I've used a few usb ethernet adapters over the years, and the most reliable and performant one in my experience is the StarTech USB31000S which is based on the

I've used a few usb ethernet adapters over the years, and the most reliable and performant one in my experience is the StarTech USB31000S which is based on the ASIX AX88179. It's been around for a few years so the driver for it is included in all recent linux distros, and you can download surprisingly up-to-date and maintained drivers for OS X and windows from the chip manufacturer's website: http://www.asix.com.tw/products.php?op=pItemdetail&PItemID=131;71;112&PLine=71 http://www.asix.com.tw/products.php?op=pItemdetail&PItemID=1... I use it mostly with OS X. I've actually bought about 5 of them, because some coworkers had problems that turned out to be caused by flaky usb ethernet adapters, and it was well worth my debugging time to get them better (but still cheap!) hardware.