The Replication Diagnostics Tool (Repadmin.exe) is command line tool used to check replication between domain controllers. Repadmin.exe produces information that may be used to view information about a possible problem with replication in the forest. Repadmin.exe indicates when a problem change has been made to Active Directory. It can be as specific to report on metadata for specific objects and attributes. Repadmin.exe can even be used to create a replication topology or force replication between domain controllers.