[RP-PPPoE] Assigning IP based on MAC address

[Thomas Hewton-Waters]

Is it possible for the server to "remember" what IP it previously
handed out to a client, so when a client disconnects and then
reconnects, it gives it the same IP address? I'm looking to be able to
do this based on the MAC address of the client and not the
username/password that is entered to connect to the server.

If this isn't currently possible, any input on how difficult it would
be to add to the current server?

Any help is much appreciated!

Thanks,
Thomas