Final answer:
MAC addresses serve as unique physical identifiers for Ethernet network interfaces, facilitating communication and ensuring device recognition within the network at the data link layer. Thus the correct option is B.
Step-by-step explanation:
Every Ethernet network interface is assigned a Media Access Control (MAC) address, which serves as its unique physical address. Unlike IP addresses that identify devices on a network at the network layer, MAC addresses operate at the data link layer. MAC addresses are crucial for the proper functioning of Ethernet networks, as they facilitate the communication and identification of devices within the network.
A MAC address is a 48-bit hexadecimal number, typically represented in six groups of two digits separated by colons or hyphens. The first half of the MAC address is assigned to the device manufacturer, while the second half is unique to each device. This ensures that no two devices on a network have the same MAC address, allowing for accurate and secure communication.
Understanding the significance of MAC addresses is essential for troubleshooting network issues, ensuring network security, and managing network resources effectively. Networks rely on MAC addresses for the delivery of data frames, and knowing the MAC address of a device is crucial for tasks such as configuring network settings and implementing access controls.