Presumably you have an adsl modem with a provider which uses pppoe, and the adsl modem doesn't do pppoe internally? If so, I would either a) get an adsl modem with pppoe support built-in, or b) get a wi-fi router with pppoe support and connect it to the adsl modem.

There's a pppoe client for desktop debian though, but I don't know of a version compiled for N8x0. But pppoe should really be handled at the wall, not by the computers you connect to the network. IMO.