查看看防火墙状态
systemctl status firewalld
开启防火墙
service firewalld start
关闭防火墙
service firewalld stop
重启防火墙
service firewalld restart
看防火墙规则
firewall-cmd --list-all
开放端口
firewall-cmd --permanent --add-port=3306/tcp
移除端口
firewall-cmd --permanent --remove-port=3306/tcp
