PPPoE, Point-to-Point Protocol over Ethernet, is a network protocol for encapsulating Point-to-Point Protocol (PPP) frames inside Ethernet frames. It is used mainly with ADSL services where individual users connect to the ADSL transceiver (modem) over Ethernet and in plain Metro Ethernet networks. (more on Wikipedia).

Installing Debian from the start a PPPoE enabled system

Debian Installer, starting with February 2007 supports installing a system via PPPoE and will configure the system accordingly. At the regular Debian Installer boot line just append modules=ppp-udeb (e.g.: type installgui modules=ppp-udeb to start a graphical installation via PPPoE).

More information in the Installation Guide, chapter Installing Debian GNU/Linux using PPP over Ethernet (PPPoE).

How to enable PPPoE for an already installed system

In order to make PPPoE run on a Debian station you should follow the following steps:

PPPoE with kernelspace pppoe driver

pppoeconf try to load pppoe kernel module (modprobe -q pppoe). If there is a file /proc/net/pppoe, configuration will be in "kernel_mode". It's the case for a large majority of users because standard Debian installation have a kernel with pppoe compiled in module.

PPPoE with userspace pppoe driver

Alternatively, user-space agent pppoe can be used.