The main function of a network protocol analyzer, also known as a packet sniffer, is to examine and analyze data traffic flowing through a network. This tool captures data packets and interprets their contents, enabling network administrators to troubleshoot issues, monitor performance, and enhance security. By analyzing protocols in real time, the analyzer helps detect anomalies, unauthorized access, and potential network breaches, thereby improving overall network performance and reliability. It is essential for maintaining the integrity and security of networked systems.