#!/bin/sh

#If your distro doesn't load it automatically uncomment the next line.
#modprobe ppp_generic

# Start point to point over ethernet to the ADSL modem
/usr/sbin/pptp 10.0.0.138 file /etc/ppp/options.adsl 2>&1 >/var/log/adsl-pptp.log &

# Grace connect time before proceeding
sleep 5

#We have 2 interfaces to the outside world.
# 10.0.0.150 is the ethernet to the adsl modem (eth2)
# 1.0.0.123 is the pppoe to the adsl modem (ppp0)
# 2.0.0.123 is the expensive but reliable line (eth0)
# 10.0.1.123 is the internal lan (eth1)
# The default route is pointing to the expensive but reliable line

# output of ip route list
# 1.0.0.1 dev ppp0  proto kernel  scope link  src 1.0.0.123
# 2.0.0.1 dev eth0  proto kernel  scope link  src 2.0.0.123
# 10.0.0.0/24 dev eth2  proto kernel  scope link  src 10.0.0.150
# 10.0.1.0/24 dev eth1  proto kernel  scope link  src 10.0.1.123 
# 127.0.0.0/8 dev lo  scope link
# default via 2.0.0.123 dev eth0

# Add a new identifier to the routing table if it does not exist yet.
# echo "200 adsl"  >> /etc/iproute2/rt_tables
# echo "201 lan"  >> /etc/iproute2/rt_tables

# Shuffle the ip routing to do the rule based routing
# anything you bind to this interface will go out over this interface
ip rule add from 1.0.0.123 table adsl
ip route add default via 1.0.0.123 dev ppp0 table adsl

# The internal lan machine 10.0.1.111 will now be routed out over the fast adsl line
# the rest will still be routed over the reliable but expensive line
ip rule add from 10.0.1.111 table lan
ip route add default via 1.0.0.123 dev ppp0 table lan

# Flush the cache make sure the routing switches
ip route flush cache

# The output of ip rule list after these commands
# 0:      from all lookup local
# 32764:  from 10.0.1.111 lookup lan
# 32765:  from 1.0.0.123 lookup adsl
# 32766:  from all lookup main
# 32767:  from all lookup 253