Connecting to ARC clusters

Connecting to ARC

Access to ARC systems (including arcus-htc and arcus-b) is via Secure SHell (SSH). 

Linux and Mac (and other Unix/Unix-like systems)

Linux/Mac users should use ssh (secure shell) to connect to the ARC systems from a terminal . 

To connect to the ARC cluster:

ssh -X 

To connect to the HTC cluster:

ssh -X

If you are connecting from outside the univeristy network (or from the VPN service)  you need to connectvia - ensure you specify your ARC username in the ssh command, as shown below: 

ssh -X 

You can then SSH to arc-login or htc-login as required.

Note: The above examples include the -X option which allows the tunnelling of X11 graphics from the cluster to your local machine. This is optional.

However, if you do require graphics, an X11 server needs to be running on your local machine. For Linux this is typically part of the installation - however on a Mac you may need to install an X11 server such as Xquartz.


Windows users will need to download and install an application that allows them to use ssh - a great example is MobaXterm.

Download MobaXterm here.



Please note: Access to ARC machines is only from within the University of Oxford network. If you are not on the University network, you should use the University VPN service to connect. If you are unable to use the VPN service, you may be able to register your static IP with the ARC team ( to enable access.

How do I copy data to/from ARC?

MacOS (terminal) and Linux users can use scp (secure copy) or secure file transfer protocol (sftp).

Windows users can use MobaXterm.

How do I change my password?

Passwords can be changed by running the "passwd" command from a terminal:

user@arc-login~$ passwd Enter login(LDAP) password:

Enter new passwd:

Re-enter new passwd:

If you need to change other things in your account (e.g. email address), this is possible - please ask the ARC team by emailing