In Windows Server 2008, the DFS Replication service can be used for replication of the SYSVOL share between domain controllers operating in the Windows Server 2008 domain functional level. The DFS Replication service supports replication of the contents
Read More...
Read the complete post at http://blogs.technet.com/filecab/archive/2008/02/04/how-does-dfsr-function-on-read-only-domain-controllers.aspx