Why are scanners so important for the security of networks?. Basically because they are essential tools for those who want to attack a system. There are several scanning tools for this purpose, but the article will look at nmap only. Nmap is among the most complete scanners and security tools.. . .
Why are scanners so important for the security of networks?. Basically because they are essential tools for those who want to attack a system. There are several scanning tools for this purpose, but the article will look at nmap only. Nmap is among the most complete scanners and security tools.

Nmap allows the system administrator to scan the networks, in order to know which servers are active and which services they offer. For this purpose, nmap offers several scanning techniques. This article will work on a limited number of them, reviewing (maybe teaching?) some aspects of TCP protocol.

The strategy in this article will be to show some of the more common ways to use nmap, to obtain information about systems and, in parallel, show how to find prints of the scanning on the target side.