远程SSH连接Linux的时候怎么也连不上，ping 也是通的，度娘给出了答案，要关闭防火墙，关闭方法
使用tab键切换，space键选定，
┌──────┤ Firewall Configuration ─────
│ │
│ A firewall protects against unauthorized │
│ network intrusions. Enabling a firewall blocks │
│ all incoming connections. Disabling a firewall │
│ allows all connections and is not recommended. │
│ │
│ Security Level: (*) Enabled ( ) Disabled │
│ │
