[Kea-users] KeaDHCPv6 to derive downstream PD pools from ISP PD

[Simon]

On 8 Jun 2026, at 16:29, Sten Carlsen via Kea-users <kea-users at lists.isc.org> wrote:

> How about looking at the issue this like:
> 
> 	• Dhcp client running on the gateway and also dhcp server on the same machine.
> 	• "Some" SW to look for changes in the client and pushing those to the server.
> 
> This might be simpler as only the connector needs to be new. It could also be written in such a way that client and server could be on separate machines.

It would be the sensible way to handle it. In principle, it would (with the right code & algorithms) handle any method of receiving your prefix delegation - while embedding it in the DHCP server could hardcode support for only certain combinations. At it’s crudest, it could be a shell script tailing the client log.

There is also the secondary issue of deconfiguring a prefix that stops being available - e.g. if the upstream link goes down. It’s also probably worth trawling the IETF IPv6 email histories as there’s been considerable discussion around prefix reconfiguration in flash renumbering events. TBH I didn’t pay that much attention (I get a static allocation from my ISP), but from memory you really need to update your RAs to a short lifetime (zero ?) to tell clients to stop using any old prefix(s) as well as advertising the new one(s).

Simon