Containers suddenly stopped working since move to core20 snap - No more IP's assigned

[tomp (Thomas Parrott)]

Ah docker. See

Lxd bridge doesn't work with IPv4 and UFW with nftables

As you can see getting the various firewall implementations to play nicely together is a non-trivial task. In the meantime these commands seems to suffice to allow traffic from lxdbr0 interface to the LXD host and for traffic from lxdbr0 to be routed to the external network without allowing all external inbound traffic: sudo ufw allow in on lxdbr0 sudo ufw route allow in on lxdbr0 sudo ufw route allow out on lxdbr0 See our page in the docs about this also:

and

LXD and Docker Firewall Redux - How to deal with FORWARD policy set to drop

It looks like something (docker perhaps) has refreshed the firewall rules and removed the ones LXD added. Assuming your LXD bridge is lxdbr0 then you’re missing these lines: -A FORWARD -o lxdbr0 -m comment --comment "generated for LXD network lxdbr0" -j ACCEPT -A FORWARD -i lxdbr0 -m comment --comment "generated for LXD network lxdbr0" -j ACCEPT before the line: -A FORWARD -j DOCKER-USER