I've managed to kill network access to my Hyper-V server as a result of enabling the "VLAN ID" option as well as the "Enable virtual LAN identification for management operating system" option (screenshot below from a working server):
My machine is a Server Core installation of Windows Server 2012 R2. Unfortunately, it seems I have not installed the Hyper-V cmdlets, so I'm not able to clear the "VLAN ID" setting from the virtual switch using PowerShell.
To further complicate things, I'm not able to add any Windows features (to install the Hyper-V cmdlets, or to install the server GUI) by using the "Add-WindowsFeature" cmdlet because I keep getting this error "The source files could not be downloaded":
I followed the steps here to mount the Windows Server 2012 R2 ISO file to a temporary directory, then use that as the source for my Add-WindowsFeature cmdlet, but I still get the same error ("The source files could not be downloaded").
So I can't load the GUI, I can't connect to it over the network, and I can't modify the virtual switch using PowerShell. Any tips would be greatly appreciated!
Shaun