Connecting to Hex over SSH

You can generate a new SSH key on your local machine by following the steps outlined here

1. Open Terminal on Linux or Mac (or Git Bash console for Windows)

2. Paste the text below, replacing the email used in the example with your Lancaster University email address.

   ssh-keygen -t ed25519 -C "your_email@example.com"

   Note: If you are using a legacy system that doesn't support the Ed25519 algorithm, use:

   ssh-keygen -t rsa -b 4096 -C "your_email@example.com"

   This creates a new SSH key, using the provided email as a label.

   When you're prompted to "Enter a file in which to save the key", you can press Enter to accept the default file location. Please note that if you created SSH keys previously, ssh-keygen may ask you to rewrite another key, in which case we recommend creating a custom-named SSH key. To do so, type the default file location and replace id_ALGORITHM with your custom key name.

3. You will be prompted to type a secure passphrase. While passwordless keys will work, they are discouraged and we strongly recommend you set a password at this stage.

   Enter passphrase (empty for no passphrase): [Type a passphrase]

   Enter same passphrase again: [Type passphrase again]

Once these steps complete you should now have id_ALGORITHM.key and id_ALGORITHM.pub files created on your local machine. You should never share your .key file, but you can freely share your .pub key.

If you already have a connection to the university VPN (managed machines should come with this as default) you can directly access this website and any Hex compute node. To do this, simply append the following host definition to your .ssh/config file (Mac/Linux) or %USERPROFILE%\.ssh\config on Windows.

The windows path normally resolves to something roughly approximating C:\Users\username\.ssh\config

Host hex-host-*.scc.lancs.ac.uk
    User YOUR_USERNAME
    Port 6767
    IdentityFile YOUR_PRIVATE_KEY

Once this is in place, you should be able to connect to your assigned Node(s) by typing ssh hex-host-???.scc.lancs.ac.uk where ??? is your assigned node number. This should automatically drop you into a bash terminal session.

If you are not on a university-managed laptop or desktop, or are using your own equipment, you can also connect to the university VPN service by installing the software found here: Lancaster University - Portal - Virtual Private Network (VPN)

If you have an account on the ssh bastion server, you do not need to use the university VPN to connect through to Hex compute nodes, although this site, and its associated domains will not work. Note that the bastion is an SCC managed service, and not technically part of Hex itself, so to request access please contact the SCC Systems Team directly.

To connect, extend the .ssh/config we discussed above with a new entry for the scc-bastion host:

Host scc-bastion
    Hostname scc-bastion.lancs.ac.uk
    Port 6767
    ForwardAgent yes
    User YOUR_USERNAME
    IdentityFile YOUR_PRIVATE_KEY

Host hex-host-*.scc.lancs.ac.uk
    User YOUR_USERNAME
    Port 6767
    IdentityFile YOUR_PRIVATE_KEY
    ForwardAgent yes
    ProxyJump scc-bastion