Here are my notes how to configure pppoe-server to run as server for ADSL modem.

Prerequisits

This list might be incomplete

apt-get install pppoe

PPP configuration

/etc/ppp/pppoe-server-options

# PPPoE server
#nologin
mru 1492
noreplacedefaultroute
proxyarp
ms-dns 192.168.1.1

/etc/ppp/pap-secrets

# PPPoE server
#client	hostname	<password>	IP
test	*			"test"		*

/etc/ppp/chap-secrets

# client	server	secret	IP addresses
test		*		test	*

Configuration

Setup network to start PPPoE server on (we don't really need it, but pppoe-relay requires two interfaces and we need pppoe-relay to respond to PADI requests from ADSL modem)

ifconfig eth0:1 10.0.0.1 up

PADI

pppoe-relay -B eth0:1 -C eth0 -n 1 -F

PPPoE

pppoe-server -I eth0:1 -T 60 -C fake -S fake -L 10.0.0.2 -R 10.0.0.10 -N 1 -F

Debugging

To sniff all traffic expect web (I guess that most ADSL modems have web interface) use something like:

tshark -i eth0 -f '!port 80'