Step 2: Verify That Prerequisites for RODC Deployment Are Complete

Applies To: Windows Server 2008

Before you can add a read-only domain controller (RODC) to any domain in the forest, the following prerequisites must be complete:

  • The forest functional level must be Windows Server 2003, Windows Server 2008, or Windows Server 2008 R2.

  • You must run the adprep /rodcprep command, and the changes must replicate throughout the forest. For more information about running adprep /rodcprep, see Running Adprep.exe (


When you run adprep /rodcprep, if you receive an error message that indicates that the command could not contact a replica for the partition DC=DomainDNSZones,DC=<domain> or for the partition DC=ForestDNSZones,DC=<domain>, see article 949257 in the Microsoft Knowledge base ( For more information about this error message, see Known Issues for Deploying RODCs (

  • At least one writable domain controller running Windows Server 2008 must be running in the same domain where you plan to install an RODC.

For more information, see Prerequisites for Deploying an RODC (