#!/bin/bash
iptables -F
iptables -P INPUT DROP
iptables -A INPUT -m state --state ESTABLISHED -j ACCEPT
iptables -A INPUT -i lo -j ACCEPT
iptables -A INPUT -j DROP
iptables -P FORWARD DROP
iptables -A FORWARD -j DROP
iptables -P OUTPUT DROP
iptables -A OUTPUT -m state --state ESTABLISHED -j ACCEPT
iptables -A OUTPUT -o lo -j ACCEPT
iptables -A OUTPUT -p udp -d 1.1.1.1 --dport 53 -j ACCEPT
iptables -A OUTPUT -p tcp --dport 443 --syn -j ACCEPT
iptables -A OUTPUT -p tcp --dport 80 --syn -j ACCEPT
iptables -A OUTPUT -p udp --dport 123 -j ACCEPT
iptables -A OUTPUT -j DROP