MP 1,1-5,1 Phantom Ethernet "Adaptor" in Network System Pref Pane

[astonius86]

Several weeks ago I noticed a new listing in my Network preference pane for an "Ethernet Adaptor (en4)" (yes, it's misspelled). It has a self-assigned IP address and a MAC address of 02:00:00:00:01:01. I thought this might have been caused by OpenCore or a third-party kext, but even if I boot to macOS without OpenCore enabled I still see it. I can remove it, but it reappears after every restart. I'm running 10.15.5 on a 5,1. I have not made any hardware changes whatsoever and have attempted removing all peripherals. Any ideas what this could be and how to resolve it?

 

[gadgetboyj]

Do you (or did you) have the Logitech Harmony Remote configuration software installed? I have the exact same device with the exact same incorrect spelling, MAC address, and behavior, and I've narrowed it down to the driver that the Logitech Harmony software uses to communicate with the remotes.

You can verify this by observing first that the adapter shows connected with a Self-Assigned IP like in your photo:

Then go ahead and run sudo kextunload /Library/Extensions/logitech.kext in Terminal to shut down the driver. Observe now (hopefully) that the adapter now changes to 'Not Connected':

Now that you've confirmed, you can reload the driver by running sudo kextload /Library/Extensions/logitech.kext

I've left mine alone at this point because I do use the software to make changes to my Harmony Remotes, but if you no longer need the software, you can look into uninstalling it. Hope this helps someone!

 

[astonius86]

I completely forgot to update, but yes, you are correct! Logitech Harmony Remote software was the culprit. I no longer use that app, so once I fully removed it the “adaptor” was gone and has not returned. Thank you for confirming!