Definition
Wireshark is a free and open-source network protocol analyzer used for network troubleshooting, analysis, software and communications protocol development, and education. It captures network packets in real time and displays them in a human-readable format, allowing users to inspect the data flowing across a network. This tool is essential for understanding network traffic patterns, identifying performance bottlenecks, and detecting security threats. For instance, a network administrator might use Wireshark to diagnose why a specific application is experiencing slow response times by examining the captured packets for retransmissions or high latency. While often confused with a firewall, which actively blocks traffic, Wireshark passively observes and analyzes network data without altering its flow. Knowledge of Wireshark is frequently tested on CompTIA Security+, CySA+, and CISSP exams.