putty使用端口转发

Using port forwarding in SSH
The SSH protocol has the ability to forward arbitrary network connections over your encrypted SSH connection, to avoid the network traffic being sent in clear. For example, you could use this to connect from your home computer to a POP-3 server on a remote machine without your POP-3 password being visible to network sniffers.

In order to use port forwarding to connect from your local machine to a port on a remote server, you need to:

Choose a port number on your local machine where PuTTY should listen for incoming connections. There are likely to be plenty of unused port numbers above 3000. (You can also use a local loopback address here; see below for more details.)
Now, before you start your SSH connection, go to the Tunnels panel (see section 4.23). Make sure the ‘Local’ radio button is set. Enter the local port number into the ‘Source port’ box. Enter the destination host name and port number into the ‘Destination’ box, separated by a colon (for example, popserver.example.com:110 to connect to a POP-3 server).
Now click the ‘Add’ button. The details of your port forwarding should appear in the list box.