Hi,
I have set up SCCM 2012 r2 CU3 in our test environment. From my single primary site server I can push the SCCM client installation.
However i have downloaded MS updates, placed them in software update groups and deployed these groups. The clients realize they have updates to install but almost immediately go to the status of FAILED. Before my updates were showing "DOWNLOADING 0%" (and would sit at this 0% for hours, never increasing) and at the suggestion of others I changed my boundary group from a IP Subnet to an IP RANGE. Since that change they immediately fail.
The SCCM Site server sits on the same subnet as my test clients with no ACLs in place so no ports or traffic being blocked. If there is a particular log file that would help in resolving this let me know please.
I do have certs set up with my server and I do have the domain gpo setting to "specify intranet microsoft update service location" set to "https://SCCM01.local.lcl:8531"