Motivating students to learn computer networking concepts is often difficult because many students find the subject rather technical, dry, and boring. To overcome this problem, the author has prepared some practical laboratory exercises (practicals) and other materials. They are designed around a network operating system and a multiuser, multitasking operating system and are suitable for classroom use in undergraduate computer networking courses. The effectiveness of these practicals has been evaluated both formally by students and informally in discussion within the teaching team. The implementation of the practicals was judged to be successful because of the positive student feedback and also because students scored better in the final exam. This paper describes the practicals, their overall effectiveness, and plans for further projects. The impact of practicals on student learning and comprehension is also discussed.