Mellanox CX-3 network adapter configurations lost after an in-place upgrade in Windows Server

Applies to: Windows Server 2012 R2Windows Server 2012


Consider the following scenario:

  • On a Windows Server 2012 R2 or Windows Server 2012-based computer, a Mellanox CX-3 network adapter is installed.
  • The driver for the network adapter is version 4.x.x or an earlier version.
  • You do one of the following in-place upgrades on the computer:
    • Windows Server 2012 R2 to Windows Server 2016
    • Windows Server 2012 R2 to Windows Server 2019
    • Windows Server 2012 to Windows Server 2016

In this scenario, the configuration on the Mellanox ConnectX-3 adapter isn't migrated. Instead, the configuration settings are reset to their default values after the in-place upgrade.

Additionally, other features that were configured on the adapter (such as Hyper-V Switches) are also not migrated.


The Plug-and-Play (PnP) hardware IDs on Mellanox CX-3 driver versions 4.x.x and version 5.x.x are incompatible. As a result, Windows reinstalls the adapter and uses a new PnP hardware ID.


To fix this issue, download and install the latest CX-3 drivers from Mellanox before you do the in-place upgrade. Make sure that the installed driver version is at least 5.x.x.