Using Windows 10 to manage Hyper-V on Windows Server 2008 R2
Solution 1:
We have submitted a ticket into Microsoft. After 4 days of their tech support, we closed the ticket. Final answer, NO Hyper-V Manager on Windows 10 will not communicate to Server 2008 r2.
Solution 2:
Supported combinations of Hyper-V and Hyper-V manager are documented here : https://docs.microsoft.com/en-us/windows-server/virtualization/hyper-v/manage/remotely-manage-hyper-v-hosts
Basically, starting with Windows Server 2012 / Windows 8.1 and up to Windows Server 2016 / Windows 10, Hyper-V manager can manage same and older versions of Hyper-V. For older versions, only the the matching server and client versions of Windows are compatible.