As I just mentioned in a different thread, I'm staying at my sister's place for a few months and she has a non-Wi-Fi cable modem. The modem has both ethernet and USB ports. My rMBP doesn't have an ethernet port, so that option is out (unless I buy the Thunderbolt-to-Ethernet adapter). I tried connecting the modem directly to my rMBP via the USB port and it worked for about 2 minutes, but then the connection dropped. The same pattern repeated 3-4 times before I gave up. I know ethernet is the standard means of connecting a cable modem. Does this sound like a compatibility problem with the rMBP and/or modem, or could it be an unstable internet connection? It seems odd that it works when first plugged in, but then dies out within 1-2 minutes afterward. Thanks for all feedback.