Port Configuration

Linux Kernel Upstream Release Notes v6.5

Auto Sensing enables the NIC to automatically sense the link type (InfiniBand or Ethernet) based on the cable connected to the port and load the appropriate driver stack (InfiniBand or Ethernet).

Auto Sensing is performed only when rebooting the machine or after disabling/enabling the adapter cards from the Device Manager. Hence, if you replace cables during the runtime, the NIC will not perform Auto Sensing.

For further information on how to configure it, please refer to the “Port Protocol Configuration” section below.

  1. Display the Device Manager and expand “System devices”.


  2. Right-click on the Mellanox ConnectX Ethernet network adapter and left-click Properties. Select the Port Protocol tab from the Properties window.


    The “Port Protocol” tab is displayed only if the NIC is a VPI (IB and ETH).

    The figure below is an example of the displayed Port Protocol window for a dual port VPI adapter card.


  3. In this step, you can perform the following functions:

    • Choose HW Defaults option. In this case, the drivers behavior is as follow:

      • If HW Default option is chosen, the driver will use the Auto Sense option by default

      • If the Auto Sense option fails, the port protocols will be determined according to the NIC’s hardware default values

    • Choose the desired port protocol for the available port(s).
      If you choose IB or ETH, both ends of the connection must be of the same type (IB or ETH).


      Configuring Port 1 as Ethernet with RoCE disabled and Port 2 as IB, is not supported by the adapter card. If this configuration is created occasionally by auto sensing, the driver will fail to startup. If this configuration is intentionally defined as explained in Step 2 above, the driver will set RoCE mode to v1.5 to create a legal configuration. In all cases, it will send messages to System Event Log to notify the user about these actions.

  • Enable Auto Sensing by checking the AUTO check box.
    If the NIC does not support Auto Sensing, the AUTO option will be grayed out.


    If you choose AUTO, the current setting will indicate the actual port settings: IB or ETH.

    For firmware 2.32.5000 and above, there is an option to set port personality using mlxconfig tool. For further details, please refer to MFT User Manual.

© Copyright 2023, NVIDIA. Last updated on May 23, 2023.