I am looking for a book/website/blog etc., about hacking computer networks. I don’t mean things like social engineering/SQL injection/exploiting server configuration, but hacks at protocol level, like injecting packets, Ethernet level network protection etc. I am really interested in computer security, but this area is still black magic to me and I want to develop my skills in it.
I know this question may seem a little bit too general to ask on Stack Overflow, but it’s really difficult to find broad materials about this narrow area.
I don’t know what are your programming skills, but I found these books very helpful for myself:
Counter Hack Reloaded – A Step-by-Step Guide to Computer Attacks and Effective Defenses it is more network oriented and perhaps most interesting to you
Hacking : The Art of Exploitation, 2nd Edition has a deeper background and gives you quick introduction to machine code and C programming language. Also I like the second one because it comes with a linux ISO and source code for all examples in the book to play around with
Also there are plenty of website full of material, tutorials and playground, just google for computer security/hacking tutorials. For example take a look at these two ones
http://www.securitytube.net/ is a website where you can find a lot of material including video tutorials. They also offer training and certifications.
http://smashthestack.org/ is a website where you can practice your skills. It has different categories of games that comprise various levels; you start at first level and once you solve it/ hack it you get access to the next level.