This revolutionary text and its accompanying CD replace a whole lab full of computer equipment. They give computer science students realistic hands-on experience working with network protocols, without requiring all the routers, switches, hubs, and PCs of an actual network. Using the latest version of the open source program Ethereal, the reader opens packet trace files from the CD and follows the text to perform the exercises, gaining a thorough understanding of the material in the best way possible?by seeing it in action. This approach also benefits the instructor, who is spared the time-consuming tasks of maintaining a laboratory and taking traces. It can even relieve the anxiety system administrators have about students collecting traces on campus networks!