Port Forwarding
Port forwarding, also known as tunneling, provides a way to redirect communications through the Secure Shell channel of an active session. When port forwarding is configured, all data sent to a specified port is redirected through the secure channel. You can configure any of the following.
- Local port forwarding moves data securely between an application client running on the Secure Shell client host and a remote application server.
- Remote port forwarding moves data securely between an application client running on the Secure Shell server host and a local application server.
- FTP forwarding allows you to forward all FTP communications through the Secure Shell tunnel.
- X11 forwarding moves X protocol data securely between an X server running on the Secure Shell client host and an X client running on the Secure Shell server host. This is a special category of dynamic remote port forwarding, and is configured using different settings.
Terminology
Port forwarding involves two sets of client and server applications — the Secure Shell client and server, and the client/server pair whose data is being forwarded. In this guide, the following terms are used as defined below in reference to port forwarding:
Term |
Definition |
Secure Shell server |
The Reflection for Secure IT server daemon. |
Secure Shell server host |
The computer on which the Secure Shell server runs. |
Secure Shell client |
The Reflection for Secure IT client application. |
Secure Shell client host |
The computer on which the Secure Shell client runs. |
Application client |
The client program of the client/server pair whose data you want to forward. For example, this might be a mail client or Web browser. |
Application client host |
The computer on which the application client runs. This is often either the Secure Shell server host or the Secure Shell client host, but it can also be a third host. |
Application server |
The server program that communicates with your application client, such as a mail server or Web server. |
Application server host |
The computer on which the server application runs. This can be either the Secure Shell server host or the Secure Shell client host, or it can also be a third host. |
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