[Kea-users] DHCPv4 Conflict resolution on MAC change

[Kevin P. Fleming]

On Fri, Jan 27, 2023, at 14:58, Simon wrote:
> GIRSTMAIR Tobias via Kea-users <kea-users at lists.isc.org> wrote:
>
>> As a workaround, an operator could manually delete the lease with kea-
>> shell (or its underlying api), but that does not scale to our size.
>
> In what way doesn’t size ?
>
> Your problem isn’t new - it’s somewhat fundamental to complying with 
> the RFCs. You will need to remove any existing lease for the IP before 
> the IP can be allocated to another client.
> I assume it doesn’t scale in terms of having multiple hell desk 
> operators having to do manual steps - in which case, the answer is to 
> build a tool into your management toolset allowing them to “click here 
> to remove the lease” when they are altering the reservation details.

If the OP *really* wanted to, they could probably write a Kea plugin which:

* Notices the configuration has been reloaded.

* Compares all of the host reservations in the configuration against the currently-known leases.

* Removes any leases for reserved addresses where the MAC address in the lease is not the MAC address in the reservation.