@seb128 I have created a new bug report with links to the upstream commits. The core of the issue is that IPv6 addresses are now being added in the wrong order, so the kernel prefers SLAAC addresses over DHCPv6 addresses, which should be the other way around.
As this is a breaking change in source-based IPv6 routing in an LTS release, I think the impact is severe. In my opinion, this update should never have reached stable, especially because this bug is known upstream and fixed in a later version. I'm already quite stressed how this will turn out at work after the weekend. We use source-based ACL's on all of our firewalls, giving static DHCPv6 leases to our client devices. Now all of a sudden those addresses are no longer being used for outgoing traffic, but instead the non-controllable SLAAC-addresses are. This will lock everyone out of all servers. The only way to get the proper addresses to be preferred again seems to be to disable SLAAC on the router, because any local setting in NetworkManager no longer works. I can disable SLAAC without issues at home, because everything is 100% Ubuntu and Debian there. But in environments with other OS'es that don't support DHCPv6 (like Android), disabling SLAAC will break IPv6 on all such devices. Moreover, not everybody controls their own routers, so this really isn't much of a solution. Other options would be to downgrade and apt-mark hold network-manager on all Ubuntu 22.04 devices, or to completely change server firewall infrastructure by whitelisting prefixes. As you can see, none of these options sound appealing. So regarding the regression potential: it has severely regressed IPv6 handling, and definitely *not* fixed things. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1974428 Title: Update to the current 1.36 stable version To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/1974428/+subscriptions -- ubuntu-bugs mailing list email@example.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs