What is MAC Address Pass-through

Applies to:

• Latitude
• Mobile Precision Workstation
• XPS

Some network software applications (Microsoft System Center Configuration Manager (SCCM) and various systems management applications) look for a system-unique Media Access Control (MAC) Address to allow a system access to a network or to allow a software installation to be sent from a network server.

Dell is solving a problem in the industry of USB-based Ethernet controllers. Dell has implemented a feature called MAC Address Override or MAC Address Pass Through that uses a system-unique MAC address entered in the system Basic Input/Output System (BIOS) which is then used to override the dock or dongle MAC address every time it’s connected to the network. This way the network sees the system-unique MAC address. Dell systems using Dell Type-C USB network dongles and docks will now have a constant MAC Address no matter which USB Type-C adapter is connected to the system.

Dell Type-C USB network adapters including the Dell Adapter – USB-C to Ethernet (RJ45) dongle, Dell DA200 Type-C Dock, The Dell Dock (WD15) and the Dell Thunderbolt Dock (TB16) all have their own MAC address built into their chipsets. When dock/adapter is connected to a Dell system that supports MAC Pass-through, and the network driver is loaded on the system, the adapter specific MAC address will be overridden by the system specific MAC address from the BIOS. This way the network consistently sees and uses the system specific MAC address.

Things to remember:

• This MAC Address Override feature is enabled using the BIOS and Network driver that resides in the operating system (Windows, Linux etc.).
• MAC Address Override does function before booting to the operating system and in the Preboot eXecution Environment (PXE) boot process.
• The system specific BIOS MAC address is listed in the BIOS so customers can view the MAC address without being in Windows.
• The MAC Address printed on the Dell dock label is not the MAC Address from the system BIOS.
• If the adapter/dongle is used on a Non-Dell system MAC Address Override is not available and the device will use the MAC address of the adapter/dongle only.

Recommended Articles

Here are some recommended articles related to this topic that might be of interest to you.

• MAC address pass through enabled on the Latitude 7400, but IPV4 options are not available in pre-boot menu
• Latitude 5300 2-in-1 and 5400 Chromebook: WD19/WD19S Dock MAC does not change after setting the MAC passthrough policy
• Dell USB-C Hub Monitors: MAC Address Pass-Through Not Available with Non-Dell Systems
• MAC Address pass-through limitations for docked portable systems