USB ethernet adapter not working with 2012 Retina MBP I've got a 2012 Retina MBP running 10.11.3. In the past I've used a Linksys USB3GIGv1 ethernet adapter to connect to a wired network, however for the past week or so it hasn't worked.

When I plug the adapter into the USB port with System Preferences &gt; Network open, nothing gets updated; the interface doesn't show up in the list on the left side of the window, and if I turn Wi-Fi off, I lose my connection to the internet. The light on the adapter does flash at random, though, as it used to.

I tried disabling and re-enabling all the interfaces through ifconfig &lt;iface name&gt; off/on, but no luck there. I've also tried using an unbranded ethernet adapter which had previously worked, as well as switching out the cables for one with a known working connection, and even hooking the dongle up to a Thunderbolt display, but all to no avail.

The dongle does show up in System Information &gt; USB and the brand and model are correctly identified on the USB 3.0 bus.

Finally, I've tried manually installing the drivers from Linksys's website, but they only support OS X up to 10.9 (I had used this dongle post-10.11, and it stopped working almost randomly).

How can I get my MacBook to connect to the internet using an ethernet adapter considering all of that?
The old driver probably doesn't work with El Capitan. As indicated on the Linksys website Belkin is working on creating a Linksys driver package for the OS X 10.11.

Meanwhile you may try the RealTek beta driver here.