SQL Native client Pre-req for running SCCM 2012 R2 SP1 testdbupgrade

When you want to test the service pack on a separate sql box with setup.exe /testdbupgrade CM_ABC you may run into an issue because you need the SQL Native client. The version you need regardless of what sql version you are running is from the SQL 2012 feature pack -

http://go.microsoft.com/fwlink/?LinkID=239648&clcid=0x409