One of the new features in Hyper-V in Windows Server 2012 R2 is the concept of a protected network:
In Windows Server 2012 R2 any network adapter that is added to a virtual machine is automatically configured as a protected network adapter. This means nothing if you are not using Hyper-V clustering, but if you are using Hyper-V clustering it has an important effect.
Basically, we will monitor this network connection for any link failures.
If we detect that the virtual switch that is used for this virtual network adapter no longer has a functioning network connection – we will move the virtual machine to another node in the cluster. Before we do this though, we check to make sure that the destination computer does have a functioning network connection on the corresponding virtual switch (this is important to avoid mass virtual machine migrations in the event of a switch failure).
If you are using network teaming in the host environment, you are unlikely to suffer complete link failure – but this functionality gives you an extra level of protection for network connectivity.