Let's move the focus a bit away from the hypervisor to discuss the security aspects of the new extensible virtual switch and virtual network of VMs. Windows Server 2012 and Windows Server 2012 R2 saw major changes to the Hyper-V design. One notable difference was the virtual switch that Microsoft offered in the current releases. It is completely different from the standard virtual switch offered with earlier platforms and referred to as the Extensible Virtual Switch (EVS).

The EVS, apart from performing its layer 2 responsibilities, can be programmatically enhanced (using published Windows APIs) by adding extensions for monitoring, modifying, and forwarding traffic to the extensible ports. Unlike VMware where the vSwitch is replaced, Hyper-V allows third party developers to build extensions, which are MS certified filter drivers based on the Network Driver Interface Specification (NDIS) and Windows Filtering Platform (WFP). There are three extensions that can...