Which tool captures live network traffic for analysis and can be used defensively for troubleshooting and offensively for credential harvesting?

• A. Proxy
• B. VPN
• C. Intrusion Detection System
• D. Network Sniffers

Answer: (D)

Capturing live network traffic for analysis is what network sniffers do. They monitor a network segment by putting an interface into promiscuous mode or using a mirror/tap to copy packets as they flow, letting you inspect headers, payloads, timings, and protocol behavior in real time. This makes them incredibly useful for defensive troubleshooting—you can see where delays occur, identify misconfigurations, and diagnose failures by watching actual traffic patterns as they happen. They also carry inherent risk: if traffic includes plaintext credentials, a sniffer can reveal them, which attackers might exploit for credential harvesting. Encryption greatly mitigates this risk because readable passwords won’t be in the captured data.

Other tools don’t provide the same full-wire visibility. A proxy forwards and potentially logs traffic but doesn’t give you the complete picture of everything on the network segment. A VPN encrypts traffic between endpoints, hiding its contents from local sniffing. An intrusion detection system monitors and analyzes traffic for signs of malicious activity rather than capturing and inspecting every packet.

So, the ability to capture and analyze live network traffic on the wire is what makes network sniffers the best fit.