/dev/null

For a PPPoE Passthrough on DD-WRT, enable jffs and do the following steps on a *nix-based system

cd /tmp;
wget http://kamikaze.openwrt.org/8.09.1/brcm-2.4/packages/rp-pppoe-relay_3.10-1_mipsel.ipk;
tar zxf rp-pppoe-relay_3.10-1_mipsel.ipk;
tar zxf data.tar.gz;
scp usr/sbin/pppoe-relay root@:/tmp/

Start the relay agent on the router

/tmp/pppoe-relay -S vlan1 -C br0

Now you can start your pppoe client on your notebook.

Tested with a WRT54G and DD-WRT v23 !