LinuxCentos-7开、关防火墙。（临时开、关与永久开、关）

1.查看防火墙状态

systemctl status firewalld

2.临时开启防火墙

systemctl start firewalld

3.临时关闭防火墙

systemctl stop firewalld

4.重启防火墙

systemctl restart firewalld

5.永久开启防火墙

systemctl enable firewalld

6.永久关闭防火墙

systemctl disable firewalld

7.查看防火墙是否永久关闭

systemctl is-enabled firewalld