This paper describes a novel approach to teaching computer networking through packet traces of actual network traffic. The paper describes a set of exercises that use packet traces to clearly illustrate the activity that takes place on the network under a variety of situations from traces of common network applications like e-mail and web browsing, to traces that illustrate backbone network activity like dynamic routing protocols, to traces of abnormal conditions like computer viruses or worms in action. Students can view each trace using freely available software that runs under both Windows and Linux. This method gives students the hands-on, practical learning style they find most interesting while eliminating the need to make specialized networking equipment available for laboratory exercises. The paper discusses the results of applying this method to a diverse set of courses including semester-long undergraduate courses in information technology and computer science, graduate cour...