vi /etc/sysconfig/iptables
# Firewall configuration written by system-config-firewall
# Manual customization of this file is not recommended.
*filter
:INPUT DROP [0:0]
:FORWARD DROP [0:0]
:OUTPUT ACCEPT [0:0]
-A INPUT -m state –state ESTABLISHED,RELATED -j ACCEPT
-A INPUT -p icmp -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -i eth0 -p tcp –dport 20:21 -j ACCEPT #vsftpd
-A INPUT -i eth0 -p tcp –dport 22 -j ACCEPT
-A INPUT -i eth0 -p tcp –dport 25 -j ACCEPT #postfix
-A INPUT -i eth0 -p tcp –dport 80 -j ACCEPT
-A INPUT -i eth0 -p tcp –dport 110 -j ACCEPT #postfix
-A INPUT -i eth0 -p tcp –dport 143 -j ACCEPT #postfix
-A INPUT -i eth0 -p tcp –dport 65400:65410 -j ACCEPT #vsftpd
-A INPUT -i eth0 -m state –state RELATED,RELATED -j ACCEPT
-A INPUT -i eth0 -m state –state NEW,INVALID -j DROP
#-A INPUT -m state –state NEW -m tcp -p tcp –dport 22 -j ACCEPT
#-A INPUT -m state –state NEW -m tcp -p tcp –dport 80 -j ACCEPT
#-A INPUT -m state –state NEW -m tcp -p tcp –dport 25 -j ACCEPT
#-A INPUT -m state –state NEW -m tcp -p tcp –dport 110 -j ACCEPT
#-A INPUT -m state –state NEW -m tcp -p tcp –dport 143 -j ACCEPT
#-A INPUT -j REJECT –reject-with icmp-host-prohibited
#-A FORWARD -j REJECT –reject-with icmp-host-prohibited
COMMIT
chkconfig –list |grep iptables
iptables 0:關閉 1:關閉 2:開啟 3:開啟 4:開啟 5:開啟 6:關閉
/etc/rc.d/init.d/iptables start //啟動 iptables 服務
/etc/rc.d/init.d/iptables stop //停止 iptables 服務
/etc/rc.d/init.d/iptables restart //重新啟動 iptables 服務
/etc/rc.d/init.d/iptables status //查看目前 iptables 規則
/etc/rc.d/init.d/iptables save //將目前規則存入 iptables 設定檔