Can Joeys communicate via Ethernet as opposed to cable

Not sure about with Ethernet, however one of my Joeys de-linked itself last night and they are hooked thru MoCA. So not sure what's up with that, hope it's not going to happen a lot. I had to go into the broadband menu (blue button - broadband - red button - MoCA) and hit "Reset Connection" on the Hopper for the Joey to link back.