A MAC address is permanently embedded on the NIC.

A MAC address is permanently embedded on the NIC.

• A. A MAC address is permanently embedded on the NIC.
• B. An IP address is permanently embedded on the NIC.
• C. A MAC address can be changed by software.
• D. A MAC address is assigned by DNS.

Answer: (A)

MAC addresses are hardware identifiers built into the NIC by the manufacturer and stored in the card’s non-volatile memory. This makes the address a unique, physical label that the device uses at the data-link layer to communicate on a local network. Because it’s embedded in the hardware, it remains with the NIC across reboots and power cycles. Some systems can override this value in software to temporarily change how the device presents itself, but the underlying, physical MAC on the card is the default identifier assigned by the vendor. An IP address, in contrast, is a network-layer address assigned by DHCP or configured manually and can be changed easily, which is why it isn’t described as permanently embedded on the NIC. DNS has nothing to do with MAC addresses; it maps hostnames to IP addresses, not hardware identifiers.

MAC addresses are hardware identifiers built into the NIC by the manufacturer and stored in the card’s non-volatile memory. This makes the address a unique, physical label that the device uses at the data-link layer to communicate on a local network. Because it’s embedded in the hardware, it remains with the NIC across reboots and power cycles. Some systems can override this value in software to temporarily change how the device presents itself, but the underlying, physical MAC on the card is the default identifier assigned by the vendor.

An IP address, in contrast, is a network-layer address assigned by DHCP or configured manually and can be changed easily, which is why it isn’t described as permanently embedded on the NIC. DNS has nothing to do with MAC addresses; it maps hostnames to IP addresses, not hardware identifiers.