One of the new features for the Hyper-V Virtual Switch in Windows Server® 2012 R2 is extended port Access Control Lists (ACLs). You can configure extended ACLs on the Hyper-V Virtual Switch to allow and block network traffic to and from the virtual machines (VMs) that are connected to the switch via virtual network adapters.

You can use the new topic Create Security Policies with Extended ACLs for Windows Server 2012 R2 at http://aka.ms/Wfpf5o to learn how to use new protocol-based and stateful rules.