[Kea-users] DHCPv6 DUID-LL matching

[Marcin Siodelski]

Marek,

Have you configured MAC sources correctly? Since you're using MAC 
address as host identifier you should also instruct the server where to 
get the client's MAC address from. This is achieved by listing MAC 
sources as described here:

https://kea.readthedocs.io/en/kea-2.6.1/arm/dhcp6-srv.html#mac-hardware-addresses-in-dhcpv6

Note that one of the sources can be DUID-LL. So you can do this:

"mac-sources": [ "duid" ]

If nothing else you should also just be able to specify DUID-LL directly:

{
"hostname": "host",
"duid": "03:01:01:02:03:04:05:06",
"ip-addresses": [ "fc00::7" ]
}

I am not sure what exactly is changing in this client's DUID, though. 
Isn't DUID-LL stable for this client?

Kind Regards,
Marcin Siodelski
ISC

On 29.11.2024 09:10, Marek Greško via Kea-users wrote:
> Hello,
>
> I have working kea dhcpv6 setup. I am struggling with one problem. All 
> my devices get correct IPv6 addresses from reservations by matching 
> DUID. But one of the devices in the network have changing DUID, only 
> the DUID-LL part is constant, so I tried to match on DUID-LL. I am 
> convinced it was working before, but I cannot verify now. Nowadays I 
> observe the device is getting the IPv6 address from pool. Not from the 
> reservations.
>
> My config contains:
>
>       "host-reservation-identifiers": ["duid", "hw-address"],
>
> and the reservation itself:
>
> {
> "hostname": "host",
> "hw-address": "01:02:03:04:05:06",
> "ip-addresses": [ "fc00::7" ]
> }
>
> The addresses are example one, not the real. What could be the 
> problem? I tried to delete the lease from the leases file and restart 
> the kea, so it is not the lease before reservation problem, but the 
> lease was again offered from the pool.
>
> Thanks
>
> Marek
>
>