#!/bin/bash
iptables -A INPUT -i lo -j ACCEPT

iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -m state --state NEW -i ! eth1 -j ACCEPT
iptables -A FORWARD -i eth1 -o eth0 -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A FORWARD -i eth0 -o eth1 -j ACCEPT

iptables -t nat -A POSTROUTING -o eth1 -j MASQUERADE

iptables -A FORWARD -i eth1 -o eth1 -j REJECT

ech0 1 > /proc/sys/net/ipv4/ip_forward