Cannot assign dhcrelay CARP IPV6

[drobnymichal]

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Describe the bug

I am unable to get DHCPv6 relay working if there is only a CARP IPv6 address on the given interface.

If there is an IP address directly on the given interface, it works.

I have no problem with DHCPv4 relay.

To Reproduce

Steps to reproduce the behavior:

1. Create CARP VIP (IPv6)
2. Try to create DHCPv6 Realy on the interface with IPv6 CARP VIP
3. Created DHCPv6 relay failed on start. (dhcrelay_configure_id() found no suitable IP address for opt2(vlan0.69))

Expected behavior

No errors.

Describe alternatives you considered

I looked at the code and found this function: (/usr/local/etc/inc/interfaces.inc line 4094)

 foreach (interfaces_addresses($interface, false, $ifconfig_details) as $addr) {
     /* XXX consider excluding 'autoconf', but only when it's not in SLAAC mode */
     if ($addr['family'] != 'inet6' || $addr['deprecated'] || $addr['detached'] || $addr['tentative'] || $addr['alias']) {
         continue;                                                           

Here is a filter for IP addresses that are not aliases. When I removed the check on the alias, dhcprelay started normally.

Screenshots

No screenshots.

Relevant log files

opnsense 45373 - [meta sequenceId="108"] /usr/local/sbin/pluginctl: dhcrelay_configure_id() found no suitable IP address for opt2(vlan0.69)

Additional context

No context.

Environment

Software version used and hardware type if relevant, e.g.:

Versions OPNsense 25.10_2-amd64 FreeBSD 14.3-RELEASE-p4 OpenSSL 3.0.18 Licensed until 2026-10-20

Official OPNsense box DEC4240EU.

[Monviech]

@fichtner can this condition be altered?

[fichtner]

@drobnymichal In the old days a "VIP" was a special entity to select for listening explicitly, but that was not a great concept so it's no longer there. This now seems to revolve around get_interface_ip(v6) functions not being able to cope with ambiguity.

Let me see if I can fix this.

Cheers, Franco

[fichtner]

I haven't tested this yet so beware, but I think the approach in 1af287d is what you were looking for.