No backboard

Which of these would be the best choice for testing a WAN interface?

A) Toner probe

B) Multimeter

C) Cable tester

D) Crimper

E) Loopback plug

F) H-O-R-S-E. Best two out of three.

The answer: E) Loopback plug

A loopback plug is used to test a physical interface. Data is sent out the transmit pins and the loopback plug sends all of the data back to the receive pins on the same interface. The data is compared to verify that the sent data is identical to the data received.

Want to know more? Watch “Common Networking Tools.”

There are many different types of devices that can connect to your computer, and many of them use completely different connectors. In this video, you’ll learn about the cables and connectors used for hard drives, USB devices, FireWire components, parallel links, serial connections, network links, and much more.