Checklist: Deploying Virtual Machine Chimney

Applies To: Windows Server 2008 R2

To deploy Virtual Machine Chimney, perform the tasks in the order listed. Virtual Machine Chimney is only available on computers running Windows Server® 2008 R2 with the Hyper-V server role installed.


Some applications and features may have limited interoperability with TCP Chimney Offload. For more information, see TCP Chimney Offload and Virtual Machine Chimney Compatibility with Other Applications and Features.

  Task Reference

Ensure that the physical network adapter of the management operating system supports TCP Chimney Offload, and then enable TCP Chimney Offload for the adapter.

Enabling TCP Chimney Offload for a Physical Network Adapter

Modify registry settings on the management operating system to enable Virtual Machine Chimney.

Enabling Virtual Machine Chimney on the Management Operating System

Configure the virtual network adapter of the virtual machine to use the physical network adapter that has TCP Chimney Offload enabled.

If you are using System Center Virtual Machine Manager (VMM) 2008 or 2008 R2, ensure that the Enable Virtual Network Optimizations check box is selected on the Hardware Configuration tab of the Virtual Machine Properties. If you are not using VMM, and you use the Windows Management Interface (WMI), ensure that the ChimneyOffloadWeight is left at its default value or configured to a non-zero value.

See Configuring Virtual Networks in VMM on Microsoft TechNet and

the entry for ChimneyOffloadWeight in the Msvm_SwitchPort Class reference on MSDN.

Use Netsh commands to set TCP Chimney Offload to operate in automatic or enabled mode in the virtual machine operating system.

Using Netsh Commands to Enable or Disable TCP Chimney Offload