Last year, I was forced to become a fly-by-night system administrator. I worked for a small, local startup as its web developer, but was thrust into a sysadmin role when my boss decided to host a website on a server in our office. I was developing the site on our Ubuntu server, but was learning how to secure the server on the fly. This reference, out of all the other books I read and sites I visited, had the most bang for the buck.

It's short and sweet. It describes what you should know, and gives you a reference for dealing with iptables syntax, and that's it. No flowery text, no colored pictures. Just simple "This is how to do X."

If you're a sysadmin, especially if you're just getting your feet wet, get this book. It's cheap, it tells you what you need to know, and it fits in your pocket. What's not to like?

Concise and very handy. Guides like these aren't meant to be a complete reference on iptables. Yet, the author managed to pack quite a bit into such a small book. 82pages from page 1 to beginning of index.

21 pages to theory and operation -- connection tracking, accounting, NAT, SNAT, DNAT, Transparent Proxying, load balancing, and stateless/stateful firewalls.

The next 61 pages are a command reference to iptables. It is in the command reference that you shall find interesting little nuggets like:

1) How to rate limit incoming traffic. Specific examples provide for allowing only 10 pings per second.

2) How to setup IP pools to match source and/or destination addresses. Instead of writing a line for each IP or netblock, throw the addresses into a pool and write a line for each pool.

3) How to match multiple ports on the same line.

and so on.

Worth every penny. Lives up to O'Reilly name. Would recommend for every Linux sysadmin.

Linux iptables Pocket Reference is a great book.

there is a dearth of info on Linux iptables, and this pocket reference is a great book!!

'Linux iptables Pocket Reference' is an important and sorely needed reference to iptables, the interface to the Linux packetfilter used by System Admins to create firewalls, NAT routers, transparent proxies, and other 'magical' network devices. While not a tutorial, it offers good advice for those with a grasp of basic networking concepts, and a good notion of what a firewall is and what it is used for, in a dense and concise format. Sufficiently detailed information about the protocols involved obviate the need to keep additional references at hand, and make the work relatively self-contained. This should not be the first book you read about firewalls or tcp/ip, but if you are a networking professional, a technically oriented user, or just interested in creating special purpose network devices, this book belongs in your library. Those familiar with iptables will especially appreciate the lucid description of packet flow through the tables and chains, and the supporting diagrams ... they alone are worth the price of purchase.

If you have need for a book on the topic, you will not be disappointed with this one.

This book is written for linux/unix sysadmins, not programmers. The topic of iptables is intimately related to guarding a network against intruders. A sysadmin task. Plus, the compact, pocketbook size lends itself to a common scenario.

You're a harried sysadmin in the machine room of your company, surrounded by racks of computers and cabling. Equipment everywhere and little room for you to prop up a regular sized text on intrusion detection. Quite possibly, the master console is some cheezy old monitor that you got stuck with. Or even worse, it is just a terminal. If the latter, it's really awkward to do a man on iptables and also run it, especially if you're in real time mode against an active intruder. In other words, what this book is ideal for.