TCP/IP Illustrated I: The Protocols: 001 [Englisch] [Gebundene Ausgabe]

TCP/IP Illustrated, Volume 1: The Protocols is an excellent text that provides encyclopedic coverage of the TCP/IP protocol suite. What sets this book apart from others on this subject is the fact that the author supplements all of the discussion with data collected via diagnostic programs; thus, it is possible to "watch" the protocols in action in a real situation. Also, the diagnostic tools involved are publicly available; the reader has the opportunity to play along at home. This offers the reader an unparalleled opportunity to really get a feel for the behavior of the protocols in day-to-day operation. TCP/IP Illustrated, Volume 1: The Protocols features clear discussions and well-designed figures.

Volume two of this series, TCP/IP Illustrated, Volume 2: The Implementation, covers the implementation of TCP/IP. Volume three explores TCP for Transactions, HTTP, NNTP, and the Unix Domain Protocols.

For students writing applications that run over TCP/IP, or for those responsible for managing and maintaining a TCP/IP internet, this book's innovative approach helps readers at all levels to truly understand how TCP/IP really works. Rather than just describing the protocols from an abstract, standards-related point of view-describing what the standards say the protocol suite should do-TCP/IP Illustrated, Volume 1 actually shows the protocols in action. Stevens also recognizes that readers deal with multiple TCP/IP implementations on heterogeneous platforms. Therefore, the examples in this book show how current, popular TCP/IP implementations operate-SunOS 4.1.3, Solaris 2.2, System V Release 4, BSD/386, AIX 3.2.2, and 4.4 BSD-and they relate these real-world implementations to the RFC standards.

For students writing applications that run over TCP/IP, or for those responsible for managing and maintaining a TCP/IP internet, this book's innovative approach helps readers at all levels to truly understand how TCP/IP really works. Rather than just describing the protocols from an abstract, standards-related point of view-describing what the standards say the protocol suite should do-TCP/IP Illustrated, Volume 1 actually shows the protocols in action. Stevens also recognizes that readers deal with multiple TCP/IP implementations on heterogeneous platforms. Therefore, the examples in this book show how current, popular TCP/IP implementations operate-SunOS 4.1.3, Solaris 2.2, System V Release 4, BSD/386, AIX 3.2.2, and 4.4 BSD-and they relate these real-world implementations to the RFC standards.

TCP/IP Illustrated is a complete and detailed guide to the entire TCP/IP protocol suite-with an important difference from other books on the subject. Rather than just describing what the RFCs say the protocol suite should do, this unique book uses a popular diagnostic tool so you may actually watch the protocols in action.By forcing various conditions to occur-such as connection establishment, timeout and retransmission, and fragmentation-and then displaying the results, TCP/IP Illustrated gives you a much greater understanding of these concepts than words alone could provide. Whether you are new to TCP/IP or you have read other books on the subject, you will come away with an increased understanding of how and why TCP/IP works the way it does, as well as enhanced skill at developing applications that run over TCP/IP.

With this unique approach, TCP/IP Illustrated presents the structure and function of TCP/IP from the link layer up through the network, transport, and application layers. You will learn about the protocols that belong to each of these layers and how they operate under numerous implementations, including Sun OS 4.1.3, Solaris 2.2, System V Release 4, BSD/386TM, AIX 3.2.2, and 4.4BSD.In TCP/IP Illustrated you will find the most thorough coverage of TCP available - 8 entire chapters. You will also find coverage of the newest TCP/IP features, including multicasting, path MTU discovery, and long fat pipes.

"While all of Stevens' books are excellent, this new opus (TCP/IP Illustrated, Volume 1) is awesome. Although many books describe the TCP/IP protocols, the author provides a level of depth and real-world detail lacking from the competition."
- Unix Review

"This book (TCP/IP Illustrated, Volume 1) is a stone jewel...Written by W. Richard Stevens, this book probably provides the most comprehensive view of TCP/IP available today in print."
- Boardwatch

"The diagrams he uses are excellent and his writing style is clear and readable. Please read it (TCP/IP Illustrated, Volume 1) and keep it on your bookshelf."
- Sys Admin

"The word 'illustrated' distinguishes this book (TCP/IP Illustrated, Volume 1) from its many rivals. Stevens uses the Lawrence Berkeley Laboratories tcdump program to capture packets in promiscuous mode under a variety of OS and TCP/IP implementations. Studying tcdump output helps you understand how the various protocols work."
- Unix Review

We are deeply saddened to learn of the death of noted author W. Richard Stevens. His passing is obviously a tremendous loss for the technical community, but it is a personal one for us as well. Rich was both a gifted colleague and a valued friend who will be greatly missed. We extend our sympathies to his family. Obituary from the Arizona Daily Star: STEVENS, W. Richard, noted author of computer books died on September 1. He is best known for his "UNIX Network Programming" series (1990, 1998, 1999), "Advanced Programming in the UNIX Environment" (1992), and "TCP/IP Illustrated" series (1994, 1995, 1996). Richard was born in 1951 in Luanshya, Northern Rhodesia (now Zambia), where his father worked for the copper industry. The family moved to Salt Lake City, Hurley, New Mexico, Washington, DC and Phalaborwa, South Africa. Richard attended Fishburne Military School in Waynesboro, Virginia. He received a B.SC. in Aerospace Engineering from the University of Michigan in 1973, and an M.S. (1978) and Ph.D. (1982) in Systems Engineering from the University of Arizona. He moved to Tucson in 1975 and from then until 1982 he was employed at Kitt Peak National Observatory as a computer programmer. From 1982 until 1990 he was Vice President of Computing Services at Health Systems International in New Haven, CT, moving back to Tucson in 1990. Here he pursued his career as an author and consultant. He was also an avid pilot and a part-time flight instructor during the 1970's. He is survived by his loving wife of 20 years, Sally Hodges Stevens; three wonderful children, Bill, Ellen and David; sister, Claire Stevens of Las Vegas, NV; brother, Bob and wife Linda Stevens of Dallas, TX; nieces, Laura, Sarah, Collette, Christy; and nephew, Brad. He is predeceased by his parents, Royale J. Stevens (1915-1984); and Helen Patterson Stevens (1916-1997). Helen lived in Tucson from 1991-1997, and Royale lived here in the early 1930's attending Tucson High School while his father was treated for TB at the Desert Sanitorium (now TMC). The family asks that in lieu of flowers, donations be made in Richard's name to Habitat for Humanity, 2950 E. 22nd Street, Tucson, AZ 85713. A memorial service for Richard will be held at St. Phillip's in the Hills Episcopal Church on Tuesday, September 7th at 12:00 noon. Following the service there will be a reception in the Murphy Gallery of the Church. Please wear colorful clothing to the service; Richard loved colors. W. Richard Stevens was an acknowledged UNIX and networking expert and the highly-respected author of several books. He was also a sought-after instructor and consultant.

Introduction

This book describes the TCP/IP protocol suite, but from a different perspective than other texts on TCP/IP. Instead of just describing the protocols and what they do, we'll use a popular diagnostic tool to watch the protocols in action. Seeing how the protocols operate in varying circumstances provides a greater understanding of how they work and why certain design decisions were made. It also provides a look into the implementation of the protocols, without having to wade through thousands of lines of source code.

When networking protocols were being developed in the 1960s through the 1980s, expensive, dedicated hardware was required to see the packets going "across the wire." Extreme familiarity with the protocols was also required to comprehend the packets displayed by the hardware. Functionality of the hardware analyzers was limited to that built in by the hardware designers.

Today this has changed dramatically with the ability of the ubiquitous workstation to monitor a local area network Mogul 1990. Just attach a workstation to your network, run some publicly available software (described in Appendix A), and watch what goes by on the wire. While many people consider this a tool to be used for diagnosing network problems, it is also a powerful tool for understanding how the network protocols operate, which is the goal of this book.

This book is intended for anyone wishing to understand how the TCP/IP protocols operate: programmers writing network applications, system administrators responsible for maintaining computer systems and networks utilizing TCP/IP, and users who deal with TCP/IP applications on a daily basis.

Organization of the Book

We take a bottom-up approach to the TCP/IP protocol suite. After providing a basic introduction to TCP/IP in Chapter 1, we will start at the link layer in Chapter 2 and work our way up the protocol stack. This provides the required background for later chapters for readers who aren't familiar with TCP/IP or networking in general.

This book also uses a functional approach instead of following a strict bottom-to-top order. For example, Chapter 3 describes the IP layer and the IP header. But there are numerous fields in the IP header that are best described in the context of an application that uses or is affected by a particular field. Fragmentation, for example, is best understood in terms of UDP (Chapter 11), the protocol often affected by it. The time-to-live field is fully described when we look at the Traceroute program in Chapter 8, because this field is the basis for the operation of the program. Similarly, many features of ICMP are described in the later chapters, in terms of how a particular ICMP message is used by a protocol or an application.

We also don't want to save all the good stuff until the end, so we describe TCP/IP applications as soon as we have the foundation to understand them. Ping and Traceroute are described after IP and ICMP have been discussed. The applications built on UDP (multicasting, the DNS, TFTP, and BOOTP) are described after UDP has been examined. The TCP applications, however, along with network management, must be saved until the end, after we've thoroughly described TCP. This text focuses on how these applications use the TCP/IP protocols. We do not provide all the details on running these applications.

Readers

This book is self-contained and assumes no specific knowledge of networking or TCP/IP. Numerous references are provided for readers interested in additional details on specific topics.

This book can be used in many ways. It can be used as a self-study reference and covered from start to finish by someone interested in all the details on the TCP/IP protocol suite. Readers with some TCP/IP background might want to skip ahead and start with Chapter 7, and then focus on the specific chapters in which they're interested. Exercises are provided at the end of the chapters, and most solutions are in Appendix D. This is to maximize the usefulness of the text as a self-study reference.

When used as part of a one- or two-semester course in computer networking, the focus should be on IP (Chapters 3 and 9), UDP (Chapter 11), and TCP (Chapters 17-24), along with some of the application chapters.

Many forward and backward references are provided throughout the text, along with a thorough index, to allow individual chapters to be studied by themselves. A list of all the acronyms used throughout the text, along with the compound term for the acronym, appears on the inside back covers.

If you have access to a network you are encouraged to obtain the software used in this book (Appendix F) and experiment on your own. Hands-on experimentation with the protocols will provide the greatest knowledge (and make it more fun).

Systems Used for Testing

Every example in the book was run on an actual network and the resulting output saved in a file for inclusion in the text. Figure 1.11 (p. 18) shows a diagram of the different hosts, routers, and networks that are used. (This figure is also duplicated on the inside front cover for easy reference while reading the book.) This collection of networks is simple enough that the topology doesn't confuse the examples, and with four systems acting as routers, we can see the error messages generated by routers.

Most of the systems have a name that indicates the type of software being used: bsdi, svr4, sun, solaris, aix, slip, and so on. In this way we can identify the type of software that we're dealing with by looking at the system name in the printed output.

A wide range of different operating systems and TCP/IP implementations are used:

• BSD/386 Version 1.0 from Berkeley Software Design, Inc., on the hosts named bsdi and slip. This system is derived from the BSD Networking Software, Release 2.0. (We show the lineage of the various BSD releases in Figure 1.10 on p. 17.)
• Unix System V/386 Release 4.0 Version 2.0 from U.H. Corporation, on the host named svr4. This is vanilla SVR4 and contains the standard implementation of TCP/IP from Lachman Associates used with most versions of SVR4.
• SunOS 4.1.3 from Sun Microsystems, on the host named sun. The SunOS 4.1.x systems are probably the most widely used TCP/IP implementations. The TCP/IP code is derived from 4.2BSD and 4.3BSD.
• Solaris 2.2 from Sun Microsystems, on the host named solaris. The Solaris 2.x systems have a different implementation of TCP/IP from the earlier SunOS 4.1.x systems, and from SVR4. (This operating system is really SunOS 5.2, but is commonly called Solaris 2.2.)
• AIX 3.2.2 from IBM on the host named aix. The TCP/IP implementation is based on the 4.3BSD Reno release.
• 4.4BSD from the Computer Systems Research Group at the University of California at Berkeley, on the host vangogh.cs.berkeley.edu. This system has the latest release of TCP/IP from Berkeley. (This system isn't shown in the figure on...