#!/bin/sh
# Change the part after the = to the where you
# IPTABLES is on your system

IPTABLES=/sbin/iptables

# Flush existing rules

$IPTABLES -F INPUT

# Allow connections going outbound
# from this machine to reply back

$IPTABLES -A INPUT -j ACCEPT -m state --state \
   ESTABLISHED -i eth0 -p icmp

$IPTABLES -A INPUT -j ACCEPT -m state --state \
   ESTABLISHED -i eth0 -p tcp

$IPTABLES -A INPUT -j ACCEPT -m state --state \
   ESTABLISHED -i eth0 -p udp

#Allow incoming SSH requests

$IPTABLES -A INPUT -p tcp --dport 22 -j ACCEPT

#Allow incoming DNS

$IPTABLES -A INPUT -p udp --dport 53 -j ACCEPT
$IPTABLES -A INPUT -p tcp --dport 53 -j ACCEPT

#Allow incoming HTTP requests (to Web server)

$IPTABLES -A INPUT -p tcp --dport 80 -j ACCEPT
$IPTABLES -A INPUT -p tcp --dport 443 -j ACCEPT



#Allow Ping echo

$IPTABLES -A INPUT -p icmp -j ACCEPT

# Load Modules
        insmod ip_conntrack_ftp
        insmod ipt_LOG
        insmod ipt_REJECT
        insmod ipt_limit
        insmod ipt_state

# The logging is set so if more than 5 packets are dropped
# in three seconds they will be ignored. This
# helps to prevent a DOS attack
# Crashing the computer the firewall is running on

$IPTABLES -A INPUT -m limit --limit 3/second \
--limit-burst 5 -i ! lo -j LOG

# Drop and log all other data

$IPTABLES -A INPUT -i ! lo -j DROP