Which is true about hardware MAC addresses?

Hardware MAC addresses serve a fundamental role in network communication, specifically in the data link layer of the OSI model. The primary purpose of a MAC address is to serve as a unique identifier for network interfaces on devices. Each network interface card (NIC) is assigned a MAC address that is intended to be globally unique, allowing devices on the same local network to distinguish between one another. This uniqueness is essential for devices to communicate effectively without confusion.

While it is possible for MAC addresses to be changed through software techniques or certain configurations, this is not the intended use; they are generally hard-coded into the hardware during manufacturing, which is why they serve as reliable identifiers. MAC addresses are not the same as IP addresses, as IP addresses may change depending on the network configuration and they operate at a higher level in the OSI model.

In summary, the truth about hardware MAC addresses lies in their function as unique identifiers for network devices, which is critical for managing data transfer on local networks.