Remote Access via OpenSSH

Remote access to the Unix Pool facilities are possible via the OpenSSH (Open Secure Shell) protocol. To establish a connection, an SSH client is required. Linux and MacOS installations usually feature an SSH client by default; MS Windows users have to obtain third party software (e.g. PuTTY).

On this page your can find our SSH node addresses. Security-aware users might want to check their fingerprints beforehand (to make sure you are in fact connecting to our server).

SSH Gateways

  • unixpool.math.tu-berlin.de
  • pool.math.tu-berlin.de

Hostkey Fingerprints

RSA Key 
ED25519 Key 

Login Instructions

On Linux and Mac:

Open a terminal emulator and input the following:

  • ssh username@unixpool.math.tu-berlin.de

On MS Windows (using PuTTY):

In the configuration dialogue, set "hostname" to "unixpool.math.tu-berlin.de" and "protocol" to "SSH". We recommend unchecking the "Close Window on Exit" option, as possible error messages might instantly disappear. Clicking "Open" establishes the connection. Enter your username and password as prompted, and the login process should succeed.

Optional: Creating a Pair of Hostkeys

To prevent your account from misuse, you can create a pair of hostkeys (public and private). The public key you can transfer to Unix pool, which lets you become authenticated automatically during future logins.

On Linux and Mac:

Open a terminal emulator and enter the following:

  • ssh-keygen -t rsa -b 4096

The SSH programme should have created two files:

~/.ssh/id_rsa      (private key)
~/.ssh/id_rsa.pub  (public key)

The public key file's content needs to be appended to the authorized keys' file in your Unix Pool accounts' user directory:

  • cat ~/.ssh/id_rsa.pub | ssh anmeldename@unixpool.math.tu-berlin.de 'cat >> .ssh/authorized_keys'

Hint: Securing your keypair with a passphrase is highly recommended.

On MS Windows:

Windows users need a separate application called "PuTTYgen" for host key generation (download link: see above).

When you have created your keys, you can insert your key into your PuTTY-Client under "Connection -> SSH -> Auth". To make your public key known to the Unix Pool servers, please take the following actions:

  • Connect to Unix Pool via PuTTY.
  • Open the file ~/.ssh/authorized_keys with a test editor (for simplicity we recommend "nano"):
    • nano ~/.ssh/authorized_keys
  • In case the file should not yet exist, create it and adjust its permissions:
    • cd ~
    • mkdir ~/.ssh
    • chmod 0700 ~/.ssh
    • touch ~/.ssh/authorized_keys
    • chmod 0644 ~/.ssh/authorized_keys
  • Copy the contents of your public(!) key into this file.
  • Save it and exit "nano":
    • Ctrl+o  ->  Enter
    • Ctrl+x

Hint: Graphical Programmes cannot be executed via SSH under MS Windows. Since graphical applications tend to run very slowly and with great delay anyway, we recommend using x2go for these purposes.