SSH

Passwordless SSH

To set up passwordless SSH, there are three main things to do:

• generate a pair of public/private keys on your local computer
• copy the public key from the source computer to the target computer's authorized_keys file
• check the permissions.

You can repeat that transitively for "A->B->C". You can use the initial pair of keys everywhere.

See here for details:

http://www.stearns.org/doc/ssh-techniques.current.html

Making a cascade of SSH connections easy

Here is a very convenient way to set up the access to any machine directly instead of doing a cascade of SSH calls. Put this into your .ssh/config file :

Host csserver
  User kdichev
  Hostname csserver.ucd.ie
Host heterogeneous
  User kiril
  Hostname heterogeneous.ucd.ie
  ProxyCommand ssh -qax csserver nc %h %p

Since the installation of a new PBS system, you can not directly log into a hclXX node. You can do

ssh heterogeneous

instead and use "qsub"

X11 forwarding

ssh -X hostname