ipv6 trouble here as well, dhcpd6 dies

[Irishfluter]

OPNSense 23.1, ipv6 works but if the cable modem reboots, dhcpd6 dies.  You can restart it but ipv6 connectivity never returns. If you try to release / reload on the WAN interface, dhcpd6 immediately dies again.

To restore ipv6 connectivity, you have to reboot the firewall.

In the previous OPNSense version, same configuration, dhcp6 would stay up past a modem reboot and release / reload worked without killing the service.

[sbellon]

I had exactly the same symptom with VDSL2 and Deutsche Telekom with the 23.1 release as opposed to the 22.7 one.

What helped in my setup, was ticking "Interfaces -> Settings -> IPv6 DHCP: Prevent Release". Since I did that, IPv6 is stable, even across forced disconnects. Not sure whether this helps in your case, I just wanted to mention what helped in mine.

[Irishfluter]

I appreciate the tip!  Unfortunately, did not make any difference in my case.  Exact same symptoms.

[Irishfluter]

I have found a work-around, though I don't quite follow why it works.

After a cable modem reboot / restart, and I log into the firewall, dhcpd6 will be dead.  If I restart dhcpd6 and try to release / reload on the WAN interface, dhcpd6 just dies again.

However, if I start hdcpd6 and then restart the unbound DNS service, I can do a release / reload without dhcpd6 dying, restoring ipv6 connectivity.

[agh1701]

Yes, same problem if the modem reboots either by itself or if I manually reboot it DHCPD6 goes down and must be started.  RADVD must also be restarted and then connectivity is restored.

The mods might be missing this and other posts as they might think its related to the PPPOE DHCPD6 problem that I believe they have fixed.