Kea DHCPv6 doesn't register a static allocation in DNS for one single entry, others work just fine

IonutIT

So this is weird. I use Kea for both DHCP and DHCPv6 and most clients on the network have static allocations. DNS registration of those clients work just fine, with the exception of one single entry an IPv6 static allocation.

I've tried removing the entry, setting it again, changing it's IP, nothing seems to work. DNS registration for IPv4 works just fine for this host, but not for IPv6. All other entries, for all other hosts both in IPv4 and IPv6 work just fine.

Gertjan

@IonutIT

Ask pfSense what's going on ?

Read this : How to change Kea DHCP log level and you get my point : what can be done for IPv4 : lease logging, can be done for IPv6 also :

Paste this under Services > DHCPv6 Server > Settings - the bottom : Custom Configuration > JSON Configuration :

{
  "loggers": [
    {
      "name": "kea-dhcp6.leases",
      "output-options": [
        {
          "output": "/var/log/kea-dhcpv6.log",
          "maxver": 8,
          "maxsize": 204800,
          "flush": true,
          "pattern": "%d{%j %H:%M:%S.%q} %c %m\n"
        }
      ],
      "severity": "INFO"
    }
  ]
}

and save.

From on you have an dedicated IPv6 lease log file (not shown in the GUI).

Open a console or SSH, menu option 8 and :

tail -f /var/log/kea-dhcpv6.log

Now, run to the device in question and type

ipconfig /renew6

if it's a Windows device, and come back to pfSense and admire the results.

I tested this, and saw :

[25.07.1-RELEASE][root@pfSense.bhf.tld]/root: tail -f /var/log/kea-dhcpv6.log
235 13:04:03.247 kea-dhcp6.leases DHCP6_LEASE_RENEW duid=[00:01:00:01:26:59:df:8d:a4:bb:6d:ba:16:a1], [no hwaddr info], tid=0x5ba155: lease for address 2a01:xxxx:907:a6e2::c7 and iaid=161790829 has been allocated
235 13:04:03.258 kea-dhcp6.leases DHCP6_LEASE_RENEW duid=[00:01:00:01:26:59:df:8d:a4:bb:6d:ba:16:a1], [no hwaddr info], tid=0x5ba155: lease for address 2a01:xxxx:907:a6e2::c7 and iaid=161790829 has been allocated

My 00:01:00:01:26:59:df:8d:a4:bb:6d:ba:16:a1 was exactly the one I used for the static DHCPv6 setup.
What was the issue ? Did the DUID match ?

IonutIT

@Gertjan

I think you misunderstood, the lease works fine, the machine gets the proper IP, it just that it doesn't register the IPv6 to the DNS Resolver.