WSUS downstream ==> upstream sync issue

Question

Hi everyone, We are experiencing issues with our WSUS servers. Our setup is as follows: Main server running MS Server 2022 synchronizing with Microsoft (that server is working fine). Downstream server running MS Server 2019 (in a different site) synchronizing with the main WSUS server - that server is experiencing sync issues, error message:

IOException: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host. ---> System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host at System.Net.ConnectStream.Read(Byte[] buffer, Int32 offset, Int32 size) at Microsoft.UpdateServices.ServerSync.ServerSyncCompressionProxy.GetWebResponse(WebRequest webRequest) at System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(String methodName, Object[] parameters) at Microsoft.UpdateServices.ServerSyncWebServices.ServerSync.ServerSyncProxy.GetRevisionIdList(Cookie cookie, ServerSyncFilter filter) at Microsoft.UpdateServices.ServerSync.CatalogSyncAgentCore.WebserviceGetRevisionIdList(ServerSyncFilter filter, Boolean isConfigData) at Microsoft.UpdateServices.ServerSync.CatalogSyncAgentCore.ExecuteSyncProtocol(Boolean allowRedirect) We have confirmed that all the necessary ports are open on our Firewall. Any suggestions how to resolve this are greatly appreciated Thanks

Answer 1

Re-setup the SSL (assuming SSL) on BOTH systems.

https://www.ajtek.ca/wsus/how-to-setup-manage-and-maintain-wsus-part-7-ssl-setup-for-wsus-and-why-you-should-care/

At a minimum, run the steps Require SSL for the following virtual roots only and Switch WSUS to SSL and then try syncing again.