Centos7关于防火墙的命令：

firewall-cmd --state  #查看防火墙
systemctl status firewalld #查看防火墙
systemctl stop firewalld #临时关闭防火墙
systemctl start firewalld #临时打开防火墙
systemctl disable firewalld #开机禁止启动防火墙
systemctl enable firewalld #开机启动防火墙