IBM Support

Windows 2008 and TCP Chimney - VMXNET vnics



The VMXNET virtual NIC adapters do not support the Windows® TCP Chimney option.


VMs on ESX(i) 4.x, 5.0, 5.1, 5.5

Resolving The Problem

Windows 2008 by default has the TCP chimney feature enabled. In some cases the vnic connectivity can be more stable by disabling this feature within an ESX/ESXi VM at version 4.x and higher. This occurs because the VMXNET virtual adapters do not support TCP chimney option.

Within the Windows VM run the CMD command:
netsh int tcp set global chimney=disabled

This is also covered in VMware® KB:

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Document Information

Modified date:
27 February 2020