blog - iptables

#!/bin/bash
# iptables.sh
#

#política por defecto
iptables -P INPUT DROP
iptables -P FORWARD DROP
iptables -P OUTPUT ACCEPT

#
# Flush (-F) all specific rules
#
iptables -F INPUT
iptables -F FORWARD
iptables -F OUTPUT

#Conexiones establecidas
iptables -A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -i lo -j ACCEPT

#ping
iptables -A INPUT -p icmp --icmp-type 8 -m conntrack --ctstate NEW,ESTABLISHED,RELATED -j ACCEPT
iptables -A OUTPUT -p icmp --icmp-type 0 -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT

#SSH
iptables -A INPUT -p tcp --dport ssh -j ACCEPT

#HTTP
iptables -A INPUT -p tcp --dport 80 -j ACCEPT

#FTP
iptables -A INPUT -p tcp --dport 20 -j ACCEPT
iptables -A INPUT -p tcp --dport 21 -j ACCEPT
iptables -A INPUT -p tcp --dport 40110:40210 -j ACCEPT