Reasoning: A cable tester capable of testing Power over Ethernet (PoE) functionality can verify whether the switchport is providing the required power to the phone. This tool measures both the presence of data and the voltage or wattage being provided through the Ethernet cable.
This is the most effective way to confirm that PoE is available on the port.
Why the Other Options Are Incorrect:
A. Network tap:
A network tap is primarily used to monitor network traffic, not to test for PoE availability. It cannot verify if power is being supplied through the Ethernet cable.
C. Loopback plug:
A loopback plug is used to test the functionality of a network port by creating a loop for transmitted and received signals. It does not measure or verify PoE availability.
D. Toner probe:
A toner probe is used for tracing and identifying network cables. It cannot test for PoE functionality.
Practical Example:
A PoE phone might not turn on due to a misconfigured or faulty switchport. Using a cable tester capable of measuring PoE would help the technician determine if the switchport is supplying sufficient power to the phone.
CompTIA A+ Exam Objective Alignment:
Objective 2.1: Identify common networking hardware and tools, including PoE-enabled devices and cable testers.