Okay, so I am a CCNA and need to renew it. So I was just going to take the CCNA Wireless because I do have some experience in it. I bought the official Cisco Press book for the 640-721 and read it cover to cover a couple of times, and studied my highlighted portions many more times. However, when I went to take the test I was obvious that at least half the questions required more in depth knowledge than the book provided. Does anyone know if there is another, more detailed, book I can read. I refuse to go the route of brain dumbs. I want to actually learn what I don't know, but I feel like I know everything in the book that I read. Thanks for any help.