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

[Darren Ankney]

Hi,

There is no mechanism described in DHCPv6 RFCs, that I am aware of, to
make this happen, however.  There would need to be such an RFC before
Kea would be able to provide such a mechanism.  Kea is not even aware
of the prefix that was delegated to your router.  That is a client
function and Kea is a server.  I think that the devices you describe
that do this are probably slicing up an available prefix delegation to
be further delegated to downstream equipment via some method that is
not part of DHCP.  One can imagine such methods.  Kea has extensive
API commands available that would allow automated configuration of
this nature.

Thank you,
Darren Ankney

On Sun, May 31, 2026 at 5:04 AM Gerson Brands via Kea-users
<kea-users at lists.isc.org> wrote:
>
> Hi all,
>
> Current Kea deployments assume statically configured pd-pools.
>
> However, many residential and SMB deployments receive dynamic IPv6
> prefixes via DHCPv6-PD from upstream ISPs.
>
> Examples include Telekom Germany, Vodafone Germany, AVM Fritz!Box,
> OpenWrt and MikroTik deployments.
>
> A common requirement is to reserve a portion of the received upstream
> prefix and further delegate prefixes to downstream routers.
>
> Example:
>
> Upstream prefix:
> 1234:5678:9abc::/56
>
> Downstream router requests:
> - /62
> - /60
> - /62
>
> The DHCPv6 server should be able to derive PD pools dynamically from
> the currently active upstream delegated prefix instead of requiring
> statically configured pd-pools or external configuration generation.
>
> OpenWrt supports this deployment model today.
> AVM Fritz!Box supports this deployment model today.
> MikroTik supports this deployment model today.
>
> Does Kea already support such a deployment model?
> If not, would the Kea team consider support for upstream-prefix-derived
> PD pools as a future feature?
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