After finally tracking down the power adapter for my switch, I wired units A and B together. Both have their white lights on, but I’m not sure that B is connecting via Ethernet. I connected an AppleTV 3 to the second port of B an restarted A. Now the AppleTV is connected to the network. It wasn’t on WiFi, so it’s definitely using Ethernet. When I check at covr.local, it shows that the AppleTV is connected on 5G. Not sure if that means B is connected only wirelessly. Or if that’s its way of showing it’s connected to B. But it is connected.