Book excerpt: For courses in Advanced Networking, or any course specializing in network technologies or LAN/WAN technologies. The most comprehensive network text ever written. Drawing on the author's extensive professional and educational experience, this text focuses on network design and the proper way to design an internetwork. Students will gain a solid background on networking protocols, architecture design, and designing specific types of networks along with legacy protocols such as AppleTalk, DNA, and SNA. It is also ideal for students studying to pass certified exams such as the CCDA, CCNA, and the Microsoft Networking Essentials Exam.