Final answer:
To test connector pins on a Network Interface Card's port, a loopback plug is commonly used. This tool performs a self-test of the network interface by sending a signal that loops back to the NIC.
Step-by-step explanation:
When troubleshooting problems with a Network Interface Card (NIC), a loopback plug can be used to test connector pins on the NIC's port. A loopback plug is a device that is plugged into a port on a computer to perform a self-test of the network interface. It sends a signal out through the network interface and then back to it, checking to see if the transmit and receive paths are working and if the pins on the connector are functioning properly.
Other tools mentioned, such as a multimeter, can be used to test for electrical problems like voltage and continuity but are not specific for NIC port pins. A cable tester is primarily used to test the integrity of cables rather than the NIC's port pins. A Time-Domain Reflectometer (TDR) is used to locate faults in cables and is not specifically designed for testing NIC ports.