# Microsoft* Hyper-V* Overview

Microsoft* Hyper-V* makes it possible for one or more operating systems to run simultaneously on the same physical system as virtual machines. This allows you to consolidate several servers onto one system, even if they are running different operating systems. Intel® Network Adapters work with, and within, Microsoft Hyper-V virtual machines with their standard drivers and software.

See http://www.intel.com/technology/advanced_comm/virtualization.htm for more information on using Intel Network Adapters in virtualized environments.

# Using Intel® Network Adapters in a Hyper-V Environment

When a Hyper-V Virtual NIC (VNIC) interface is created in the parent partition, the VNIC takes on the MAC address of the underlying physical NIC. The same is true when a VNIC is created on a team or VLAN. Since the VNIC uses the MAC address of the underlying interface, any operation that changes the MAC address of the interface (for example, setting LAA on the interface, changing the primary adapter on a team, etc.), will cause the VNIC to lose connectivity. In order to prevent this loss of connectivity, Intel® PROSet will not allow you to change settings that change the MAC address.

## The Virtual Machine Switch

The virtual machine switch is part of the network I/O data path. It sits between the physical NIC and the virtual machine NICs and routes packets to the correct MAC address. Enabling Virtual Machine Queue (VMQ) offloading in Intel(R) ProSet will automatically enable VMQ in the virtual machine switch. For driver-only installations, you must manually enable VMQ in the virtual machine switch.

## Using ANS VLANs with Microsoft Hyper-V VLANs

If you create ANS VLANs in the parent partition, and you then create a Hyper-V Virtual NIC interface on an ANS VLAN, then the Virtual NIC interface *must* have the same VLAN ID as the ANS VLAN. Using a different VLAN ID or not setting a VLAN ID on the Virtual NIC interface will result in loss of communication on that interface.

## Using an ANS Team as a Virtual NIC

If you want to use a team or VLAN as a virtual NIC you must follow these steps:

| Note: This applies only to virtual NICs created on a team or VLAN. Virtual NICs created on a physical adapter do not require these steps.

1. Use Intel® PROSet to create the team or VLAN.
2. Open the Network Control Panel.
3. Open the team or VLAN.
4. On the General Tab, uncheck all of the protocol bindings and click OK.
5. Create the virtual NIC. (If you check the "Allow management operating system to share the network adapter." box you can do the following step in the parent partition.)
6. Open the Network Control Panel for the Virtual NIC.
7. On the General Tab, check the protocol bindings that you desire.

   | Note: This step is not required for the team. When the Virtual NIC is created, its protocols are correctly bound.

## Virtual Machine Queue Filter Offloading

Enabling VMQ Filter offloading increases receive and transmit performance, as the adapter hardware is able to perform these tasks faster than the operating system. Offloading also frees up CPU resources. Filtering is based on MAC and/or VLAN filters.

> ### Teaming Considerations

- If VMQ is not enabled for all adapters in a team, VMQ will be disabled for the team.
- If an adapter that does not support VMQ is added to a team, VMQ will be disabled for the team.
- Virtual NICs cannot be created on a team with Receive Load Balancing enabled. Receive Load Balancing is automatically disabled if you create a virtual NIC on a team.
- If a team is bound to a Hyper-V virtual NIC, you cannot change the Primary or Secondary adapter.

`Last modified on 9/08/09 8:57p Revision 11`