You have to install the correct driver (see other reviews), then everything is easily and "simply" works, even when off / plugging on the fly. I have this part of the USB hub of the external monitor (Dell U2415), who is also USB3 and does so in theory Gigabit Ethernet loose with - can my older MacBook Pro has only USB2, so come for USB data not in the original speed, but it the adapter anything. A colleague with a new Macbook Air swears on the adapter because it does not consume so its single Thunderbolt port for Ethernet, but also can connect a monitor via Thunderbolt :)