#!/bin/sh # Load the NAT module (this pulls in all the others). modprobe iptable_nat # Turn on IP forwarding echo 1 > /proc/sys/net/ipv4/ip_forward # In the NAT table (-t nat), Append a rule (-A) after routing (POSTROUTING) # which says to MASQUERADE the connection (-j MASQUERADE). iptables -t nat -A POSTROUTING -s 192.168.50.0/24 -j MASQUERADE # Allows forwarding specifically to our LAN iptables -A FORWARD -s 192.168.50.0/24 -j ACCEPT # Allow dhcp requests iptables -A INPUT -i eth1 -p udp --sport bootpc --dport bootps -j ACCEPT iptables -A INPUT -i eth1 -p tcp --sport bootpc --dport bootps -j ACCEPT iptables -A INPUT -i eth1 -p udp --sport bootps --dport bootpc -j ACCEPT iptables -A INPUT -i eth1 -p tcp --sport bootps --dport bootpc -j ACCEPT # Allow dns requests iptables -A INPUT -i eth1 -p udp --dport domain -j ACCEPT iptables -A INPUT -i eth1 -p tcp --dport domain -j ACCEPT # Trans parent proxy iptables -t nat -A PREROUTING -i eth1 -p tcp --dport 80 -j REDIRECT --to-port 3128