Author – Natalia Wadden
Matrix Reloaded, Bourne Ultimatium and a brief glimpse in Girl with the Dragon Tattoo – these are just a few movies which feature a port scanning technique called nmap.
Before we go to far, let’s define nmap. It sounds glamorous, it must be, it is featured in at least 3 major Hollywood films. Nmap aka Network Mapper is a security scanner that is used to detect hosts and services on a computer network – in short it can determine which ports are open, what the operating system (OS) and version is, services that are offered, and what firewalls are used – basically it can create a map of the computer network and hosts.
Nmap is portable, it can be used across multiple platforms, Windows, Mac and Linux, but it is most commonly used in Linux. For this article, I will be using Kali Linux, it’s easy and many tools are already built into the OS. My mentor described ports as windows in a building, which means that nmap is looking for the open windows aka ports. So let’s dive in and scan our test machine and see if we can find any open ports.