Once you’ve completed the footprinting phase and you’ve gath-
ered a good amount of information about your target, it’s time
to act on this information. This is the point where you try to
ascertain what assets the target has and what is of value.
The scanning process is possible in part because of the wealth of information you
gathered in Chapter 4, “Footprinting and Reconnaissance,” and how you are able to
interpret that data. Using information found on discussion groups, through e-mails, at job-
posting sites, and other means, you now have an idea of how to position your scan.
To successfully negotiate the scanning phase, you need a good understanding of
networks, protocols, and operating systems. I recommend that if your knowledge of
network and system fundamentals is shaky you go back and review Chapter 2, “System
Fundamentals,” before you proceed. This chapter brings forward some of that information,
but I will place our primary focus on scanning and gaining information, not on past topics.
To follow along in this chapter, you will need to download Nmap from
http://nmap.org for your operating system. Experience in using this util-
ity is essential to your successful completion of the CEH exam and to your
future role as an ethical hacker.What Is Network Scanning?
Networking scanning is a methodical process that involves probing a target network with
the intent of finding out information about it and using that information for attack phases.
If you have a command of network and system fundamentals, coupled with thorough
reconnaissance it is possible to get a reasonable picture of a network—in some cases, even
better than the victim has of their own network and environment.