Which of the following is used to confirm that a physical port is working?

The correct answer is D. Loopback plug. A loopback plug is a diagnostic tool used to test the functionality of a physical port (e.g., Ethernet, serial, fiber) by routing the output signals back into the input. This simulates a network connection and allows a technician to verify that the port's internal transmission…

Submitted by valeria.br· Mar 30, 2026Hardware and network troubleshooting

Question

Options

ANetwork tap
BCrimper
CPatch panel
DLoopback plug

How the community answered

(61 responses)

A
2% (1)
B
3% (2)
C
5% (3)
D
90% (55)

Explanation

A loopback plug is a diagnostic tool used to test the functionality of a physical port (e.g., Ethernet, serial, fiber) by routing the output signals back into the input. This simulates a network connection and allows a technician to verify that the port's internal transmission and reception hardware is working correctly. If data is sent out and received back without errors, the physical port is considered functional.

Topics

#loopback plug#port testing#network diagnostics#cable testing

Community Discussion

No community discussion yet for this question.

Full 220-1201 Practice