Network problem - suddenly no traffic between container(s) and host (as result no DHCP)

Next time it happens also check the journalctl output to see if anything has happened that may be linked to it (interfaces appearing or disappearing for instance).

Managed to reproduce that. This is happening ALWAYS and ONLY after snap updates the lxd package.

Now investigating to identify it there is any log trace or way to fix that.

Does systemctl reload snap.lxd.daemon trigger it?
That’s pretty much all that happens during a refresh.

Hi, thank you very much, I just had this issue today, wasted a couple of hours but finally got it working thanks to you.

@stgraber : systemctl reload ... did not help, but out of desperation I tried systemctl restart ... and it did work! Thank you too for all your work on lxd, I use it every day for all kinds of things.

snap deserves to die in a fire, has caused me many wasted hours since I met it by surprise years ago. I would remove it and reinstall lxd without it if that’s possible, but I’m afraid of it destroying my containers in this machine so I’ll just try to remember next time I set up a host.

This is most likely a conflict between the ordering of existing firewall rules on the system and the ones that LXD set up on restart. This commonly happens if Docker is installed on the same host.

See How to configure your firewall - LXD documentation