I have a brand new installation of Windows Server 2016 WSUS server (Fully patched until 18-Dec-2016). My network consists of about 1000 client-side operating systems and 300 server-side. The clients range from Windows 7 to Windows 10 version 1607. The servers are from Windows Server 2008 to Windows Server 2016. Every computer can connect to WSUS and pull the updates except for Windows Server 2016.
Each time I check for updates on a Windows Server 2016, I get this error: "We couldn't connect to the update service. We'll try again later, or you can check now. If it still doesn't work, make sure you're connected to the Internet."
Event Viewer: Windows Update failed to check for updates with error 0x80072EFD.
The strange thing is, WSUS server puts a green check mark for Windows Server 2016s, but I am sure there are some updates available for them.
I have installed all the Cumulative Updates (CUs) so far available for Windows Server 2016 on one of my 2016 installations manually, to see if that would solve the problem, but it didn’t. Any Idea?