Resolving login issues with SSH and OpenOnDemand

When accessing the TU/e Umbrella HPC Cluster, you might encounter login issues. This guide provides a step-by-step approach to resolving them.

1. Ensure you are on the TU/e network

Access to the TU/e Umbrella HPC Cluster requires you to be connected to the TU/e network.

For this you'll need either to be on campus, or connect to TU/e VPN Services.

2. Check the address

Ensure you are using the correct address for accessing the HPC resources.

For OpenOnDemand ensure you're using https://hpc.tue.nl. When using SSH, the command should be similar to one of the following:

ssh USERNAME@hpc.tue.nl
ssh hpc.tue.nl -l USERNAME

# USERNAME needs to be replaced with your actual username (also see: 3. Verify your username)

3. Verify your username

Your username should be your TU/e network name. This is (usually) a numeric ID. Double-check for typos or incorrect capitalization.

4. Verify your password

Make sure you are entering the correct password. This should be the same password you use for other TU/e services (TU/e laptop, Microsoft 365) If you suspect the password might be incorrect:

• Try logging into another TU/e service to confirm it's working.
• If necessary, reset your TU/e password.

5. Check for expired accounts

Typically, Umbrella HPC accounts expire about a year after the initial request and needs periodic renewal to ensure your account remains active. Account renewals can be requested through our Service Portal.

Other

SSH

Fingerprint Mismatch

This applies when you see the following message. Please resolve this warning as soon as possible for your own security and privacy.

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.
The fingerprint for the ED25519 key sent by the remote host is
SHA256:a0EWqBadQrhOezlF5HuhCo/diEBMl1ElskZ4LpNci3c.
Please contact your system administrator.
Add correct host key in ~/.ssh/known_hosts to get rid of this message.
Offending ECDSA key in ~/.ssh/known_hosts:3
Host key for hpc.tue.nl has changed and you have requested strict checking.
Host key verification failed.

Please run the following command to resolve the issue:

ssh-keygen -R hpc.tue.nl

This commands removes the old stored fingerprint from your ~/.ssh/known_hosts file. On next login you'll be prompted to verify and accept the fingerprint. Use the table below to verify the fingerprint.

Do NOT proceed if the fingerprint isn't matching and contact hpcsupport@tue.nl as soon as possible!