I have just purchased a second rMBP and assumed that I could connect them to each other via thunderbolt for file sharing. The supplied 2m thunderbolt cable prompts nothing in the network settings but works fine if I use two thunderbolt > ethernet adaptors. Thunderbolt over ethernet works fine and is fast enough, but I'd rather use one cable over three! It's not a big issue as I'm only doing it to restore boot images etc... Is it supposed to work? Any tips?