Steps to configure WSUS Replica Server

This article has steps on how to configure WSUS Replica Server

Pre-Requisite- make sure the required ports are open between Primary and replica WSUS server

Steps in WSUS Replica

Once the WSUS server setup is complete, please follow the instructions below to set up a WSUS replica:

1. Open the Windows Server Update Services from Server Manager -> Tools.
2. The first window will explain the requirements that must be met to proceed. Click "Next" to continue.
3. Leave the option as is or uncheck it, then click Next
4. Select the option "Synchronize from another Windows Server Update Services"
5.  Enter the FQDN of the Upstream Server
6.  Depending on your requirements, check "This is a replica of the Upstream." Click Next
7. Click on "Start Connecting."
8. Select the language for the Windows updates. If you only use Windows in English, choose English. Otherwise, select the appropriate languages based on your requirements. And click Next
9. Schedule the synchronization. Note that the synchronization will be between this WSUS server and the WSUS server you selected in the previous steps. 
10. Check the "Begin initial synchronization" option and click "Next" if you wish to start immediately after completing the configuration. 
11. Click on Finish button

Steps in Primary WSUS

1. After completing the configuration, log in to the WSUS Upstream Server.
2.  Expand the WSUS section and click on Downstream Servers.
3. Ensure that the Downstream Server is listed there.