Secure Shell (ssh)

What is Secure Shell (ssh)

Secure shell is the usual way to gain shell access to CHPC Linux based systems, such as the HPC clusters. There are many choices of clients available depending on the system you are using to connect. We require ssh to connect as it encrypts the connection and is much more secure than other methods of command-line login.

We strongly encourage the use of FastX as the method of choice to access CHPC resources.

Native ssh clients on Linux and Mac

If you are connecting to CHPC services from a Linux desktop or a Mac, you already have a native client. If you are not familiar with ssh, you might wish to look through an SSH Tutorial for Linux or you can also read the "man" page (type "man ssh" in your terminal window). A short training video also mentions SSH.

The steps are simple. 1) Open a terminal on your desktop or laptop; 2) execute the "ssh" command to the host. For example, to ssh into kingspeak:

ssh <uNID>@kingspeak.chpc.utah.edu

If you are going to be opening any XWindows applications, be sure to add the -Y flag to make sure X-forwarding is enabled.   That would look like:

ssh -Y <uNID>@kingspeak.chpc.utah.edu

Windows Clients

Windows has a built-in SSH client in Windows 10 and later. More information is available on Microsoft's documentation. You may need to enable the "OpenSSH Client" ("OpenSSH Server" is not necessary for connecting to remote hosts). Once enabled, you can use SSH by running the commands in the above section from the Command Prompt or PowerShell (recommended).

Alternatively, there are many third-party SSH clients for Windows, including FastX, described above. There are many free clients available. Options include

• PuTTY
  • You also need an X server like Xming if you want to use X forwarding
• Xshell
• MobaXterm
  • To connect to the redwood cluster with MobaXterm, you will need to make a few changes:
    • Check the "Specify username" box and enter your uNID under "Basic SSH settings"
    • Change "SSH-browser type" to "None" under "Advanced SSH settings"
    If you do not change the "SSH-browser type," you may have issues with two-factor authentication.

Graphical SSH clients like those listed above will ask for a hostname. Put in the hostname of the Linux client you are trying to connect to, and put your campus uNID in the "Username" field. If you plan to run applications with graphical interfaces on our server, you will need to find the setting for "X forwarding" and make sure it is checked. Finally, you "connect," which will prompt you for a password and will open up a command line terminal.