This is an old revision of the document!
Table of Contents
IMPORTANT
You must ensure that your profile on the CHPC User Portal has your institution or company email address.
Generic email addresses (e.g., Gmail, Yahoo, etc.) are no longer accepted as the primary email address for your account.
As a result, users currently registered with personal email addresses have been temporarily blocked from accessing Lengau until their email address is updated.
What you need to do:
- Log in to the CHPC User Portal as normal.
- If your account uses a personal email address, you will be prompted immediately to update it.
- Enter your valid institutional or company email address.
- Once validated, the MFA page will appear and a verification code will be sent to your new email address.
- Enter the verification code to complete login.
Note: Your password has not changed. If you have forgotten your password, please use the password reset option. The reset instructions will be sent to your insitutional registered email address.
After successfully updating your email, access to Lengau will be restored within 24 hours.
Logging into the Lengau cluster
As of 20 June 2026, the Lengau login procedure has been made much more secure. There are three layers of security:
- Multi-factor authentication on the user portal
Process
This is the process for logging into Lengau for the first time once services have been restored:
- Login to the CHPC User Portal using your username and password.
- Complete MFA verification using the 6-digit code sent to your email (valid for 2 hours).
- Configure and download your unique VPN profile, then connect to the CHPC VPN.
- Create your SSH keys (if none exist) and copy the contents of public key to a text file.
- Load the contents of the public key file onto the cluster through the ssh-keys management page on the user portal.
- SSH to Lengau using your CHPC username. If you have not loaded the keys at the previous step, you will be prompted to do so now at the login prompt.
The process is demonstrated in this video.
Frequently Asked Questions
Before asking for help, please take a look at our Login FAQ
Multi-factor authentication on the user portal
Users manage their profile data on the CHPC user portal. To protect the integrity of the cluster login credentials as well as private information, logging into this web-based user portal will require the user to enter a 6-digit code which will be sent automatically to their registered email address. Contact the CHPC helpdesk immediately if you notice such any such email not triggered by yourself.
Virtual Private Network into the CHPC network
A VPN is used to restrict access to the CHPC network to registered CHPC users. In addition, each registered user may have only one open VPN connection at any given time. Get your WireGuard configuration file on the CHPC user portal. Additional client software install instructions are available on the WireGuard web page.
For more information see the CHPC VPN guide.
Checklist
If you are experiencing difficulties, work through this checklist:
- Check basic network connectivity
- Check for presence of other VPN connections
- Confirm no other open WireGuard connections on the same configuration file
- Check nature of error message - is this a VPN or ssh failure?
- Check local firewalling on workstation
- Check with IT department that UDP port 51820 is open to vpn.chpc.ac.za
- Check if same workstation and config work on alternative network, such as with cellphone hotspot
- Does
nslookup lengau.chpc.ac.zareturn an IP address? It should be 10.128.15.127 - Try to do an ssh login on 10.128.15.127
- Reboot workstation
- Submit a helpdesk request for assistance
Cluster login by means of ssh-keys only
To increase security without incurring too much unnecessary effort, cluster login is by means of ssh-keys only. Passwords are inherently insecure and easy to get wrong. Ssh-keys are easy to set up and make subsequent logins much easier. The process is explained on this page.
