CompTIA Network+ Practice Test

Which OSI model layer deals with Ethernet as a data link protocol?

1. Application

2. Session

3. Transport

4. Data Link

The correct answer is: Data Link

The Data Link layer of the OSI model is responsible for node-to-node data transfer and handles the physical addressing of data frames. It is crucial for the operation of local area networks (LANs) and is where protocols like Ethernet operate. At this layer, data packets are framed, and the MAC (Media Access Control) addresses are utilized to identify devices on the same network segment, facilitating proper transmission and reception of data. Ethernet, as a specific implementation of the Data Link layer, provides the means for devices in a LAN to communicate. It ensures that data is packaged into frames, includes error detection mechanisms, and manages access to the physical media, thereby making it essential for network connectivity in environments that use Ethernet technology. In contrast, the other layers, such as Application, Session, and Transport, are responsible for higher-level functions such as data presentation, session management, and end-to-end communication, which do not directly relate to the specifics of how data packets are framed and sent over a physical connection like Ethernet.