引言：Centos 7是目前非常流行的Linux发行版本，本文将重点介绍如何来使用firewalld相关命令启动服务以及添加服务或者端口等操作。

1. 查看firewall服务状态

>> systemctl status firewalld

[root@flybird ~]# systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
   Active: inactive (dead)

2. 启动/关闭firewall

>> systemctl start/stop firewalld

[root@flybird ~]# systemctl start firewalld
[root@flybird ~]# systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
   Active: active (running) since Fri 2016-12-02 23:17:09 CST; 11s ago
 Main PID: 1279 (firewalld)
   CGroup: /system.slice/firewalld.service
           └─1279 /usr/bin/python -Es /usr/sbin/firewalld --nofork --nopid

3. 禁用或者启用firewall

>> systemctl disable/enable firewalld

4. 查看端口是否开放

>>> firewall-cmd --query-port=8020/tcp

5. 新增开发端口

>> firewall-cmd --add-port=5000/tcp --permanent

[root@flybird ~]# firewall-cmd --query-port=5000/tcp
no
[root@flybird ~]# firewall-cmd --add-port=5000/tcp --permanent
success

>> firewall-cmd --add-service=ftp --permanent

>> firewall-cmd --remove-service=ftp --permanent

7. 查看firewall状态

>> firewall-cmd --status

>> systemctl status firewalld

8. 查看 firewall目前开放的内容

>> firewall-cmd --list-all

[root@flybird ~]# firewall-cmd --list-all
public (default)
  interfaces: 
  sources: 
  services: dhcpv6-client http ssh
  ports: 443/tcp 80/tcp 3306/tcp 6739/tcp 10051/tcp 10050/tcp
  masquerade: no
  forward-ports: 
  icmp-blocks: 
  rich rules: 

>> firewall-cmd --list-port

10. 查看firewall-cmd命令的使用说明

>> firewall-cmd --help