Connecting to Linux Computers Via SSH

You can remotely login to CS department Linux computers using an SSH client. Use of the Department VPN is encouraged for added security and is required to access certain internal networks protected from connections originating outside the Computer Sciences Department.

Note: Due to the authentication requirements of the AFS flle system, you can not use SSH Public Key authentication.

SSH clients

Macintosh and Linux computers typically come with an SSH client. There are several SSH implementations available for Windows computers including PuTTY and SecureCRT . PuTTY is an open-source product available to anyone at no charge. SecureCRT is a commercial SSH product licensed by the UW-Madison campus for students, faculty and staff at no charge through the Campus Software Library; that site can be accessed via http://software.wisc.edu

X-window display

Users who want a graphical display to use in conjuction with their SSH client will need to have an X-server installed on the computer where they want to display X-window based output. Linux and Macintosh computers typically have an X-window display available on them. Windows users can download and install Xming for this purpose.

The Windows-based SSH clients will need to have X11 forwarding or tunnelling enabled to display X-window based GUI applications. Linux and Macintosh clients may need to be invoked with the -X (upper-case X, not lower-case) to enable X11 forwarding/tunnelling. Display environment variables on the remote Linux computer should be set automatically when the X11 forwarding/tunnelling option is enabled.

VSCode in the CS environment

When using VSCode with the default settings, you may experience issues with the Remote SSH extension. This occurs due to an adverse interaction with AFS and may be resolved by navigating to Settings and ensure sure following option is checked:

Remote.SSH: Lockfiles in Tmp

New versions of VSCode use a different Remote-SSH bootstrapping method that may cause problems with connections. If Remote.SSH: Lockfiles in Tmp is already set, uncheck the following option:

Remote.SSH: Use Exec Server

If you are still experiencing issues even after making the above configuration change, please try resetting all settings to default and then making the above changes again.