Chapter 5. OSPF Network Design

Now that you are familiar with the basics of topology and addressing design from the first four chapters in the book, it's time to implement some routing protocols on the network (illustrated in Figure 4-10) to gain a little more practical understanding of the problems and tradeoffs you will be working with. This part of the book begins with Open Shortest Path First (OSPF) because this is a popular protocol. See Appendix A, "OSPF Fundamentals," for a short description of how OSPF works.

This chapter begins by considering how to divide the network up into areas because this decision affects many other design decisions. In this planning, you'll learn where to summarize and deal with some issues common to dial backup—ways of handling the dial-in clients, the problems dial-in links cause, and how to deal with the external connections to the network. Finally, you'll learn about which areas can become stub areas of various types.