This guide provides basic instruction on setting up autonomous or replica downstream WSUS servers. Downstream WSUS servers reduce overall off-campus bandwidth as updates are downloaded from Microsoft to the WSUS service once, and then distributed to campus downstream servers.
A replica downstream server uses another WSUS server as its master repository; any updates that the master server has downloaded will be available to the downstream server. The replica server:
Mirrors update approvals, settings, computers, and groups from its parent; updates can only be approved on the upstream (master) server.
Makes client status reports available to the master server, but does not upload them.
Must be in the same Active Directory forest as the master to allow for full reporting.
An autonomous downstream server, like a replica server, also uses another WSUS server as its master repository, but allows for individual approvals for updates different from those of the master. The autonomous server:
Allows flexibility in creating computer groups.
Does not have to be in the same Active Directory forest as the master.