First SSH connection

• To connect to allo-psmn from the ENS network, simply type in a terminal the following command:

ssh <mylogin>@allo-psmn.psmn.ens-lyon.fr

• To connect to allo-psmn from outside of the ENS network, you first need to connect to ssh.psmn.ens-lyon.fr in order to access the ENS network. Then connect to allo-psmn. In a terminal, type the following commands:

ssh <mylogin>@ssh.psmn.ens-lyon.fr
# enter your PSMN password
# then 
ssh <mylogin>@allo-psmn.psmn.ens-lyon.fr
# enter your PSMN password

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

If you don't have already a SSH key pair without passphrase, you need to create it first time you connect (In order to simplify the computation system, you must have a PSMN's SSH key pair without passphrase). Strictly follow these CLI instructions:

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 key (id_rsa.pub) to the ~/.ssh/authorized_keys file:

cat .ssh/id_rsa.pub >> ~/.ssh/authorized_keys

If you already have a pair of SSH authentication keys without password, copy the public key (id_rsa.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_rsa.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
  TCPKeepAlive yes
  ForwardAgent yes
  ForwardX11 yes         # for Linux
#  ForwardX11Trusted yes # for MacOSX
  Compression yes
  StrictHostKeyChecking no
  HashKnownHosts 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