Hi Looking again at the DUID reported by Ubuntu: | 00:02:00:00:ab:11:11:16:f0:97:0e:c5:c9:b6
00:02: the type is enterprise number 00:00:ab:11, aka 43793: systemd 11:16:f0:97:0e:c5:c9:b6: this is by default a hash of the machine id, so does change as well, or is this using the UUID set by the firmware? Does /etc/machine-id have different contents if you rebuild the system using different but similar enough Ubuntu images? On Sat, Jul 31, 2021 at 06:03:33PM +0200, Thomas Goirand wrote: > > So dnsmasq is wrongly configured to take the DUID into account, even if > > it does not matter for the address selection, because the address is > > fixed? > Do you have any suggestion on how to start dnsmasq, so it doesn't take > DUID into account? Is there any parameter to do that? I have no idea. You should talk to Neutron(?) upstream for that. It is quiet possible that dnsmasq does not support this usecase at all. I wasn't able to find anything with reading sources within some minutes. > FYI, I've just opened a thread in the openstack-discuss list to see if > this can be fixed. Though ideally, it'd be nice to have both my > deployment AND the image fixed for this problem, so nobody can ever > encounter the issue again. At least it needs to be added to the documentation prominently, because regardless of what we do, a server rebuild will randomly drop systems out of the ipv6 net. Bastian -- Spock: The odds of surviving another attack are 13562190123 to 1, Captain.