Product Reviews

A Few of My Favorite Things: RepAdmin

Compaq knows a thing or two about troubleshooting large networks. Here are some of the utilities and programs it uses most and likes best for Windows 2000.

While it’s not the most famous tool for AD administration in Win2K, the command-line utility RepAdmin, available in the Support Tools folder on the Win2K CD-ROM, offers valuable troubleshooting features. This tool provides a powerful interface into the inner-workings of AD replication and aids in troubleshooting AD replication problems on DCs.

Run Repadmin against each DC to determine if all DCs have the same replicated values. If a specific DC doesn’t have the same value and the change was made some time ago, you can begin investigating why the computer hasn’t yet received the change. Type repadmin at the command prompt to view supported commands and arguments.

Tip: The Knowledge Consistency Checker (KCC) must have run successfully for AD’s replication topology to be current. Type:


at the command prompt to determine the status of the KCC on a particular DC.

Replication topology has inbound and outbound connections from each DC to other DCs in a domain and, possibly, other domains in the same AD forest. The figure shows two DCs in a single domain, with no other domains in the forest.

Repadmin lists inbound and outbound replication partners. (Click image to view larger version.)

Since sites in AD affect the replication topology, the first output line shows the DC member’s site. The inbound and outbound neighbors show what the KCC has created. Information in the neighbors also shows sites, the name of the neighbor DC, and the transport mechanism (RPC or SMTP) used. There will be a minimum of three sets of neighbors per DC representing the schema context, configuration context and domain context partitions in AD. If there are additional domain context partitions, the DC is a Global Catalog server. You can display more detailed connection information with:


You may need to force replication on a DC. Replication is always a “pull” action. First, determine the name of the target server that needs to be synchronized. Then, at a command prompt, use Repadmin.exe to determine the target server’s direct replication partners:

repadmin /showreps

Under the Inbound Neighbors section of the output, the direct replication partners for each directory partition are identified along with the status of the last replication.

Find the directory partition that needs synchronization and locate the source server with which the target will be synchronized, then use Repadmin.exe to initiate replication by typing the following:

repadmin/sync directory_partition < source_server="">_objectGuid

If successful, Repadmin.exe displays the following message:

ReplicaSync() from source: objectGuid, to dest: localdc is successful.

As an option, you can use the following switches on the command line:

  • /force: Overrides the normal replication schedule.
  • /async: Starts the replication event. Repadmin.exe doesn’t wait for the replication event to finish.
  • /full: Forces a full replication of all objects from the destination DSA.

While most AD management tools are GUI-based, the simple and powerful command-line tool RepAdmin.exe provides many options that contribute to the successful management of AD in Win2K.

About the Author

Jim Hautala, MCSE, is a technology consultant, Windows and Messaging Practice, for Compaq in New England.


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