Customer Reviews

Interconnections: Bridges, Routers, Switches, and Internetworking Protocols (2nd Edition)

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3 star:		(2)
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If you are looking for a highly readable, but technical book on computer networking, this one is great. It contains some material on hardware, but it is mostly about algorithms and protocols. The author is one of the world's most respected authorities on the subject, having invented some of the key protocols and algorithms herself. Unlike many experts, however, she is able to explain the material in a straightforward way, making it accessible to anyone with a good technical background and an interest in the subject. The final chapter, on protocol design folklore, is unmatched anywhere. It gives tremendous insight into how to design a protocol and what can go wrong if you are not careful. This chapter is well worth the price of the book alone and"must" reading for anyone actually planning to design a protocol.

There are moments when this book reads like a detective story with drama, plot, and humor but even when Radia Perlman is simply working through the details of internetworking protocols the writing is clear and crisp. The chapters are well organized and diagrams are used very effectively to make even dense concepts accessible.

What I liked best about Interconnections was being consistently able to understand what the author was saying. While an electrical engineer might get a little more out of her discussions than I did I never felt locked out because my undergraduate education was in the liberal arts.

The material she presents is not always easy. In fact, Radia notes, "Anyone who isn't confused about when routers become EGP neighbors and what the rules are for configuring routers to initiate being EGP neighbors does not understand EGP" (p. 428). And yet the reader who is willing to concentrate and follow her lead can understand everything covered.

Even though this is a marvelously written book it is not for everyone. I would hesitate to recommend it to a network technician wanting to understand networks more fully. While I think every computer science student should spend two semesters working through these 18 chapters, memorizing the Glossary, and discussing the suggested homework problems the book is overkill for the ordinary MCSE candidate wanting to master Networking Essentials for a Microsoft certification exam. Interconnections is foundational reading for those who would design protocols or vendor equipment designed to interoperate with protocols but it is a bit much for someone who just wants to know which port to plug the cable into.

While Interconnections is not for everyone, I think it is essential reading for anyone who makes purchase decisions in an enterprise network. Without a firm understanding of bridges, routers, switches, and internetworking protocols they become far too vulnerable to sales techniques. And Interconnections is an essential reference for the Network Analyst. Radia notes that in the first edition of her book she assumed people would read the RFCs to get details that she omitted but they didn't. As someone who has spent some time trying to digest RFCs I am grateful that she bulked up the Second Edition with what she thought people needed to know. I can figure out what she writes but frequently feel I have wasted the effort when trying to get what I need out of the RFCs. Interconnections is a convenient one stop resource for researching packet headers and the various control messages that analyzer software may capture while sniffing a network to identify problems.

Interconnections, Second Edition is 150 pages larger than the First Edition published in 1992. Radia has reorganized, rewrote, added examples, included new protocols and more fully documented details to make it a better reference book. The Glossary was expanded from 4 pages to 10 but that was not enough. Radia does a good job of defining terms in the body of the book the first time they are used but not again in later chapters. When they are not in the Glossary it leaves the reader having to page around looking for the first definition. And the Index shrank from 15 pages to 5 between the First and Second Editions and thus became less useful for finding obscure terms.

Radia Perlman proposes that, "Before we design a solution, it's often useful to define the problem to be solved" (p. 505). To explain a protocol in the book she typically presents a list of problems and then walks through adding features to an algorithm to solve one or more of them. She discusses how adding one feature may create new problems. It is fascinating to do this exercise in relationship to real world protocols that are used everyday and to realize that some problems could be relieved if standards bodies could more readily agree. And that brings up one of the most enjoyable aspects of Interconnections, Radia sharing anecdotes and criticisms from years of participating on the Internet Engineering Task Force.

One take home message for me from reading Interconnections is that it is always best to keep it simple. Added complexity rarely pays off in anything but trouble. Radia opined, "I think people should be grateful if their packets get there at all" (p.202) rather than jumping through a lot of hoops to insure optimal routing. This is a good message for those who build internetworking protocols as well as those who just plug cables into ports.

The 2nd edition of Interconnections is every bit as good as the exceptional 1st edition, but is expanded by about 50%. Still present is Dr. Perlman's clear, concise coverage of the theory and practice of the fundamental network building blocks: bridges, routers, and "switches" (including token ring source-route bridging). Also still included is a brief synopsis of her dissertation on sabotage-proof network protocols, an idea whose time has definitely come. The coverage on specifics of network protocols is significantly expanded, particularly TCP/IP (v4 and v6), IPX/SPX, DECnet, and AppleTalk. Coverage of specifics of routing algorithms, such as RIP and OSPF, is also expanded, now even including multicast extensions. New material has been added that lays bare the details of fast ethernet, gigabit ethernet, ATM ("classical" IP-over-ATM and LANE), and NAT/NAPT. I highly recommend the 2nd edition to anyone wanting to increase their technical understanding of networking, no matter what your knowledge/experience level, and as a nonpartisan technical reference for networking professionals.

This book covers a wide range of topics in packet switching, both routers (layer 3) and bridges (layer 2). While there are other books that cover routing well, books about bridging are much harder to find. Radia discusses the two side by side, showing similarities and differences, drawbacks and benefits of each.

If you're used to the traditional dry and impersonal textbook style, this book will come as a refreshing surprise. You will get lots of facts -- and also opinions. If Radia thinks some particular technique is not a good thing, she'll simply say "I think this is a mistake". Nice.

The book covers both recent practice and historical background. Learning how these protocols evolved will help the reader understand why they now look the way they do. And discussions of "lessons learned the hard way" shows what design principles are important for reliability. The final chapter "Protocol design folklore" is a valuable addition to this second edition.

Many networking books are little more than condensations of product literature and standard documents. Radia's book goes into the concepts and principles behind the technology, and in some cases, the history. This information will be very useful to students learning the technology, networking managers trying to improve their networks and product developers hoping to avoid past mistakes. If network architects and standards developers absorb this book perhaps the next generation of networking will be less complex and more effective. The book includes historical anecdotes and controversial recommendations. These make it entertaining as well as informative.

Interconnections, Second Edition did something I didn't think was possible: it was better than the First Edition!

I personally like Radia Perlman's style. She writes in a way that flows for easy reading. Her material can appear to be technical, but unlike most technical material, you actually WANT to read more!

What I found most profound about this book is the fact that all major protocols are covered. There are comparisons performed between the protocols, such as IPv4, IPv6, CLNP, IPX, DECnet, etc. I have never seen this type of comparison anywhere! This alone is a wealth of knowledge that I can't underestimate.

Since I find myself also performing design work on behalf of numerous customers, the insight into why a choice was made during a protocol design is very interesting, and quite the learning experience.

Finally, Radia's humor is amazing. Her truth and personal opinions (and lets face it, with her history and influence on this industry, she is one of the few that has any right to criticize others in this industry) of how standards were derived is insightful and just plain fun to know!

I would recommend this book to anyone that wishes to know more about networking, to get a nice comparison of the differening protocols, and to learn a nice historical perspective of why things are as they exist today...

In my opinion, this book is a must read for everybody who wants to understand how networks work.

The explanation of the networking philosophies as well as individual technologies is exceptional. Reading this book is as easy as reading a novel.

Whether you work with network equipment by individual vendors, do a network related research or study networking -- get this book!

I work in the intrusion detection field, and I approached this book as a definitive and highly-respected guide to internetworking. "Interconnections" contained more than I bargained for. If you're looking for a reference work that extends well beyond IP, and collects information for comparison and posterity's sake, this tome is for you. If you're looking for more of an introductory to intermediate text, with more of an IP focus, either look elsewhere or scour this book for what you need. I did find it highly refreshing to read the words of a true master of the networking profession, and her candid evaluations of protocols, committee decisions, and failures of common sense. I was especially pleased to absorb the clarity of her opinions on layer 2 vs layer 3 switching, and all the vendor/committee mislabelling that follows! (Is it a bridge, router, etc.?) Enjoy!

If you want to truly understand about networks, you should buy this book. The author is very sacarstic and funny, so the reading is very pleasant. While in many books the author seems to not know the subject, this author REALLY knows what she is talking about. A must-have.

I have just recieved this book yesterday , as this book lives to the expectations , I havent read a better book to understand about Layer2 , there are lots of books available for Routing and understanding of Routable Protocols , this book goes quite in depth on Framing , Bridging , VLAN , etc.
This book is a must have for any one who wants to master Switching , and for anyone who wants to pursue CCNP and CCIE R/S track .

Navin Parwal
MCSE, CCNP ,CCDP, CQS1