Review of Cisco TCP/IP Routing Professional Reference

Cisco TCP/IP Routing Professional Reference
Chris Lewis

Reviewed by Nick Christenson,

November 12, 1997

Despite the dominance of Cisco in the routing market, the incredible number of router devices deployed, and the scarcity of professionals truly skilled in configuring and maintaining these devices, there has been a scarcity of reference works on Cisco routers outside of Cisco's own documentation. In fact, this book is the first work published outside of Cisco's documentation that covers configuration of routers in any detail. Finally, this gap in the literature has been filled.

The book jumps right in to discuss the basics of routers, comparisons to bridges, and how to get the router out of the box and ready for configuration. In the second chapter, we take a step back and review TCP/IP. This introduction is necessary in a book like this which aims to satisfy the needs of beginners, this delivery is pretty routine and unremarkable.

With Chapter 3, we get right in to configuring the router, covering issues such as bootstrapping the config and loading the configuration from flash memory, the network, or typing it in by hand. Also discussed is the importance of setting up a lab or test network for learning and experimentation. This is an important issue and its presence here is appreciated. Chapter 4 covers basic routing protocols, RIP, OSPF, IS-IS, IGRP, and EIGRP. Also covered is static routing, but I believe this technique is not pursued with the vigor it deserves. Static routing has some distinct advantages (some of which are explored in Managing IP Networks With Cisco Routers by Scott Ballew) which deserve to be championed.

Chapter 5 talks about supporting "legacy LANs", which in this book means "anything that's not IP". This is a really good and important chapter, though, as there are still a lot of IPX, SNA, et. al. networks out there, and it's still somebody's job to support them.

The next chapter discusses WAN technologies, focusing on slower speed networks like Frame Relay, SMDS, and X.25. It would seem that the logic is that folks with, for example, multiple T3s or ATM networks would already have someone on staff to maintain the router who doesn't need to read this book. I believe this is an unfounded assumption, especially in today's Internet. One of my biggest criticisms of this book is that it really shies away from high end concerns. HSSI, ATM, BGP, and security issues are entirely welcome in a volume like this.

Chapter 7 is a big one that's all over the map. An awful lot of the meat of this book is contained here, and while it is very useful information, we would have been better served if there were more detail split into several chapters. Some of the issues covered are whether to use an RFC 1918 address space or not, configuring a Cisco router as a firewall, data compression, and SNMP. Clearly, each of these is a very deep topic. At the very least, suggestions on where the reader might turn for more detail would be appreciated.

The final chapter is on troubleshooting. Again, this is a very big topic and its impossible to cover everything, but Lewis does a good job of providing a framework for a general analysis of networking problems.

Overall, Cisco TCP/IP Routing Professional Reference is an excellent introduction to the topic of Cisco routing. The topics covered are clear and the basics are well covered. For someone with little experience who needs to maintain a Cisco router, this book would be extremely valuable and I'm happy to recommend it as such. Nonetheless, I was disturbed by some of the omissions.

In general, the book seems to cover routing state of the art as of five years ago, but there have been some very significant changes that, in my opinion, are absolutely necessary. The first is the issue of classless routing (CIDR). I couldn't find this critical topic mentioned once in the entire book.

Another shortcoming is on the topic of firewalls. Even though one is instructed on how to set up access lists, the discussions on methodology are neither sufficient nor state of the art. There is mention of neither IP spoofing filters, nor distinctions between input and output filters. The readers would be better served by a more thorough description on how to set up various kinds of filters and then strongly referred to a different source for information on general firewall implementation philosophies, such as Chapman and Zwickey's excellent Building Internet Firewalls.

A curious shortcoming, given that the author hails from the United Kingdom, is the US-centric view of networking. Most of the concepts can be applied to E1 circuits in the same way that one would apply them to T1 lines, nonetheless, I would not have minded a more international viewpoint.

There are some fairly minor editorial problems with the book, nothing extreme, but more than one would like. Most of the problems occur early in the book and have to do with missing spaces in examples, which can be misleading. The reader would be well advised to look out for them.

Despite these criticisms, this is still a very good and useful book. Beginners needing a reference on Cisco routers would be well advised to pick it up and read it carefully, although they should keep in mind that it does not include everything they probably want to know. Matched with Ballew's Managing IP Networks With Cisco Routers, which is long on good design principles but shy on the configuration details, it becomes even stronger.


A very good basic book on configuring Cisco routers, this book fills an important gap in the literature. Despite some significant shortcomings, it is still a worthwhile acquisition, especially for novice router administrators.