The correct answer is: TRUE.
MAC addresses are unique identifiers assigned to network interfaces for communications on the physical network segment. They are useful in diagnosing network issues because they can be used to identify specific devices on the network. This information can be used to track down the source of problems, such as a device that is not responding or is causing congestion.
MAC addresses are also useful in troubleshooting network problems. For example, if a device is not connecting to the network, the MAC address can be used to determine if the problem is with the device itself or with the network configuration.
In conclusion, MAC addresses are very useful in diagnosing and troubleshooting network issues. They can be used to identify specific devices on the network and to track down the source of problems.