Proxy Server IPtables

Creating a Proxy server to pass services from one IP to another using IPTables

A simple script will do :

#!/bin/bash

iptables -F INPUT
iptables -F OUTPUT
iptables -F FORWARD

iptables -t nat -F PREROUTING -t nat
iptables -t nat -F POSTROUTING -t nat

iptables -A PREROUTING -t nat -d 103.3.173.82 -p udp --dport 53 -j DNAT --to 103.3.173.221
iptables -A PREROUTING -t nat -d 103.3.173.82 -p tcp -m multiport --dport 3306,80,443,110,2525,25,20,21,143,2222 -j DNAT --to 103.3.173.221

iptables -A POSTROUTING -t nat -d 103.3.173.221 -j SNAT --to 103.3.173.82