Here are my notes how to configure pppoe-server to run as server for ADSL modem.
This list might be incomplete
apt-get install pppoe
# PPPoE server #nologin mru 1492 noreplacedefaultroute proxyarp ms-dns 192.168.1.1
# PPPoE server #client hostname <password> IP test * "test" *
# client server secret IP addresses test * test *
We will have fake network 10.0.0.0 on IP alias eth0:1 and will give out addresses in that range. While we could go with just one network, this is more clean, since we will see difference in packets traveling over PPP link as opposed to direct connection.
ifconfig eth0 192.168.1.90 up ifconfig eth0:1 10.0.0.1 up
pppoe-relay -B eth0:1 -C eth0 -n 1 -F
pppoe-server -I eth0:1 -T 60 -C fake -S fake -L 10.0.0.2 -R 10.0.0.10 -N 1 -F
iptables -t nat -A POSTROUTING -s 10.0.0.0/24 -j SNAT --to-source 192.168.1.90
To sniff all traffic expect web (I guess that most ADSL modems have web interface) use something like:
tshark -i eth0 -f '!port 80'