20.7. More Than a Secure Shell
A secure command line interface is just the beginning of the many ways SSH can be used. Given the proper amount of bandwidth, X11 sessions can be directed over an SSH channel. Or, by using TCP/IP forwarding, previously insecure port connections between systems can be mapped to specific SSH channels.
20.7.1. X11 Forwarding
Opening an X11 session over an SSH connection is as easy as connecting to the SSH server using the
-Yoption and running an X program on a local machine.
ssh -Y <user>@example.com
When an X program is run from the secure shell prompt, the SSH client and server create a new secure channel, and the X program data is sent over that channel to the client machine transparently.
X11 forwarding can be very useful. For example, X11 forwarding can be used to create a secure, interactive session of the Printer Configuration Tool. To do this, connect to the server using ssh and type:
After supplying the root password for the server, the Printer Configuration Tool appears and allows the remote user to safely configure printing on the remote system.