over it would be great if someone form the neutron team could complete the neutron agent patch.

if not i might try to make time to look at this again but i will need to go set up an env and try and fiture out how to make the neutron patch work again which will take time.