1 iptables -t mangle -A PREROUTING -s 1.2.3.4 -j ROUTE --oif eth1
2 iptables -t mangle -A PREROUTING -s 1.2.3.5 -j ROUTE --iif eth0 --oif eth2
3 iptables -t mangle -A PREROUTING -s 1.2.3.6 -j ROUTE --oif eth2 --continue
4 iptables -t mangle -A PREROUTING -j ACCEPT
