#!/bin/sh # My system IP/set ip address of server SERVER_IP="65.55.12.13" # Flushing all rules iptables -F iptables -X # Setting default filter policy iptables -P INPUT DROP iptables -P OUTPUT DROP iptables -P FORWARD DROP # Allow unlimited traffic on loopback iptables -A INPUT -i lo -j ACCEPT iptables -A OUTPUT -o lo -j ACCEPT # Allow incoming ssh only iptables -A INPUT -p tcp -s 0/0 -d $SERVER_IP --sport 513:65535 --dport 80 -m state --state NEW,ESTABLISHED -j ACCEPT iptables -A OUTPUT -p tcp -s $SERVER_IP -d 0/0 --sport 80 --dport 513:65535 -m state --state ESTABLISHED -j ACCEPT # make sure nothing comes or goes out of this box iptables -A INPUT -j DROP iptables -A OUTPUT -j DROP