The vCenter Server Appliance accepts several authentication methods. The authentication method that you choose depends on whether you choose token authentication, and on the state of the appliance.

During normal operation, the vCenter Server Appliance enables you to authenticate with vCenter Single Sign-On credentials. You have the option to use either token authentication or user name and password authentication. The user name and password must be recognized within the vCenter Single Sign-On domain.

However, during the process of restoring the Appliance from a backup image, you must use a different authentication protocol. For more information, see Restoring the vCenter Server Appliance.