【Linux】Centos7 防火墙命令

1. systemctl status firewalld ：查看防火墙状态
2. systemctl stop firewalld ：关闭防火墙，重启后失效
3. systemctl disable firewalld ：关闭防火墙，重启后仍保持关闭
4. systemctl enable firewalld ：开启防火墙