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/// FIREWALL SCRIPT START

#!/bin/bash

# This script allows PORTS on DEVICE
# and blocks everything else on DEVICE

PORTS="80 443 143 22 25 21 20"
DEVICE="eth1"
IPTABLES=`which iptables`

# flush and clean up
$IPTABLES -P INPUT ACCEPT
$IPTABLES -P OUTPUT ACCEPT
$IPTABLES -P FORWARD ACCEPT
$IPTABLES -t nat -P PREROUTING ACCEPT
$IPTABLES -t nat -P POSTROUTING ACCEPT
$IPTABLES -t nat -P OUTPUT ACCEPT
$IPTABLES -t mangle -P PREROUTING ACCEPT
$IPTABLES -t mangle -P OUTPUT ACCEPT
$IPTABLES -F
$IPTABLES -F -t nat
$IPTABLES -F -t mangle
$IPTABLES -X -t nat
$IPTABLES -X -t mangle
$IPTABLES -X


for i in $PORTS; do
 $IPTABLES -A INPUT -i $DEVICE -p tcp --dport $i -j ACCEPT;
 $IPTABLES -A INPUT -i $DEVICE -p udp --dport $i -j ACCEPT;
done;

$IPTABLES -A INPUT -D $DEVICE -m state --state ESTABLISHED,RELATED -j ACCEPT
$IPTABLES -A INPUT -i $DEVICE -m state --state NEW,INVALID -j DROP