For any network that is either big or small, network monitoring and security is a very essential task. Regular monitoring of the network is important to protect systems from attacks and also to keep viruses and malware out of a network.
Nmap, short for network mapper, is a free and open source tool that monitors a network, and it is the most versatile tool used by system/network administrators. Nmap can be used to perform security scans, explore a network, find open ports on remote systems, and perform network audits.
To show how Nmap works, we need a minimum of two systems to form a small network. On one system, we will install the nmap package, while the other system will be used as a host to scan.