Has anyone got IPv6 working in Proxmox debian LXCs?

LanguageDensity@lemmy.world to Selfhosted@lemmy.world – 9 points –

I have tried using the debian 10/11/12 LXC templates on Proxmox, but I can't get IPv6 to work as expected. Which is weird, since just setting IPv6 to SLAAC/auto works as expected for ubuntu 20.04 containers with no additional configuration in the container itself.

What I encountered:

  1. Debian overrides the DNS settings set in proxmox with values from DHCP
  2. DHCPv6 DNS updates required manually setting send fqdn.fqdn "..."; in dhclient.conf
  3. DHCPv6 DNS updates only work when manually calling dhclient -6

Those all can be fixed, but are bit of a pain, since I have to manually update configuration files in the container itself. I also have to duplicate the configuration, for example the hostname/domain name in the configuration.

Has anyone got IPv6 working on debian LXCs without any additional config in each container? Or any ideas what's different between the debian and ubuntu LXCs?

5

Not realty helpful but SLAAC was working fine on pure Debian at least back to buster. Sorry, do not have that machine around anymore.

Yeah, SLAAC works as expected on Debian 10-12 LXCs as well, only DHCPv6 has issues.

Last time I checked this was a known bug. DHCPv6 would even cause many containers to not start or to not get an address.

Ok, thanks, guess I'll stick with Ubuntu 20.04 for as long as possible, hopefully IPv6 support improves until then. I'm really surprised by the amount of IPv6 bugs in Debian, some of them even over a decade old, for example simply not being able to configure sssd without IPv4.

I think I misunderstood you. The one I was talking about was a bug in proxmox. If it's an issues inside lxc, you can replicate the Ubuntu networking stack using nmcli or use systemd-networkd and resolved directly. It behaves identically as far as I know.