Remote access and logging in




Access to Research Computing resources is available over the campus network and the general Internet largely by way of the Secure Shell, or ssh, protocol. Access is provided via one of the dedicated login nodes.

When you have logged into an RC login node, you are accessing one of several virtual machines on which you can edit files, submit jobs to the compute clusters, and access storage resources. Use of the login nodes should be restricted to editing, data transfer, and job submission. Running CPU- or memory-intensive processes on the login nodes is actively discouraged because doing so is likely to impact other users' work. Data analysis and large-scale data transfers should be done via scheduled jobs. Software compilation is best done on the targeted resource via an interactive job or (for applications that are meant to run on Summit) on one of the Summit compile nodes.

The secure shell (ssh)

Once you have

  • obtained a Research Computing account;

and

  • obtained, registered, and tested an OTP authenticator;
  • or registered with Duo

you should be able to log into an RC login node using the secure shell (ssh).

The ssh command can be run from the Linux and OS X command-line.

ssh -l rc_username login.rc.colorado.edu

where you should replace rc_username with your actual Research Computing username.

When logging in from Windows, we recommend the PuTTY application.

The first time you log in, the system will configure your internal ssh key pair, used for authentication between internal hosts.

Attempting to create internal ssh config for connecting to
CURC managed resources...  Generating public/private rsa key pair.
Your identification has been saved in /home/example/.ssh/curc.
Your public key has been saved in /home/example/.ssh/curc.pub.
The key fingerprint is:
ed:43:02:88:99:10:d5:87:ed:84:51:b1:69:73:24:b4
example@login01.rc.colorado.edu

Further reading

The ssh protocol and its related applications have many features. It can be used as simply as described here, to provide simple shell access to the RC login nodes; but it can also

  • transfer files,
  • forward X11 GUI application interfaces,
  • proxy TCP connections,
  • multiplex sessions through a single connection,

and much more.

If you are interested in using advanced ssh features, we recommend the following additional reading: