Running WSUS 3.0 in Replica Mode

Applies To: Windows Server 2003 with SP2, Windows Server Update Services

A WSUS server running in replica mode inherits the update approvals and computer groups created on its parent WSUS administration server. You will typically have a single parent server with one or more downstream replica WSUS servers. You approve updates and create computer groups on the parent server, which the replica servers will then mirror.

You may now designate any WSUS server as a downstream replica at any time. In the WSUS administration console, select Options, then Update Source and Proxy Server, and on the Update Source tab, select the Synchronize from another Windows Server Update Services server check box, and then the This server is a replica of the upstream server check box.

You will be able to perform only limited administration capabilities on a WSUS replica server, which will primarily consist of:

  • Adding and removing computers from computer groups

    A replica server inherits the computer groups that were created on the administration server. You must assign the replica server's client computers to the computer groups.

  • Viewing available updates

  • Monitoring update, synchronization, and computer status, and monitoring WSUS settings on the server

All standard WSUS reports are available on replica mode servers.

For more information about setting up and running in replica mode, see Deploying Microsoft Windows Server Update Services (

Replica server synchronization

If you are setting up many replica servers to connect to a single upstream WSUS server, you should not schedule synchronization to run at the same time on each replica server. This practice will avoid sudden surges in bandwidth utilization.

If a replica server tries and fails to synchronize with the upstream server, it will retry the synchronization twice at approximately fifteen-minute intervals. If both retries fail, the replica server will run synchronization at the next scheduled time.