/bin/sh
 
iface='eth0'
 
iptables -F
iptables -X
iptables -Z
 
iptables -P INPUT DROP
iptables -P FORWARD DROP
iptables -P OUTPUT DROP
 
#iptables -A INPUT -m state --state INVALID -j DROP

#USING DIAL-UP? USE HASH (#) on the rule mentioned below: - 
 
#ALLOW DNS UDP
iptables -A INPUT -i $iface -p udp -s 207.230.75.34 --sport 53 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A INPUT -i $iface -p udp -s 207.230.75.50 --sport 53 -m state --state NEW,ESTABLISHED -j ACCEPT
 
iptables -A OUTPUT -o $iface -p udp -d 207.230.75.34 --dport 53 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A OUTPUT -o $iface -p udp -d 207.230.75.50 --dport 53 -m state --state NEW,ESTABLISHED -j ACCEPT

# Here are the rules mentioned below: - you can allow mIRC, FTP, chat rooms balh blah whatever you want
# Add rule will work.
 
#ALLOW LOOPBACK
iptables -A INPUT -i lo -j ACCEPT
iptables -A OUTPUT -o lo -j ACCEPT
 
#ALLOW ICMP OUT AND BACK
iptables -A OUTPUT -o $iface -p icmp -j ACCEPT
iptables -A INPUT -i $iface -p icmp -m state --state ESTABLISHED -j ACCEPT
 
 
#ALLOW SSH
iptables -A INPUT -i $iface -p tcp --dport 22 -m state --state NEW,ESTABLISHED -j ACCEPT
 
#ALLOW FTP
iptables -A INPUT -i $iface -p tcp --sport 21 -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A OUTPUT -o $iface -p tcp --dport 21 -j ACCEPT
 
#ALLOW SFTP
#iptables -A INPUT -i $iface -p tcp --sport 22 -m state --state NEW,ESTABLISHED -j ACCEPT
#iptables -A OUTPUT -o $iface -p tcp --dport 22 -j ACCEPT