Definition
Sniffing, also known as packet sniffing or network sniffing, is the act of intercepting and logging network traffic that passes over a digital network or part of a network. A network sniffer, or packet analyzer, captures data packets as they travel across the network, allowing for detailed inspection of their contents. This technique is invaluable for network troubleshooting, performance analysis, and security monitoring by revealing the flow of information. For instance, a network administrator might use sniffing to diagnose why a specific application is experiencing slow response times. It is distinct from port scanning, which probes for open ports rather than analyzing actual data transmission. Understanding sniffing is crucial for several cybersecurity certifications including CompTIA Security+ and Network+.