Which term describes the unique hardware address assigned to a network interface for local network communications?

• A. MAC address
• B. IP address
• C. DNS name
• D. Subnet mask

Answer: (A)

The unique hardware address assigned to a network interface for local network communications is called the MAC address. This identifier, embedded in the network interface hardware, is used at the data link layer to deliver frames within a single local network segment. Devices on the same local network use MAC addresses to ensure frames reach the correct NIC, and switches rely on them to forward traffic appropriately. MAC addresses are typically fixed for a given physical adapter, usually shown as a 48-bit hexadecimal value, and they remain constant unless spoofed or changed in virtualization scenarios.

In contrast, an IP address is a logical address used for routing packets between networks, not for local frame delivery. DNS names are human-readable identifiers that map to IP addresses, not hardware identifiers. Subnet masks define which portion of an IP address refers to the network versus the host, and are part of IP addressing, not a hardware address.