Internet Core Protocols: The Definitive Guide

Organization

This book deals with the basic building block protocols that provide the networking and transport services that all TCP/IP applications and services use. There are chapters on IP, UDP, TCP, and the common support protocols like ICMP, IGMP and ARP. The end of this book also contains appendixes on material that is indirectly related to how these protocols function.

Here’s a more detailed, chapter-by-chapter breakdown:

• Chapter 1, provides a history of TCP/IP, its design objectives, and an overview of the inter-relationships between the different protocols.

• Chapter 2, discusses the Internet Protocol in detail, including fundamentals of IP addresses, packet forwarding, the limited reliability services offered, fragmentation, and prioritization.

• Chapter 3, illustrates how IP devices are able to locate each other on a network, and the variations of ARP that are commonly used for different types of tasks.

• Chapter 4, describes how multicasting works on a network, and how devices register with multicast routers in order to participate in distributed multicast feeds.

• Chapter 5, discusses the error-reporting services used by IP, how the different ICMP messages are implemented, and also shows how the interactive services offered over ICMP can be used to diagnose your network.

• Chapter 6, explores the lightweight, error-prone transport protocol used by applications that don’t need TCP’s reliability service.

• Chapter 7, covers all the major aspects of this excruciatingly complex transport protocol, including the flow-control, reliability, network- and application-management services that are used by almost every Internet-based application today.

• Appendix A, discusses the process by which Internet developers write proposals that eventually become standards, and also describes the authoritative bodies that oversee the process.

• Appendix B, provides a detailed discussion on IP addresses and their formatting rules.

Each chapter is divided roughly into three sections: an introduction to the protocol, the details of the protocol’s syntax, and some real-time usage and troubleshooting notes. How you read this book will depend on who you are and what you’re trying to do.

Beginners

If you’re new to TCP/IP networks and want to learn more about the general concepts and architectural issues of the protocol suite (or of the Internet in general), you should read Chapter 1, followed by the introductory material in Chapter 2, and Chapter 7. By reading this material, you’ll get a sound understanding of how TCP/IP really works.

Working managers

If you’re responsible for managing a network and are looking for a thorough understanding of the core protocols, then you may want to read the introductory material provided at the beginning of Chapter 2, Chapter 7 and Chapter 5. In fact, you probably should do this as soon as possible, before you start having problems. You can then come back and read the reference material and troubleshooting tips whenever problems do crop up.

If you’re already having some kind of problem with a particular protocol or service, then you should probably start capturing packets, and study the detailed reference sections for the specific protocols that are giving you grief. Study the packet captures, and try to see where things start breaking down. Then look at the packets that are having problems, locate the appropriate parts in the reference section of the appropriate chapter, and see if you can figure out what the problem might be.

Ultimately, RFCs—another tool that no network manager should be without—define how your network should work. The RFCs are all available online, though if your network isn’t working, you might not be able to access them. With this book, a network analyzer, and the RFCs, you’ll have everything you need for a late-night troubleshooting session—except coffee.