Configure Port Forwarding

To configure and use local port forwarding

1. Pick a local port to use for forwarding. (This procedure uses 2110 as an example.)

   NOTE:This can be any available port, but don't use port values less that 1024. These ports are, by convention, reserved for services, and may not be available.

2. Configure your application client (for example your e-mail client) to connect to the forwarded port on the local host rather than to the remote application server socket. For this example:

   Forwarded local port	Remote application server socket
   localhost:2110	mailserver.com:110

3. Connect the Secure Shell client.

   Use local port forwarding to send data from the forwarded local port to the remote application server. The general command line syntax is:

   ssh -L listening_port:app_host:hostport user@sshserver

   For this example, the mailserver runs on the same host as the Secure Shell server. The application host in this case is "localhost" on mailserver.com. The command-line configuration is:

   ssh -L 2110:localhost:110 joe@mailserver.com

4. Use the application client as you normally would.

   The data is forwarded securely from the listening port on the client host (localhost:2110) through the secure channel to the remote application server's listening socket on mailserver.com (localhost:110).