[root@localhost ~]# vi /etc/sysconfig/iptables

正确的配置文件

# Firewall configuration written by system-config-firewall

# Manual customization of this file is not recommended.

*filter

:INPUT ACCEPT [0:0]

:FORWARD ACCEPT [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 -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 -j REJECT –reject-with icmp-host-prohibited

-A FORWARD -j REJECT –reject-with icmp-host-prohibited

COMMIT

-A INPUT -m state –state NEW -m tcp -p tcp –dport * -j ACCEPT

注意点：新开放的端口一定要在端口22后面
重启防火墙使配置生效

[root@localhost ~]# /etc/init.d/iptables restart

其它
查看开放端口

[root@localhost ~]# /etc/init.d/iptables status

关闭防火墙

[root@localhost ~]# /etc/init.d/iptables stop