First SSH connection

The following message will appear at your first attempt to connect to allo-psmn:

The authenticity of host 'allo-psmn.ens-lyon.fr (140.77.144.90)' can't be established. 
RSA key fingerprint is xx:lots:of:caracters:ascii:xx:xx.

• To the question:

Are you sure you want to continue connecting (yes/no)?

Answer : yes

Si vous ne disposez pas déjà d'un jeu de clefs SSH sans mot de passe, vous allez le créer la première fois que vous vous connectez (pour simplifier le fonctionnement du système de calculs, vous devez disposer d'un jeu de clefs SSH sans mot de passe). Tapez les lignes de commande suivantes :

ssh-keygen -t dsa

• To the question:

Generating public/private dsa key pair.
Enter file in which to save the key (/home/votrelogin/.ssh/id_dsa) :

Hit ENTER (default answer)

• To the questions :

Enter passphrase (empty for no passphrase) :

and

Enter same passphrase again :

Hit ENTER (default answer)

• Then type:

ssh-keygen -t rsa

• To the question:

Generating public/private rsa key pair.
Enter file in which to save the key (/home/votrelogin/.ssh/id_rsa) :

Hit ENTER (default answer)

• to the questions:

Enter passphrase (empty for no passphrase) :

and

Enter same passphrase again :

Hit ENTER (default answer)

Then, create the ~/.ssh/authorized_keys file by typing:

touch ~/.ssh/authorized_keys

Next, add your public SSH keys (id_?sa.pub) to the ~/.ssh/authorized_keys file:

cat .ssh/id*.pub >> ~/.ssh/authorized_keys

If you already have a pair of SSH authentication keys without password, copy the public key (id_?sa.pub) in ~/.ssh/authorized_keys.

Besides, if you also have a personal pair of SSH authentication keys (with passphrase), you can add your personal SSH public key (id_?sa.pub) to the ~/.ssh/authorized_keys file.

To automate as much as possible connections to machines and compute nodes, create the following configuration file (~/.ssh/config) :

~/.ssh/config

Host *
  ServerAliveInterval 60
  ForwardX11Timeout 1d
  ForwardAgent yes
  ForwardX11 yes         # pour Linux
#  ForwardX11Trusted yes # pour MacOSX
  Compression yes
  StrictHostKeyChecking no

You can find a more complete file on the page Example of SSH configuration.

Moreover, the list of front machine (connection servers) is available at the following page.

Back to SSH connection to front machines