There are two probable reasons which can explain the situation.

• You are trying to connect from a machine for which you have not declared the IP address. You must establish your connection via a machine with a declared IP address or request adding the IP address of the machine from which you want to connect by using the FGC form.
  Important: We only accept fixed institutional IP addresses.
  
  
• One time per week, on average, we carry out maintenance operations which are announced on the IDRIS Web site: On the home page, click on the drop-down menu entitled « For users » and then on "Machine availability". It is generally not possible to connect during these maintenance sessions.

Apart from one of these problems, please contact the User Support Team () and include what the ssh -vvv … command displays.