Compute Canada

How do I use a "secure shell"?

Please note: The FAQ pages at the HPCVL website are continuously being revised. Some pages might pertain to an older configuration of the system. Please let us know if you encounter problems or inaccuracies, and we will correct the entries.

A secure shell (ssh) is a connection protocol that allows logging into a remote machine with an encrypted data stream. This makes it virtually impossible for third parties to "eavesdrop" and gain access to information such as passwords or transfered data. The command associated with a secure shell is ssh.

The use of secure software for interactive login and data transfer is HPCVL user policy, and therefore mandatory. Unencrypted protocols such as telnet or ftp are disabled, i.e. we do not supply a server for them.

Most Unix system include ssh and it's file-transfer equivalent sftp. To log into our system using ssh, simply type
ssh -X username@sfnode0.hpcvl.queensu.ca
where username is your login ID. The -X has the effect of enabling the forwarding of graphics, thus making the explicit setting of a DISPLAY environment variable unnecessary, and encrypting the data stream associated with the graphics as well. This "X11 forwarding" can usually be enabled in the configuration of the whole ssh client.

There is a variety of terminal programs that offer ssh for Windows PC's. One of them is called PuTTY and is available for free. It is a simple program that works on all Windows system reliably. Note that if you use a Windows machine to log in you will also need a XWin emulator program such as Xwin32 to display graphics on your desktop.