Moy’s book is the only volume dedicated solely to explaining open shortest path first (OSPF) protocol that exists in the market. People may very well prefer this book to the plain text 244-page Internet Engineering Task Force’s Request for Comments (IETF RFC). As author of OSPF versions 1 and 2, Moy was the most qualified person to write this much-needed book. OSPF is a complex routing protocol, and books that partially deal with the subject often do not do so thoroughly enough. The audience for this book is anyone interested in learning about the protocol, such as network engineers, designers, researchers, and network operations staff.

The book starts with an overview of Internet routing protocols and routing technologies. Readers who are familiar with the topic can safely ignore this section. The core of the book is contained in chapters 3 through 7, which describe the OSPF protocol. Chapter 3 is an interesting read because it highlights how OSPF evolved into its current stage from its historical beginnings. The requirements of the routing protocol, how the decisions were made in IETF, version 1, field trials, and the success and problems encountered are described in this chapter. The problems faced in the early days of OSPF ultimately led to the now stable version 2 of the protocol. Chapter 4 establishes the foundations of OSPF, with an example network topology and various packet formats used by OSPF packet types. Chapter 5 delves into various types of networks including broadcast and non-broadcast multi access (NBMA), and leads to multipoint and how OSPF works in these networks. Concept of areas and hierarchical networks are explained in the next chapter. Various extensions of OSPF have sprung up, and they are explained in chapter 7. Though the core chapters describe the OSPF protocol, for the serious developer or a person who wants to troubleshoot a network through a sniffer, the OSPF version 2 RFC 2328 is still a must-read. The book provides a very conceptual and logical understanding of the OSPF, and lays the foundation for reading the RFC. Both are complementary, and one does not substitute for the other.

A chapter in the form of frequently asked questions (FAQ) is included, which is a welcome change (rather than addressing these in specific sections of each chapter). The book also covers multicast OSPF in great detail, and deals with configuration and management, frequently ignored subject matter in many protocol books, but a very crucial element in the big picture. The book has a section on the OSPF management information base (MIB), and provides an overview of all the tables contained in the MIB. Small sample configurations are also included. Moy devotes a section to debugging the implementations and provides various clues to the reader who may be troubleshooting OSPF in a production or test network. This will be really useful to the network operations staff at network operations centers (NOCs) that will be troubleshooting live OSPF networks. Even though OSPF implementations could be relatively bug-free, operator errors could really cripple the networks, so good troubleshooting/debugging skills are very important. The book ends with a comparison of various unicast and multicast routing protocols, and includes an extensive bibliography of routing protocol literature.

Although I would have liked more details to be included in the core OSPF chapters, the explanation is sufficient to spark a reader’s interest in pursing the topic further. Moy has also written a companion book (sort of a second volume), describing his own implementation of OSPF. It describes a C++ implementation, and is useful for developers and engineers interested in implementing OSPF, which is the subject of the author’s a Web site http://www.ospf.org.