Now, let me disclaim that I am not a big fan of thin books claiming to be "comprehensive". In fact, I was deeply suspicious while getting this "Hacknotes" thing. Was I up for a pleasant surprise!! This book does deliver what it promises. It walks a fine line of being both wide and deep, which I am still amazed about. From risk assessment methodologies to "find / -perm 0400" in just 200 pages is no small feat.
I liked that the book and the entire series have a clearly stated goal, and readers can judge for themselves how well it delivered and there is no confusion as to "what should be there". The book is incredibly useful within those stated goals. Obviously, the book is not optimal for actually learning those methods and technologies, but it is an awesome reference in case you forget a thing or two or want to get an overview of a subject within network security. Unfortunately, the book will also benefit "script kiddies" by helping them to "hack without knowing how".
This includes high-level security principles, risk assessment (covering assets, threats and risks), hacking methodology (same as in "hacking Exposed") with details on all the attack stages (Discover, Scan, Enum, Exploit - split along the platform lines, Escalate, etc), wireless security, incident response (identification and recovery), pen testing and hardening. Amazing, but that is not all. It also covers web application security, social engineering, software flaws overview, war dialing and PBX hacking. Of course, all of the above is covered briefly, but thoroughly. Tools are mentioned where needed, and there is no excessive "tool obsession".
Yet another great component is several checklists. Those are used for incident response, security assessment and system hardening (Win, UNIX with some tips on specific servers - FTP, WWW, DNS, Mail etc). Additionally, the book has even more condensed part, "a reference center" with some handy commands from the worlds of DOS, Windows and UNIX/Linux. I liked a nice "important ports" overview.
Overall, unless you are just starting in infosec, get the book and it will come handy more often that you'd think.
Anton Chuvakin, Ph.D., GCIA, GCIH is a Senior Security Analyst with a major information security company. His areas of infosec expertise include intrusion detection, UNIX security, forensics, honeypots, etc. In his spare time, he maintains his security portal info-secure.org