Which of the following is the main purpose for a MAC address to identify?

A MAC (Media Access Control) address is a unique identifier assigned to network interfaces for communication on the physical network segment. It is used to identify a specific piece of hardware, such as a network card or a network interface within a device. MAC addresses are crucial in ensuring the proper routing of data on local networks, functioning at the data link layer (Layer 2) of the OSI model.

A. A user is identified through user accounts, not hardware-level MAC addresses.

C. An IP address identifies devices on a network but operates at Layer 3 (Network Layer), while MAC addresses work at the hardware level.

D. A network is identified by an IP address or a subnet, not by a MAC address.

References:

CompTIA Network+ Certification Objectives

Official CompTIA A+ Study Guide