You’re having problems with a serial port on your laptop, and your diagnostics software needs an external tool to help complete the testing. Which of these tools is often used for testing physical ports?
A) Crossover cable
B) Loopback plug
C) Cable tester
D) Torx driver
E) Garden weasel
The answer: B) Loopback plug
A loopback plug is a small device that plugs into an interface port and redirects all traffic sent from the interface back into the receive ports on the interface. Loopback plugs are often used in conjunction with diagnostics software that will send specific traffic patterns out the port and examine the incoming traffic to ensure it matches.
Want to know more? Watch “The A+ Toolbag.”
A well-equipped toolbag is an important part of any CompTIA A+ certified professional. In this video, you’ll learn which tools can help you with your day-to-day installation and troubleshooting tasks.