Each vCenter Single Sign-On identity source is associated with a domain. vCenter Single Sign-On uses the default domain to authenticate a user who logs in without a domain name. Users who belong to a domain that is not the default domain must include the domain name when they log in.

When a user logs in to a vCenter Server system from the vSphere Client, the login behavior depends on whether the user is in the domain that is set as the default identity source.

  • Users who are in the default domain can log in with their user name and password.
  • Users who are in a domain that has been added to vCenter Single Sign-On as an identity source but is not the default domain can log in to vCenter Server but must specify the domain in one of the following ways.
    • Including a domain name prefix, for example, MYDOMAIN\user1
    • Including the domain, for example, user1@mydomain.com
  • Users who are in a domain that is not a vCenter Single Sign-On identity source cannot log in to vCenter Server. If the domain that you add to vCenter Single Sign-On is part of a domain hierarchy, Active Directory determines whether users of other domains in the hierarchy are authenticated or not.


  1. Log in with the vSphere Client to the vCenter Server connected to the Platform Services Controller.
  2. Specify the user name and password for administrator@vsphere.local or another member of the vCenter Single Sign-On Administrators group.
    If you specified a different domain during installation, log in as administrator@ mydomain.
  3. Navigate to the Configuration UI.
    1. From the Home menu, select Administration.
    2. Under Single Sign On, click Configuration.
  4. Click Identity Sources, select an identity source, and click Set as Default.
    In the domain display, the default domain shows (default) in the Domain column.