Debugging Connection Problems¶

When you encounter problems with the login to the cluster although we indicated that you should have access, depending on the issue, here is a list of how to solve the problem:

I'm getting a "connection refused"¶

The full error message looks as follows:

ssh: connect to host hpc-login-1.cubi.bihealth.org port 22: Connection refused

This means that your computer could not open a network connection to the server.

HPC 4 Research can be connected to from:
- Charite (cabled) network
- Charite VPN but only with Zusatzantrag B.
- MDC (cabled) network
- MDC VPN
- BIH (cabled) network
If you think that there is no problem with any of this then please include the output of the following command in your ticket (use the server that you want to read instead of <DEST>):
- Linux/Mac
```
ifconfig
traceroute <DEST>
```
- Windows
```
ipconfig
tracepath <DEST>
```

I can connect, but it seems that my account has no access yet¶

You're logging into BIH HPC cluster! (login-1)

 ***Your account has not been granted cluster access yet.***

 If you think that you should have access, please contact
 hpc-helpdesk@bih-charite.de for assistance.

 For applying for cluster access, contact hpc-helpdesk@bih-charite.de.

user@login-1's password:

Hint

This is the most common error, and the main cause for this is a wrong username. Please take a couple of minutes to read the What is my username?!

If you encounter this message although we told you that you have access and you checked the username as mentioned above, please write to hpc-helpdesk@bih-charite.de, always indicating the message you get and a detailed description of what you did.

I'm getting a passPHRASE prompt¶

You're logging into BIH HPC cluster! (login-1)

 *** It looks like your account has access. ***

 Login is based on **SSH keys only**, if you are getting a password prompt
 then please contact hpc-helpdesk@bih-charite.de for assistance.

Enter passphrase for key '/home/USER/.ssh/id_rsa':

Here you have to enter the passphrase that was used for encrypting your private key. Read SSH Basics for further information of what is going on here.

I can connect, but I get a passWORD prompt¶

You're logging into BIH HPC cluster! (login-1)

 *** It looks like your account has access. ***

 Login is based on **SSH keys only**, if you are getting a password prompt
 then please contact hpc-helpdesk@bih-charite.de for assistance.

user@login-1's password:

This is diffeerent from passPHRASE prompt

Please see I'm getting a passPHRASE prompt for more information.

When you encounter this message during a login attempt, there is an issue with your SSH key. In this case, please connect with increased verbosity to the cluster (ssh -vvv ...) and mail the output and a detailed description to hpc-helpdesk@bih-charite.de.

If you're using macOS and run into problems that your key is not accepted when connecting, please make sure that you're SSH key is properly unlocked in your SSH agent.