Just purchased a new 5th generation Airport Extreme. Can I use my old 2nd generation as an extension without using wi-fi? I would like to place my old unit behind my tv. Hard wired from the new one to the old one via ethernet and then hard wire my Apple TV, blu ray player, etc to it. Right now they are wi-fi. Can I turn off wi-fi on the old unit? and only use it as a way to hard wire . I certainly do not want the old unit messing with the new one as far as wifi is concerned. Hope this makes sense on what I want to do.