#!/bin/bash

eth0='eno16777728'

iptables -P INPUT ACCEPT
iptables -P FORWARD ACCEPT
iptables -P OUTPUT ACCEPT
iptables -F
iptables -X
iptables -t nat -F
iptables -t nat -X
iptables -t mangle -F
iptables -t mangle -X

iptables -F
iptables -P INPUT DROP
iptables -P OUTPUT DROP
iptables -P FORWARD DROP

iptables -A OUTPUT -o lo -j ACCEPT
iptables -A INPUT -s 192.168.0.0/24 -j DROP

iptables -A INPUT -p icmp --icmp-type echo-request -j ACCEPT
#always
iptables -A OUTPUT -p icmp --icmp-type echo-reply -m state --state ESTABLISHED,RELATED -j ACCEPT

iptables -A OUTPUT -p icmp --icmp-type echo-request -j ACCEPT
iptables -A INPUT -p icmp --icmp-type echo-reply -m state --state ESTABLISHED,RELATED -j ACCEPT

#3
iptables -A OUTPUT -p udp --dport 53 -j ACCEPT
iptables -A INPUT -p udp --sport 53 -m state --state ESTABLISHED,RELATED -j ACCEPT


#4
iptables -A INPUT -p tcp --dport 22 -j ACCEPT
iptables -A OUTPUT -p tcp --sport 22 -m conntrack --ctstate ESTABLISHED -j ACCEPT

#5
iptables -A OUTPUT -p tcp --sport 1024: --dport 21 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
iptables -A INPUT -p tcp --sport 21 -m conntrack --ctstate ESTABLISHED -j ACCEPT

iptables -A OUTPUT -p tcp --sport 1024: --dport 1024: -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
iptables -A INPUT -p tcp --sport 1024: -m conntrack --ctstate ESTABLISHED -j ACCEPT

#6.1
iptables -A OUTPUT -p tcp --match multiport --dport 80,443 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
iptables -A INPUT -p tcp --match multiport --sport 80,443 -m conntrack --ctstate ESTABLISHED -j ACCEPT

#6.2
iptables -A INPUT -p tcp --match multiport --dport 80,443 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
iptables -A OUTPUT -p tcp --match multiport --sport 80,443 -m conntrack --ctstate ESTABLISHED -j ACCEPT