Comments about oreilly Linux iptables Pocket Reference:

This book was designed to be a pocket reference and not as a how-to guide. While this book has some good explanations of the path a packet takes through the kernel, it do not tell you how to set up filtering rules. It is a good place to look something up quick. The tables with the protocol numbers and port numbers has been very useful for me, and I keep this book in my laptop case at all times. If you are considering whether to get this book or not, keep the following in mind. If you have a good understanding to tcp/ip, networking protocols, and a working understanding of iptables this book is a good reference guide. If you are not familiar with those concepts you should look for a better how-to guide or learning book.

Comments about oreilly Linux iptables Pocket Reference:

If this is your first time setting up the Linux packet filtering functions you will need to refer to other documentation. This pocket guide is most useful to someone who is already familiar with the workings of iptables. I do not recommend it for a beginner.

Little explanation is given in this guide on the theory of packet filtering and network address translation (NAT), and the examples, as is so typical of a lot of Linux documentation, make too many assumptions about the reader's knowledge. In particular, the NAT section is woefully inadequate -- I can glean more information about NAT from the ipfilters man page.

I was also disappointed in the typesetting of this guide. The font is too small and the font weight produces, in my opinion, a poor contrast between characters and paper. I struggled trying to read this guide in anything other than high light levels and concluded that I had wasted my money. I'll keep it here in my library (returning it would cost almost as much as it's worth) but it will probably gather a lot of dust.