MobaXterm authentication issues

If you are having trouble connecting to the Empire AI cluster using MobaXterm, you may see an error similar to:

ssh $USER@beta.empireai.edu
ssh: connect to host beta.empireai.edu port 22: Connection timed out

In some cases, the issue may be related to the authentication method used by the SSH client. Our clusters authenticate users through keyboard-interactive authentication, rather than direct SSH password authentication.

Recommended solution: Use keyboard-interactive authentication

Option 1: Configure MobaXterm

When creating or editing your SSH session in MobaXterm:

1. Open MobaXterm.
2. Select your Empire AI SSH session.
3. Go to the session's Advanced SSH settings.
4. Configure the SSH session to allow or prefer keyboard-interactive authentication.
5. Save the session and reconnect.

Option 2: Change configuration via command line

You can explicitly specify the authentication method when connecting:

ssh -o PreferredAuthentications=keyboard-interactive \
    -o KbdInteractiveAuthentication=yes \
    $USER@alpha1.empire-ai.org

If this works, the issue is likely caused by your SSH client attempting to use password authentication instead of keyboard-interactive.

Option 3: Add the configuration to your SSH config file

To make this setting persistent, add the following to your SSH configuration file:

Host alpha1.empire-ai.org alpha.empire-ai.org
    PreferredAuthentications keyboard-interactive
    KbdInteractiveAuthentication yes

You can then connect normally:

ssh $USER@alpha1.empire-ai.org

Important

If the connection works when explicitly specifying keyboard-interactive, please configure your SSH client to use this authentication method for future connections.