查看防火墙状态：systemctl status firewalld.service
关闭防火墙：systemctl stop firewalld.service
开启防火墙：systemctl start firewalld.service
关闭开机防火墙自启动：systemctl disable firewalld
开启开机防火墙自启动（enabled状态）：systemctl enable firewalld
查看开机是否启动：
先执行：chkconfig --list | grep network
会提示服务查看命令，即'systemctl list-unit-files'
