I just installed the Hyper-V role on my Windows Server 2012. It comes with something called a "Hyper-V extensible virtual switch". I assigned it to the only network card in my server. By doing so, the network card became useless/disabled/inactive/.. because the virtual switch disabled all features (IPv4, IPv6, Client for Microsoft Networks, …) on the network adapter.
Can the extensible virtual switch be used in a single NIC configuration? If so, how do I configure the host network after enabling the virtual switch?
Best Answer
In Windows Server 2008 R2 Hyper-V when using a single NIC and creating a Virtual Switch on that NIC, Hyper-V will create a virtual NIC that all of the networking components bind to and the physical NIC gets bound with the Microsoft Virtual Network Switch Protocol (which is the virtual switch driver). That shouldn't stop you from having normal network connectivity through the physical NIC.
In your case, the Hyper-V host and the Hyper-V guests will share the physical NIC. Make sure to check the check box on the Microsoft Virtual Switch that reads "Allow management operating system to share this network adapter".
That being said, at the very least you should have 2 network cards in the server: 1 dedicated for the host server and a second dedicated for the VM's.
I'm assuming all of the above is applicable in W2K12 and Hyper-V 2K12, or that it's very nearly applicable.
http://technet.microsoft.com/en-us/library/cc816585(v=ws.10).aspx