#!/bin/bash
IF_EXTERNA="eth0";
IF_INTERNA="eth1";
REDE_INTERNA="192.168.254.0/24"
iptables -F
iptables -Z
iptables -X
iptables -F -t nat
iptables -X -t nat
iptables -F -t mangle
iptables -X -t mangle
iptables -P FORWARD ACCEPT
iptables -P INPUT DROP
iptables -P OUTPUT ACCEPT
iptables -A INPUT -i lo -j ACCEPT
iptables -A INPUT -i $IF_INTERNA -j ACCEPT
iptables -A FORWARD -i $IF_INTERNA -j ACCEPT
iptables -t nat -A PREROUTING -i $IF_INTERNA -p tcp --dport 80 -j REDIRECT --to-port 3128
iptables -t nat -A POSTROUTING -s $REDE_INTERNA -j MASQUERADE