iptables를 이용한 방화벽 설정 예

#!/bin/sh
#ssh
iptables -A INPUT -p tcp --dport 22 -j ACCEPT

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

#pop3
iptables -A INPUT -p tcp --dport 110 -j ACCEPT

#imap
iptables -A INPUT -p tcp --dport 143 -j ACCEPT

#smtp
iptables -A INPUT -p tcp --dport 25 -j ACCEPT

#ftpd
iptables -A INPUT -p tcp --dport 21 -j ACCEPT

#ftp-data
iptables -A INPUT -p tcp --dport 20 -j ACCEPT

#samba
iptables -A INPUT -p tcp --dport 139 -j ACCEPT

#dns
iptables -A OUTPUT -p udp --destination-port 53 -j ACCEPT
iptables -A INPUT -p udp --source-port 53 -j ACCEPT
iptables -A OUTPUT -p tcp --destination-port 53 -j ACCEPT
iptables -A INPUT -p tcp --source-port 53 -m state --state ESTABLISHED,RELATED -j ACCEPT

# drop
iptables -A INPUT -p tcp --dport 1:30000 -j DROP
iptables -A INPUT -p icmp --icmp-type echo-request -j DROP

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#samba 2월 3일에 추가