我使用Windows上的Putty打开了ssh隧道,设置了端口3306,以便从外部网络远程连接到Ubuntu14.04操作系统上的MySql服务器数据库。并且我只在端口3306上得到了以下错误: Failed to add client-to-server port forwarding rule on 127.0.0.1:3306: Address isalready in use; bind () in ListeningSocket :: StartListening () failed: