查看防火墙是否关闭

[root@localhost ~]# firewall-cmd --state
not running
[root@localhost ~]#

开启防火墙

[root@localhost ~]# systemctl start firewalld
[root@localhost ~]# firewall-cmd --state
running

关闭防火墙

[root@localhost ~]# systemctl stop firewalld
[root@localhost ~]# firewall-cmd --state
not running

禁止firewall开机启动

[root@localhost ~]# systemctl disable firewalld
Removed symlink /etc/systemd/system/multi-user.target.wants/firewalld.service.
Removed symlink /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service.
这样设置的话，下次重启开机的时候就会禁止firewall的启动，即关闭状态。

设置firewall开机启动

[root@localhost ~]# systemctl enable firewalld
Created symlink from /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service to /usr/lib/systemd/system/firewalld.service.
Created symlink from /etc/systemd/system/multi-user.target.wants/firewalld.service to /usr/lib/systemd/system/firewalld.service.

参考资料

1. CENTER OS7关闭防火墙：https://www.cnblogs.com/gucb/p/11156935.html