KB - Verify the domain and forest functional level

Affects product

  • Active Directory / Windows Server 2012

Question or problem

Verify that the domain and forest functional level in Active Directory is Windows Server 2012 or higher.

Procedure-related prerequisites

  • You need to be logged in as a domain administrator on a domain controller.

Instruction

  • Test execution and verification:
  • 1.
    Go to: Administrative Tools >> Active Directory Users and Computers.
  • 2.
    In the left pane, right-click the root node for the domain. Then click Properties.
  • 3.
    In the left span, select the root node and click on Properties in the context menu.
  • The domain functional level and the forest functional level is Windows Server 2012 or higher.
  • In case of failure:
  • Raise the domain functional level.
  • Raise the forest functional level.
  • Solution - Raise the domain functional level
  • 1.
    Go to: Administrative Tools >> Active Directory Users and Computers.
  • 2.
    In the left pane, right-click the root node for the domain. Then click Raise domain functional level in the Action menu.
  • 3.
    Select Windows 2012 or higher from the Select an available domain functional level dropdown box.
  • 4.
    Click OK.
  • Solution - Raise forest functional level
  • 1.
    Go to: Administrative Tools >> Active Directory Domains and Trusts.
  • 2.
    In the left pane, right-click the Active Directory Domains and Trusts node (top element in the tree). Then click Raise Forest Functional Level... in the Action menu.
  • 3.
    Select Windows 2012 or higher from the Select an available domain functional level dropdown box.
  • 4.
    Click OK.

HIGH – Kerberos authentication fails

  • Raising the functional level cannot be undone.
  • Check first if all Windows clients support the higher functional level.