二、安装iptables防火墙

yum install iptables-services //安装
vi /etc/sysconfig/iptables //编辑防火墙配置文件

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
//在此处下面编辑，添加80、3306、8080等端口
-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 3306 -j ACCEPT
-A INPUT -m state --state NEW -m tcp -p tcp --dport 8080 -j ACCEPT

-A INPUT -j REJECT --reject-with icmp-host-prohibited

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

:wq! //保存退出

systemctl restart iptables.service //最后重启防火墙使配置生效
systemctl enable iptables.service //设置防火墙开机启动

CentOs7安装配置Iptables防火墙

原文：http://blog.51cto.com/372550/2064511