防火墙
==================

.. code-block:: shell

   # 查看防火墙状态
   systemctl status firewalld

   # 开启防火墙
   systemctl start firewalld

   # 关闭防火墙
   systemctl stop firewalld

   # 开机自启
   systemctl enable firewalld

   # 禁止开机自启
   systemctl disable firewalld

   # 配置防火墙规则
   firewall-cmd --zone=public --add-port=22/tcp --permanent
   firewall-cmd --reload