NIC teaming, bonding, load balancing, A+B networking, or whatever you want to call it, is a core concept in highly available server computing. In Windows, we’ve been able to create a virtual NIC that we configured TCP in by using 3rd party drivers from the likes of HP or Intel.
The virtual network is no different. ESX can do this by using two host physical NIC’s to connect a virtual switch. A VM has one virtual NIC that connects to this virtual switch and has the benefit of A+B networking. The Hyper-V virtual switch can only use one NIC. Hyper-V relies on drivers in the parent partition. You’d think "OK, lets team two physical NIC’s in the parent partition and use the resulting virtual NIC to connect the virtual switch". Right now, that’s not possible. HP says:
"IMPORTANT
Windows Server 2008 Hyper-V RC1 does not support the Network Configuration Utility (NIC Teaming). Deselect this component before installing the PSP components".
This is not good, not good at all. We cannot do A+B networking in Hyper-V until this changes. I’m told that MS is relying on partners, e.g. HP and Intel, to resolve this like they have done for Windows up to now. I’m really hoping that they do.
EDIT:
I got a respnse from Microsoft when I sent in some feedback on this issue. Officialy, MS does not support any kind of NIC teaming on Windows. Currently, this is no different with Hyper-V. They are relying 100% on partners such as the likes of HP, Broadcom and Intel to provide updated versions of their teaming drivers for Hyper-V. There is an opening in the parent paritition to allow partners to accomplish NIC teaming and present one virtual (teamed) NIC to a virtual switch in Hyper-V.