Introduction to network scanning :
Network scanning is an extended form of Reconnaissance. The process aims to gather information on hosts, ports and services in a network. This information helps to profile hosts in a network. The objectives of network scanning are summarised below.
- To find live hosts, IP address and ports
- To find services running on hosts
- To discover operating systems and versions of services
- To find vulnerabilities in hosts
Scanning process is classified into port scanning, network scanning and vulnerability scanning. Port scanning lists ports and services by probing or connecting to TCP and UDP ports on host system. Network scanning lists IP adresses of all the hosts in target network. Vulnerability scanning is for checking known exploitable vulnerabilities.
