For macOS 10.14 and above, locate the driver at /System/Library/Extensions/tn40xx.kext and for older systems, locate the driver at /Library/Extensions/tn40xx.kext.Name the new network device and click Create to add it to the list.Click on the little plus sign in the bottom left corner and select the new adapter (e.g. If you have followed all the instructions above to install the driver but your Thunderbolt Ethernet adapter does not show up automatically on the list of network devices, please add it manually.The driver should now load correctly and from this point forward, the network adapter will be recognized automatically.If necessary, disconnect and re-connect the network adapter and then click Allow to unblock the driver from ' Tehuti Networks Ltd' or ' Other World Computing Inc' and allow it to load. Set the security settings to allow apps downloaded from ' App Store and identified developers'. If the settings are currently locked, click on the lock first to make the following changes.Go to Preferences > Security & Privacy.You might also get a warning prompt at this time saying that the system extension by 'Tehuti Networks Ltd' or 'Other World Computing Inc' is blocked.

This could be caused by third-party software like Jamf Pro or by the secuirty settings of macOS. If it says No, the driver might be blocked due to security reasons.

If you are using macOS 10.13 or higher and you have followed the instructions above to install the driver but your Thunderbolt Ethernet adapter does not show up on the list of network devices, please check the system report on your Mac to see if the driver has been installed succesfully.

Important information for macOS High Sierra (macOS 10.13) and above

Go to Preferences > Network and your new Ethernet adapter should now be available.

Connect the network adapter to your computer.

Click Close to complete the installation.

Enter the username and password for your computer and click Install Software.

Click Continue and follow the installation wizard.Locate the downloaded file in the Finder, control-click and select Open.

Usb to ethernet mac driver