What is a Fluke LinkRunner and what does it do?

• A. A handheld oscilloscope for debugging
• B. A network multimeter used for troubleshooting and testing the physical and data link layers of a network
• C. A thermal camera for electrical components
• D. A power quality meter

Answer: (B)

The Fluke LinkRunner is a handheld network tester designed to troubleshoot and verify copper Ethernet cabling and network links. On the physical layer, it checks wiring correctness, continuity, pin-out, and detects issues like opens, shorts, miswires, or split pairs, often including cable length estimates. On the data link layer, it verifies that a link to a device (such as a switch port) is up, checks that the port negotiates correctly, and can test basic network reachability (and PoE presence if supported). It combines wiring verification with quick network reachability tests to confirm both the physical cable and the network connection are functioning. This is why it’s described as a network multimeter for troubleshooting the physical and data link layers, unlike tools intended for oscilloscopes, thermal imaging, or power quality.