If we want to hack a computer, we must know a few things.

Before anything else, we need to know that the computer exists in the first place - it’s hard to hack a computer that doesn’t exist. We also need information about the computer, and the more we have, the better. At a minimum, we’ll want to know what operating system and software the computer is running so that you can start looking up potential exploits.

One of the ways we can gain information about computers is through Network Enumeration (also known as Network Scanning). Network enumeration is an incredibly useful reconnaissance tool that can tell us what computers exist on a network and provide information about what those computers are. We can think of network enumeration like sonar or radar, sending out a pulse (or a packet of data in this case) and seeing what comes back. Also, like sonar and radar, network enumeration can make a lot of noise, and doing it recklessly will alert defenders to your activity.

Network enumeration can also be used for defensive or utility purposes, such as creating network diagrams or finding misconfigured computers.