#!/bin/sh

# Delete all existing rules
/sbin/iptables -F
/sbin/iptables -X

# Set default chain policies
/sbin/iptables -P INPUT DROP
/sbin/iptables -P FORWARD DROP
/sbin/iptables -P OUTPUT ACCEPT

# Allow unlimited traffic on loopback
/sbin/iptables -A INPUT -i lo -j ACCEPT
/sbin/iptables -A OUTPUT -o lo -j ACCEPT

# Allow incoming SSH
/sbin/iptables -A INPUT -i eth0 -p tcp --dport 22 -m state --state NEW,ESTABLISHED -j ACCEPT
/sbin/iptables -A OUTPUT -o eth0 -p tcp --sport 22 -m state --state ESTABLISHED -j ACCEPT

# Allow established connections
/sbin/iptables -A INPUT -i eth0 -m state --state ESTABLISHED,RELATED -j ACCEPT