Using SFTP

Sftp is an interactive file transfer program, similar to ftp, which performs all operations over an encrypted transport. Sftp is a part of Ssh. sftp connects and logs into the specified host, then enters an interactive command mode.

Caveats:

• Sftp access is only supported for client computers correctly registered in the DNS
• Ssh version 1 is not supported.
• External users must use a special port number (see below).

For the Windows-based personal computers, two programs are available for download, PuTTY and SSH:

• Download PuTTY small, simple and directly executable ssh-client program
• Download SSH full-featured ssh-client program from ssh.com, non-commercial use only, executable file which is an installer program
• How to setup SSH (above client from ssh.com)

From the external side (external users having an user account on an internal system)

Users first connect to a "proxy" server running on the firewall computer, which will in turn automatically connect them to the destination system. To use the Ssh/Sftp proxy, simply sftp to the firewall computer as if you wished to ftp into it, indicating the port number depending on the target Institute (-oPort= option for a UNIX/Linux command, or selected in menus on a graphical interface):

• port 5022 on firewall.esrf.fr: login ESRF (NICE cluster)
• port 5023 on firewall.ill.fr: login ILL
• port 5024 on firewall.embl-grenoble.fr: login EMBL-Grenoble

There will be a short pause, and you will be prompted with a password prompt directly on the internal Ssh/Sftp server.

The external user must have a valid user account (identified by a username and a password) on this Ssh/Sftp server.

• Unix example:

  % sftp -oPort=5022 johnson@firewall.esrf.fr
  Connecting to firewall.esrf.fr...
  johnson@firewall.esrf.fr's password:  XXXXX (password on the Ssh/Sftp server)
  sftp> dir
  img1.gif
  img2.gif
  img3.gif
  .
  .
  (usual ftp commands: dir, cd, ls, get, put...)
  .
  .
  sftp> quit
  % 
  

From inside

Internal users should not cross the firewall for Sftp access, just sftp directly to the remote host. Note that outgoing Sftp is fully supported provided a Sftp client program is used internally (e.g. on the NICE cluster at the ESRF).