查询有哪些端口是开启的:

[root@centos7 ~]# firewall-cmd --list-port

开启端口

[root@centos7 ~]# firewall-cmd --zone=public --add-port=80/tcp --permanent

重启防火墙：

[root@centos7 ~]# firewall-cmd --reload

查询端口号80 是否开启：

[root@centos7 ~]# firewall-cmd --query-port=80/tcp

命令含义：

–zone #作用域
–add-port=80/tcp #添加端口，格式为：端口/通讯协议
–permanent #永久生效，没有此参数重启后失效

关闭firewall：

systemctl stop firewalld.service #停止firewall

systemctl disable firewalld.service #禁止firewall开机启动

二、CentOS6防火墙开放端口：

在我们使用CentOS系统的时候，CentOS防火墙有时是需要改变设置的。CentOS防火墙默认是打开的，设置CentOS防火墙开放端口方法如下：

打开iptables的配置文件：vi /etc/sysconfig/iptables

修改CentOS防火墙时注意：一定要给自己留好后路,留VNC一个管理端口和SSh的管理端口

下面是一个iptables的示例：

Firewall configuration written by system-config-securitylevel

Manual customization of this file is not recommended.

*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:RH-Firewall-1-INPUT - [0:0]
-A INPUT -j RH-Firewall-1-INPUT
-A FORWARD -j RH-Firewall-1-INPUT
-A RH-Firewall-1-INPUT -i lo -j ACCEPT
-A RH-Firewall-1-INPUT -p icmp –icmp-type any -j ACCEPT
-A RH-Firewall-1-INPUT -p 50 -j ACCEPT
-A RH-Firewall-1-INPUT -p 51 -j ACCEPT
-A RH-Firewall-1-INPUT -m state –state ESTABLISHED,RELATED -j ACCEPT
-A RH-Firewall-1-INPUT -m state –state NEW -m tcp -p tcp –dport 53 -j ACCEPT
-A RH-Firewall-1-INPUT -m state –state NEW -m udp -p udp –dport 53 -j ACCEPT
-A RH-Firewall-1-INPUT -m state –state NEW -m tcp -p tcp –dport 22 -j ACCEPT
-A RH-Firewall-1-INPUT -m state –state NEW -m tcp -p tcp –dport 25 -j ACCEPT
-A RH-Firewall-1-INPUT -m state –state NEW -m tcp -p tcp –dport 80 -j ACCEPT
-A RH-Firewall-1-INPUT -m state –state NEW -m tcp -p tcp –dport 443 -j ACCEPT
-A RH-Firewall-1-INPUT -j REJECT –reject-with icmp-host-prohibited
COMMIT