Connection from outside of the ENS network

WARNING : Only for your fisrt connection to the allo-psmn node (whether when connecting from the ENS network of from outside), follow these instructions

To connect with SSH from outside the ENS network, you must use one of the SSH servers of the institution:

  • The if you have an informatic account at ENS de Lyon,
  • Or the server (see infographic):

Legend :

  • black : physical link
  • blue : standard SSH connection
  • red : virtual SSH connection (hop)
  • green : NFS links (/home)

Connection from outside of the ENS network

Use the following command:

  • WITH your ENS de Lyon account, via

Your SSH access to , need to be ACTIVATED, see the ENS documentation.

ssh -X -oProxyCommand="ssh netcat -w1 allo-psmn %p"

Then, you must give your password twice.'s password :
yourlogin@allo-psmn's password :
  • WITHOUT a ENS de Lyon account, via
The server is a minimalistic gateway without access to your /home directory at PSMN. You only have enough space to copy your SSH public key and some configuration files (ssh/config, alias, …).

Two-steps connection:

ssh's password :
$ ssh
yourlogin@allo-psmn's password :

One-step connection:

ssh -X -oProxyCommand="ssh netcat -w1 allo-psmn %p"

Then, you'll have to give your password twice:

yourlogin@ssh.psmn's password :
yourlogin@allo-psmn's password :

and you are connected to allo-psmn :


Once connected to allo-psmn, you have access to your PSMN home-directory and to your files.

warning, allo-psmn is a connection server, it allows you to access and transfer your files but that's it
To work oon PSMN cluster you have to connect from allo-psmn, to one of the front nodes

To do so, use the following command:

ssh -X front_node_name

where front_node_name is the name of one of the front nodes.

Use SSH keys and/or SSH agent

You can simplify your usage of SSH commands by using a set of keys, an SSH agent and a suitable configuration (see this documentation) and this example configuration file).

If you have a set of SSH keys (personal, with passphrase), you can add your public key (id_? to the ~/.ssh/authorized_keys file.

  • for (home local)
scp ~/.ssh/
cat .ssh/ >> .ssh/authorized_keys
  • for allo-psmn (home PSMN)
scp ~/.ssh/ yourlogin@allo-psmn:~/.ssh/
ssh yourlogin@allo-psmn
cat .ssh/ >> .ssh/authorized_keys

Want more ?

en/documentation/tutorials/ssh/externe.txt · Dernière modification : 2020/08/25 17:58 de