The Ethernet Port in the TBT3-UDV Dock Is Not Working When Connected to a Mac. In the ‘System Report’ Application (Apple Menu, About This Mac, System Report) and There Is No Ethernet Device Listed Under ‘Ethernet Cards’. How Do I Fix This?

Last Update: November 20th, 2020
Article ID: 736340

Typically this is caused by the system not correctly detecting the Ethernet device within the dock. In most cases, completely resetting the dock and ‘cold booting’ the system by following this procedure can help:

  1. Disconnect the dock’s Thunderbolt 3 cable from both the dock and the system, and disconnect the dock’s power cable so it turns off completely.
  2. Shutdown the Mac system completely (do NOT just restart).
  3. Power on the Mac system and login.
  4. Reconnect the power cable to the dock, and then reconnect the Thunderbolt 3 cable to both the dock and the system.
  5. Test the previously non-working Ethernet port.