We have centerl Server and three primary servers. I was trying to deploy june month patches to clients. Clients under primary.contoso.com received windows updates with out any issue. But clients under primary2 and primary3 servers didn’t received updates.
try to telent from central server
telnet.primary1.contoso.com 80 ( I was able to telnet)
telnet.primary2.contoso.com 80 ( I am uanble to telnet)
telnet.primary3.contoso.com 80 ( I am uanble to telnet)
So the issue figure it out that ports were blocked from central server to child server. Port 445 and port 80 (or your custom ports) is used to communicate between a parent server with a wsus to a child server with wsus.
I had similar experiance in last month. That time clients under priamry1.contoso.com didn’t receive updates. I did some research and find out that Management Point was not working on that priamry server . Once i removed the MP role and add it back it start getting updates.
If you have issue like few of the clients not recieving updates you also need to check the below steps from your failed computer
gpedit.msc —> Computer configuration—>Administrative Templates—>Windows Components–>Windows Updates—>specify intranet microsoft update service location—> check the servername and port number. Try to telent from client to that server with port. If you are not able to connect means open that port from client to server