When will IPv6 prefix-delegation on opnsense work again?

[Bytechanger]

Hi,

I run the OPNSense behind a FritzBox.
The FritzBox delegates ipv6 to OPNSense.
This worked wonderfully up until version 24.7.5_3.

Since then (24.7.11_2) the FritzBox stopped delegating ipv6-networks to the OPNSense!
However, the WAN connection receives an ipv6 address from the FB network.

So after Verson 24.7.5_3 ipv6-Delegation is broken!
So I stuck on Version 24.7.5_3!!

Greets

[troplin]

I'm also running OPNsense behind a FritzBox and I don't see any problems with PD.
Maybe there's something specific with your config that causes problems?

[Bytechanger]

What could the problem?
Running under 24.7.5_3 but above not?
When I restore Backup from this version in Proxmox it runs well immediately.

Same config, starting update, then it doesnt work anymore!
Restore Backup from 30 minutes ago, old version, runs well and gets ipv6 pd fast.

@troplin:
Did you get an ipv6 prefix? Wich size?
Mine is 60
(because FritzBox get its own networks for guest automatic).

[Bytechanger]

Hey,

Does it work for the rest of you?
I have my OPNSense behind the Fritzbox.
It is connected as an exposed host.
 
In the FritzBox I have -Assign DNS server, prefix (IA_PD) and IPv6 address (IA_NA)- and -Also allow IPv6 prefixes that other IPv6 routers in the home network b- activated.
My ISP send the FritzBox /56 networks for delegation.
In OPNSense I set delegation size to /60.

This works in the old OPNSense version.
At the new versions, I don't get any networks for delegation from the Fritzbox.

I tried different things:
-Request Prefix Hint only ON/OFF, etc.
Are there any logs I could include here?

Need help please

Greets

[dseven]

Are there any logs I could include here?

dhcp6c goes to the system log (System -> Log files -> General). You might want to set Interfaces -> Settings -> IPv6 DHCP -> Log level to at least Info, if not Debug.
 

[Bytechanger]

Hi,

so I set IPv6 DHCP loglevel to Debug.

On working version of opnsense 24.7.5_3 its

Code Select Expand

2025-01-16T06:34:06 Notice kernel <3>RA with a lower CurHopLimit sent from fe80:5::XXXX:XXXX:fef7:d970 on vtnet4 (current = 255, received = 64). Ignored.
2025-01-16T06:34:01 Notice dhcp6c XID mismatch
2025-01-16T06:34:01 Notice dhcp6c IA_PD prefix: 2a00:XXXX:XXXX:65f0::/60 pltime=3600 vltime=7200
2025-01-16T06:34:01 Notice dhcp6c get DHCP option IA_PD prefix, len 25
2025-01-16T06:34:01 Notice dhcp6c IA_PD: ID=4, T1=1800, T2=2880
2025-01-16T06:34:01 Notice dhcp6c get DHCP option IA_PD, len 41
2025-01-16T06:34:01 Notice dhcp6c IA_NA address: 2a00:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX:d970 pltime=3600 vltime=7200
2025-01-16T06:34:01 Notice dhcp6c get DHCP option IA address, len 24
2025-01-16T06:34:01 Notice dhcp6c IA_NA: ID=4, T1=1800, T2=2880
2025-01-16T06:34:01 Notice dhcp6c get DHCP option identity association, len 40
2025-01-16T06:34:01 Notice dhcp6c unknown or unexpected DHCP6 option opt_86, len 16
2025-01-16T06:34:01 Notice dhcp6c get DHCP option opt_86, len 16
2025-01-16T06:34:01 Notice dhcp6c get DHCP option DNS, len 16
2025-01-16T06:34:01 Notice dhcp6c preference: 0
2025-01-16T06:34:01 Notice dhcp6c get DHCP option preference, len 1
2025-01-16T06:34:01 Notice dhcp6c DUID: 00:XX:00:XX:XX:XX:XX:XX:XX:14
2025-01-16T06:34:01 Notice dhcp6c get DHCP option server ID, len 10
2025-01-16T06:34:01 Notice dhcp6c DUID: 00:XX:XX:01:XX:XX:XX:XX:00:XX:2e:XX:XX:83
2025-01-16T06:34:01 Notice dhcp6c get DHCP option client ID, len 14
2025-01-16T06:34:01 Notice dhcp6c receive advertise from fe80::XXXX:XXXX:fea4:e514%vtnet4 on vtnet4
2025-01-16T06:34:01 Notice dhcp6c reset a timer on vtnet4, state=SOLICIT, timeo=5, retrans=35289
2025-01-16T06:34:01 Notice dhcp6c send solicit to ff02::1:2%vtnet4
2025-01-16T06:34:01 Notice dhcp6c set IA_PD
2025-01-16T06:34:01 Notice dhcp6c set IA_PD prefix
2025-01-16T06:34:01 Notice dhcp6c set option request (len 4)
2025-01-16T06:34:01 Notice dhcp6c set elapsed time (len 2)
2025-01-16T06:34:01 Notice dhcp6c set identity association
2025-01-16T06:34:01 Notice dhcp6c set client ID (len 14)
2025-01-16T06:34:01 Notice dhcp6c Sending Solicit
2025-01-16T06:33:50 Notice kernel <3>RA with a lower CurHopLimit sent from fe80:5::XXXX:XXXX:fef7:d970 on vtnet4 (current = 255, received = 64). Ignored.
2025-01-16T06:33:43 Notice dhcp6c XID mismatch
2025-01-16T06:33:43 Notice dhcp6c IA_PD prefix: 2a00:6020:4021:65f0::/60 pltime=3600 vltime=7200
2025-01-16T06:33:43 Notice dhcp6c get DHCP option IA_PD prefix, len 25
2025-01-16T06:33:43 Notice dhcp6c IA_PD: ID=4, T1=1800, T2=2880
2025-01-16T06:33:43 Notice dhcp6c get DHCP option IA_PD, len 41
2025-01-16T06:33:43 Notice dhcp6c IA_NA address: 2a00:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX:d970 pltime=3600 vltime=7200
2025-01-16T06:33:43 Notice dhcp6c get DHCP option IA address, len 24
2025-01-16T06:33:43 Notice dhcp6c IA_NA: ID=4, T1=1800, T2=2880
2025-01-16T06:33:43 Notice dhcp6c get DHCP option identity association, len 40
2025-01-16T06:33:43 Notice dhcp6c unknown or unexpected DHCP6 option opt_86, len 16
2025-01-16T06:33:43 Notice dhcp6c get DHCP option opt_86, len 16
2025-01-16T06:33:43 Notice dhcp6c get DHCP option DNS, len 16
2025-01-16T06:33:43 Notice dhcp6c preference: 0
2025-01-16T06:33:43 Notice dhcp6c get DHCP option preference, len 1
2025-01-16T06:33:43 Notice dhcp6c DUID: 00:XX:XX:XX:XX:XX:XX:XX:XX:14
2025-01-16T06:33:43 Notice dhcp6c get DHCP option server ID, len 10
2025-01-16T06:33:43 Notice dhcp6c DUID: 00:01:00:XX:XX:XX:XX:fc:XX:01:XX:XX:XX:XX
2025-01-16T06:33:43 Notice dhcp6c get DHCP option client ID, len 14
2025-01-16T06:33:43 Notice dhcp6c receive advertise from fe80::XXXX:XXXX:fea4:e514%vtnet4 on vtnet4
2025-01-16T06:33:43 Notice dhcp6c reset a timer on vtnet4, state=SOLICIT, timeo=4, retrans=17867
2025-01-16T06:33:43 Notice dhcp6c send solicit to ff02::1:2%vtnet4
2025-01-16T06:33:43 Notice dhcp6c set IA_PD
2025-01-16T06:33:43 Notice dhcp6c set IA_PD prefix
2025-01-16T06:33:43 Notice dhcp6c set option request (len 4)
2025-01-16T06:33:43 Notice dhcp6c set elapsed time (len 2)
2025-01-16T06:33:43 Notice dhcp6c set identity association
2025-01-16T06:33:43 Notice dhcp6c set client ID (len 14)
2025-01-16T06:33:43 Notice dhcp6c Sending Solicit
When I update (OPNsense 24.7.12_2-amd64) there is NO entry in log for dhcp6c, I wait over an hour!
WAN get´s its ipv6 but no prefix and delegate!
I restart OPNSense and also push Reload on Interface-Overview-WAN Interface. No change.

Greets

[Bytechanger]

When I check
sudo ps uxawww | grep dhcp6c
Andreas       31169   0.0  0.0    12720    2296  0  S+   10:41     0:00.00 grep dhcp6c

there is no dhcp6c process running?!
How can I start it??

Greets

[Ben S]

In the absence of any better ideas, you could try:

Code Select Expand

sh -x /var/etc/rtsold_script.sh  em0
(replace em0 with WAN interface)

If I kill dhcp6c and run that the expected output is something like

Code Select Expand

+ [ -z em0 ]
+ grep -q '^interface em0 ' /var/etc/radvd.conf
+ [ -n '' ]
+ [ -f /var/run/dhcp6c.pid ]
+ [ -f /var/run/dhcp6c.pid ]
+ /usr/bin/logger -t dhcp6c 'RTSOLD script - Starting dhcp6c daemon'
+ /usr/local/sbin/dhcp6c -c /var/etc/dhcp6c.conf -p /var/run/dhcp6c.pid -D
If that works, and you see dhcp6c running, the question is why isn't it starting automatically.  If that doesn't work then you might have to look through logs to see if there are any errors logged.  Perhaps somehow there is something invalid in the dhcp6c config file for example.

[Bytechanger]

Hi,

I will test it.
But I think, dhcp6c doesn´t start, because it didn´t get an prefix?

Code Select Expand

2025-01-26T12:58:20 Warning opnsense /usr/local/sbin/pluginctl: dhcpd_dhcp6_configure() found no suitable IPv6 address on opt1(vtnet3)
2025-01-26T12:58:20 Warning opnsense /usr/local/sbin/pluginctl: dhcpd_dhcp6_configure() found no suitable IPv6 address on opt2(vtnet2)
2025-01-26T12:58:20 Warning opnsense /usr/local/sbin/pluginctl: dhcpd_dhcp6_configure() found no suitable IPv6 address on lan(vtnet1)
On WAN it gets an ipv6 adress from fritzbox, but it didn´t get an prefix delegated?!

[Bytechanger]

So,

after I do a fresh installation, it works fine (after restore my config).
But when I recover all plugins, it stops working after a reboot. So I think, a plugin will break prefix delegation?

Greets