IPv6 delegated prefix is updated on LAN interface but not for LAN devices

[TrustedComputer]

Configuration details below. As in the title, the IPv6 delegated prefix is never getting updated for LAN devices. I'm not using DHCPv6 on the LAN, I only want SLAAC addresses. This works for the most part. But for some reason, when the delegated prefix changes (thanks, Starlink), the prefix is updated on the (tracking) LAN interfaces but RADVD never gets updated.

If on Interfaces/Overview/WAN I click reload for DHCPv4/v6, then it immediately updates and the devices are all happy with correct IPv6 addresses. Is there something wrong in the config below, or is this a known issue? I checked github for issues and some of them seem like they could apply but I am not sure.

OPNsense 22.7.11_1-amd64
ISP: Starlink with CGNAT and IPv6: WAN Address stays the same, but delegated prefix changes every few days
WAN IPv6 Configuration Type: DHCPv6
Request only an IPv6 prefix: Checked
Prefix delegation size: 56
Send IPv6 prefix hint: Not Checked
Use IPv4 connectivity: Not Checked
Use VLAN priority: Not Checked
LAN  IPv6 Configuration Type: Track Interface
Track IPv6 Interface: WAN
IPv6 Prefix ID: 0x0
Manual configuration: Allow manual adjustment of DHCPv6 and Router Advertisements : Checked
Enable DHCPv6 server on LAN interface: Not Checked
Available prefix delegation size: 57 bits (informational only field)
Router Advertisements: Unmanaged
Router Priority: Normal

[franco]

This might help: https://github.com/opnsense/core/commit/3cb2dd7669a

# opnsense-patch 3cb2dd7669a


Cheers,
Franco

[TrustedComputer]

Thanks, Franco!

Unfortunately, I get this:

Code Select Expand

Fetched 3cb2dd7669a via https://github.com/opnsense/core
1 out of 1 hunks failed while patching etc/inc/plugins.inc.d/dhcpd.inc

I assume it's because I'm not updated with 23.1 yet, correct?

[franco]

Sorry I didn't look closely enough. Yes, this is only relevant for 23.1.x.

I'd suggest updating anyway as 22.7 is no longer supported.

And thanks for the detailed report points. Most of the time we get "my ipv6 doesn't work" and it's frustrating for everyone involved. ;)


Cheers,
Franco

[TrustedComputer]

I got the client's firewall upgraded and the patch has been applied. I'll update here the results here when the prefix changes for future people finding this topic by search.

[TrustedComputer]

Well, two and a half weeks later and the IPv6 addresses and prefixes have not changed since installing the patch. So I can't say whether or not this works for us or not. But stable prefixes are even better!

Moral of the story is... I guess you never know what to expect with the "better than nothing beta" Starlink.  :)

[franco]

FWIW, we have been working on properly dealing with shifting prefixes and RENEW/REBIND behaviour for DHCPv6 connectivity. I think the patches might even hit 23.1.8.


Cheers,
Franco