About Riverbed Cloud Portal : Registering appliances
  
Registering appliances
Auto-registration is the process in which a licensed appliance reports to the Cloud Portal. If a one-time token is installed on the appliance, the portal automatically creates an entry in its database for the appliance. After the appliance is registered, it is listed as a Riverbed Appliance in your portal account.
An appliance can be unregistered by reclaiming its license or by regenerating the one-time token associated with its license.
About one-time tokens
Reclaiming a license.