If you're having issues with Thunderbolt networking, or if you were directed to this page when you connected a Mac to another host, check the following:
- Verify that your system supports Thunderbolt 3 over USB-C. Check with your system's manufacturer if you think the message was shown in error.
- Be sure to connect your Mac directly to the Thunderbolt 3 computer and not through a USB-C hub. USB-C hubs don't support Thunderbolt 3 connections between their ports.
- Make sure that the USB-C cable that you're using supports Thunderbolt 3. Not all USB-C cables support the requirements of Thunderbolt 3. For example, a USB-C charge cable doesn't support a Thunderbolt 3 connection.
- If you're connecting a Thunderbolt 3 Mac to a Thunderbolt 2 Mac, use an Apple Thunderbolt 3 (USB-C) to Thunderbolt 2 adapter and a Thunderbolt 2 cable.