What kind of address is utilized to identify devices on an Ethernet network?

In an Ethernet network, the address used to identify individual devices is the MAC address. A Media Access Control (MAC) address is a hardware identifier that is embedded into the Network Interface Card (NIC) of a device. This address is unique to each device, allowing for precise identification and communication on the local area network (LAN).

MAC addresses operate at the data link layer (Layer 2) of the OSI model and are essential for the Ethernet protocol, as they facilitate device communication within the same local network. When a device wants to send data to another device on the same Ethernet network, it uses the recipient's MAC address to ensure that the data is delivered to the correct destination.

In contrast, while IP addresses (which operate at Layer 3) are critical for routing data across different networks, they are not used specifically for device identification within a single Ethernet network. Subnet addresses and gateway addresses serve different purposes related to network routing and addressing, but neither is used to uniquely identify devices at the Ethernet level. Thus, in the context of identifying devices within an Ethernet network, the MAC address is the correct and relevant choice.