力登console交换机登录设备console口的方法：
命令1：connect + console交换机的端口号
命令2：退出设备console口，使用Control-]，再quit一下，就退出来初始状态
admin > connect 40
Authentication successful.
Escape Sequence is: Control-]
You are now master for the port.
admin:Port40:PortCommand>
clearhistory Clear history buffer for this port.
close Close this target connection.
gethistory Display the history buffer for this port.
getwrite Get write access for the port.
history Display the current session's command line history
powerstatus Query Power status of this port
powertoggle Toggle Power On/Off of this port
q Close this target connection.
quit Close this target connection.
return Return to the target session.
sendbreak Send a break to the connected target.
writelock Lock write access to this port.
writeunlock Unlock write access to this port.
admin:Port40:PortCommand> quit
Closing serial console session.
admin >
admin >
