Symptom

Certain USB based docking solutions now support a new “MAC address pass-through” feature. This feature allows the MAC address of the native Ethernet network device on the system to be used for imaging, systems management, etc.

Feature set:

• Docking device has its own network device with unique MAC.
• Feature provides a single system MAC for PXE boot, etc.
• Similar to the existing docking device with a RJ45 port.

Applicable Brands

ThinkPad

Applicable Systems

• X1 Carbon (5th Generation) (20HR, 20HQ)
• T470
• T470s
• T470p
• P51
• P71

System Is Configured With

KabyLake based ThinkPad notebook systems which support the following USB based Docks:

• ThinkPad USB-C Dock (40A9)
• ThinkPad Thunderbolt 3 Dock (40AC)
• Lenovo USB-C Travel Hub (4X90M60793, 4X90M60789, 03X7417)
• Lenovo USB-C to Ethernet Adapter (4X90L66917, 03X7205)

Limitations

The following docks are not supported:

• ThinkPad USB 3.0 Basic Dock (40AA)
• ThinkPad USB 3.0 Pro Dock (40A7)
• ThinkPad USB 3.0 Ultra Dock (40A8)

No update will be available to enable the “MAC address pass-through” feature for these docks.

Solution

To use the “MAC address pass-through” feature, the setting must be enabled in the BIOS. The setting is located in BIOS -> Config -> Network.

Change the setting to Enabled, then exit the BIOS while saving changes to the BIOS setting.

Related Articles

• Popular Topics: Docks, Docking
• Popular Topics: BIOS, UEFI