Port Scanning
Port scanning is a method of determining which Port|ports on a network are open and could be receiving or sending data. It is also a process for sending packets to specific ports on a host and analyzing responses to identify vulnerabilities.
This scanning can’t take place without first identifying a list of active hosts and mapping those hosts to their IP address. This activity, called host discovery, starts by doing a network scan.
The goal behind port and network scanning is to identify the organization of IP addresses, hosts, and ports to properly determine open or vulnerable server locations and diagnose security levels. Both network and port scanning can reveal the presence of security measures in place such as a firewall between the server and the user’s device.
After a thorough network scan is complete and a list of active hosts is compiled, port scanning can take place to identify open ports on a network that may enable unauthorized access.
The general protocols used for port scanning are Transmission Control Protocol|TCP (transmission control protocol) and User Datagram Protocol|UDP (user datagram protocol). They are both data transmission methods for the internet but have different mechanisms.