iptables-sample.sh

#!/bin/sh

# Reset Firewall
iptables -t filter -F
iptables -t filter -X
# Bloquage total
iptables -t filter -P INPUT DROP
iptables -t filter -P OUTPUT DROP
iptables -t filter -P FORWARD DROP
# Ne pas casser les connexions
iptables -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
iptables -A OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
# Autorise le loopback (127.0.0.1)
iptables -t filter -A INPUT -i lo -j ACCEPT
iptables -t filter -A OUTPUT -o lo -j ACCEPT
echo "Loopback"
# ICMP (le ping)
iptables -t filter -A INPUT -p icmp -j ACCEPT
iptables -t filter -A OUTPUT -p icmp -j ACCEPT
echo "Ping ok"
# SSH IN/OUT
iptables -t filter -A INPUT -p tcp --dport 1602 -j ACCEPT
iptables -t filter -A OUTPUT -p tcp --dport 1602 -j ACCEPT
echo "SSH ok"
# DNS In/Out
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
echo "dns ok"
# NTP Out
iptables -t filter -A OUTPUT -p udp --dport 123 -j ACCEPT
echo "ntp ok"
# HTTP + HTTPS Out
iptables -t filter -A OUTPUT -p tcp --dport 80 -j ACCEPT
iptables -t filter -A OUTPUT -p tcp --dport 443 -j ACCEPT
# HTTP + HTTPS In
iptables -t filter -A INPUT -p tcp --dport 80 -j ACCEPT
iptables -t filter -A INPUT -p tcp --dport 443 -j ACCEPT
iptables -t filter -A INPUT -p tcp --dport 8443 -j ACCEPT
echo "http ok"
# FTP Out
iptables -t filter -A OUTPUT -p tcp --dport 21 -j ACCEPT
iptables -t filter -A OUTPUT -p tcp --dport 20 -j ACCEPT
# FTP In
# imodprobe ip_conntrack_ftp # ligne facultative avec les serveurs OVH
iptables -t filter -A INPUT -p tcp --dport 20 -j ACCEPT
iptables -t filter -A INPUT -p tcp --dport 21 -j ACCEPT
iptables -t filter -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
echo "ftp ok"
# Mail SMTP:25
iptables -t filter -A INPUT -p tcp --dport 25 -j ACCEPT
iptables -t filter -A OUTPUT -p tcp --dport 25 -j ACCEPT
# Mail POP3:110
iptables -t filter -A INPUT -p tcp --dport 110 -j ACCEPT
iptables -t filter -A OUTPUT -p tcp --dport 110 -j ACCEPT
# Mail IMAP:143
iptables -t filter -A INPUT -p tcp --dport 143 -j ACCEPT
iptables -t filter -A OUTPUT -p tcp --dport 143 -j ACCEPT
# Mail POP3S:995
iptables -t filter -A INPUT -p tcp --dport 995 -j ACCEPT
iptables -t filter -A OUTPUT -p tcp --dport 995 -j ACCEPT
echo "mail ok"
# Monit
iptables -t filter -A INPUT -p tcp --dport 4598 -j ACCEPT
# Webmin
iptables -t filter -A INPUT -p tcp --dport 10000 -j ACCEPT
echo "monitoring ok"