What is the primary function of a packet sniffer?

• A. To block unauthorized traffic using firewall rules.
• B. To capture and analyze network traffic for troubleshooting, performance monitoring, and security investigations.
• C. To route packets between networks.
• D. To replace encryption with unencrypted traffic.

Answer: (B)

A packet sniffer is used to capture and analyze network traffic. It listens to a network segment, collects the packets that travel by, and decodes headers and payloads so you can see who’s talking, what services are in use, and whether anything looks wrong. This makes it invaluable for troubleshooting lingering issues (like misconfigurations or dropped packets), monitoring performance (such as bandwidth patterns and latency), and conducting security investigations (detecting unusual or unauthorized activity). It doesn’t block or forward traffic, nor does it route packets between networks, and it doesn’t replace encryption with unencrypted traffic—its role is observational and diagnostic, not traffic control or decryption.