It is often difficult to motivate students to learn local area network (LAN) design because many students appear to find the subject rather dry, technical and boring. To overcome this problem the author has developed a software tool (named LAN-Designer) that gives students an interactive learning experience in LAN design concepts. The LAN-Designer is suitable for classroom use in introductory computer networking courses. This chapter describes LAN-Designer and its effectiveness in teaching and learning LAN design. The effectiveness of LAN-designer has been evaluated both formally by students and informally in discussion within the teaching team. The feedback from students indicates that the development and implementation of LAN-Designer were successful. It also discusses the impact of LAN-Designer on student learning and comprehension.