To detect a sniffer on a network, identify the system running in promiscuous mode; which method is described as useful for detection?

To detect a sniffer on a network, identify the system running in promiscuous mode; which method is described as useful for detection?

• A. Ping Method
• B. ARP Method
• C. Social engineering
• D. Scarcity

Answer: (A)

The technique being tested relies on actively probing the network to reveal a host that is capturing all traffic. The Ping Method uses ICMP echo requests (pings) to the devices on the local subnet and then analyzes the responses and the traffic pattern that results. A machine whose NIC is in promiscuous mode will often show up in the network’s discovery data differently than a normal host, because it receives and processes all frames on the wire, not just those addressed to it. By performing a targeted ping sweep and comparing the observed responses or timing with what you expect from known, properly configured hosts, you can identify the system that’s listening to all traffic. This approach is practical because it is lightweight, uses standard tools, and doesn’t require specialized exploits or social engineering. It focuses on how active probing can expose anomalies in how a particular host participates in network traffic. The other options are not suited for this technical detection goal: social engineering targets people rather than network behavior, and scarcity isn’t a method for detecting promiscuousNICs. The ARP-based approach can be more complex or less reliable in some environments, whereas the Ping Method provides a straightforward way to surface a candidate host running in promiscuous mode through routine network probing.

The technique being tested relies on actively probing the network to reveal a host that is capturing all traffic. The Ping Method uses ICMP echo requests (pings) to the devices on the local subnet and then analyzes the responses and the traffic pattern that results. A machine whose NIC is in promiscuous mode will often show up in the network’s discovery data differently than a normal host, because it receives and processes all frames on the wire, not just those addressed to it. By performing a targeted ping sweep and comparing the observed responses or timing with what you expect from known, properly configured hosts, you can identify the system that’s listening to all traffic.

This approach is practical because it is lightweight, uses standard tools, and doesn’t require specialized exploits or social engineering. It focuses on how active probing can expose anomalies in how a particular host participates in network traffic. The other options are not suited for this technical detection goal: social engineering targets people rather than network behavior, and scarcity isn’t a method for detecting promiscuousNICs. The ARP-based approach can be more complex or less reliable in some environments, whereas the Ping Method provides a straightforward way to surface a candidate host running in promiscuous mode through routine network probing.