iptables

gistfile1.sh

#!/bin/sh 
 
# Réinitialise les règles
iptables -t filter -F 
iptables -t filter -X 
 
# Bloque tout le trafic
iptables -t filter -P INPUT DROP 
iptables -t filter -P FORWARD DROP 
iptables -t filter -P OUTPUT DROP 
 
# Autorise les connexions déjà établies et localhost
iptables -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT 
iptables -A OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT 
iptables -t filter -A INPUT -i lo -j ACCEPT 
iptables -t filter -A OUTPUT -o lo -j ACCEPT 
 
# ICMP (Ping)
iptables -t filter -A INPUT -p icmp -j ACCEPT 
iptables -t filter -A OUTPUT -p icmp -j ACCEPT 
 
# SSH
iptables -t filter -A INPUT -p tcp --dport 22 -j ACCEPT 
iptables -t filter -A OUTPUT -p tcp --dport 22 -j ACCEPT 
 
# DNS
iptables -t filter -A OUTPUT -p tcp --dport 53 -j ACCEPT 
iptables -t filter -A OUTPUT -p udp --dport 53 -j ACCEPT 
iptables -t filter -A INPUT -p tcp --dport 53 -j ACCEPT 
iptables -t filter -A INPUT -p udp --dport 53 -j ACCEPT 
 
# HTTP
iptables -t filter -A OUTPUT -p tcp --dport 80 -j ACCEPT 
iptables -t filter -A INPUT -p tcp --dport 80 -j ACCEPT 
iptables -t filter -A OUTPUT -p tcp --dport 443 -j ACCEPT 
iptables -t filter -A INPUT -p tcp --dport 443 -j ACCEPT 

#HTTPS
iptables -t filter -A OUTPUT -p tcp --dport 443 -j ACCEPT 
iptables -t filter -A INPUT -p tcp --dport 443 -j ACCEPT 

# FTP 
iptables -t filter -A OUTPUT -p tcp --dport 20:21 -j ACCEPT 
iptables -t filter -A INPUT -p tcp --dport 20:21 -j ACCEPT 

# Mail SMTP 
iptables -t filter -A INPUT -p tcp --dport 25 -j ACCEPT 
iptables -t filter -A OUTPUT -p tcp --dport 25 -j ACCEPT 
 
# Mail POP3
iptables -t filter -A INPUT -p tcp --dport 110 -j ACCEPT 
iptables -t filter -A OUTPUT -p tcp --dport 110 -j ACCEPT 
 
# Mail IMAP
iptables -t filter -A INPUT -p tcp --dport 143 -j ACCEPT 
iptables -t filter -A OUTPUT -p tcp --dport 143 -j ACCEPT 

# NTP (horloge du serveur) 
sudo iptables -t filter -A OUTPUT -p udp --dport 123 -j ACCEPT

iptables -A FORWARD -p tcp --syn -m limit --limit 1/second -j ACCEPT