ISC DHCPv6: Router chain: IPv6 Prefix delegation not working anymore

[stefan00]

Hi folks,

I cannot get dynamic v6 prefixes delegated to a OPNsense downstream router ("Slave" see below) anymore. PD from FritzBox to the first OPNsense box in the chain works fine. Pretty stuck here.

Router chain Setup:

A) Fritzbox (/56 assigned)
  -> B) OpnSense Master (/57 assigned)
    -> C) OpnSense Slave (/59 expected, not assigned)

The exact same setup has worked fine previously, with the drawback of needing to reboot the Slave C) sometimes after it lost the prefix. However since updating to the latest OPNSense releases on both boxes yesterday, prefix delegation has stopped completely. Played with felt every possible setting already but can not get v6 networks delegated to the C) Slave.

Please see the screenshots of the settings below.

Did anything dramatically change?

Screenshot: B) OpnSense Master DHCP Server config

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[stefan00]

Sorry for the next post, but screenshots took too much attachment space (300kb limit).

So the text image: B) Master delegated prefix table (empty)

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[stefan00]

third screenshot: C) OpnSense client router DHCP interface settings

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[dseven]

Your prefix delegation range looks wrong. It needs to be the start of a /59 prefix - "::a0" is (obviously?) not that...

[Monviech (Cedrik)]

Also consider using KEA for the dynamic prefix delegation to stay in the supported scope:

https://docs.opnsense.org/manual/kea.html#prefix-delegation-ia-pd

Additional to the above documentation I also answered some question about it here recently:
https://forum.opnsense.org/index.php?topic=52169.0