Which identifier is assigned to network interfaces for communications at the data link layer?

Which identifier is assigned to network interfaces for communications at the data link layer?

• A. IP address
• B. MAC address
• C. 2.4GHz
• D. Band options

Answer: (B)

Communications at the data link layer rely on a hardware identifier that uniquely marks each network interface on the local segment, allowing devices to address frames within the same LAN. This identifier is the MAC address, a unique hardware address assigned to a network interface card. Frames on Ethernet carry source and destination MAC addresses, guiding delivery within the local broadcast domain. IP addresses, by contrast, operate at the network layer to route packets between networks, not to deliver within a local link. The 2.4GHz frequency or wireless band options are not identifiers for devices; they describe radio characteristics, not addressing. Therefore, the identifier assigned to network interfaces for data link layer communications is the MAC address.

Communications at the data link layer rely on a hardware identifier that uniquely marks each network interface on the local segment, allowing devices to address frames within the same LAN. This identifier is the MAC address, a unique hardware address assigned to a network interface card. Frames on Ethernet carry source and destination MAC addresses, guiding delivery within the local broadcast domain. IP addresses, by contrast, operate at the network layer to route packets between networks, not to deliver within a local link. The 2.4GHz frequency or wireless band options are not identifiers for devices; they describe radio characteristics, not addressing. Therefore, the identifier assigned to network interfaces for data link layer communications is the MAC address.