Palo Alto Networks (PANW) Certified Cybersecurity Entry-level Technician (PCCET) Practice Exam

Which layer of the OSI model ensures that messages are delivered to the proper device across a physical network?

1. Application

2. Data Link

3. Network

4. Presentation

The correct answer is: Data Link

The Data Link layer of the OSI model plays a crucial role in ensuring that messages are delivered to the correct device on a physical network. This layer is responsible for node-to-node data transfer and handles error detection and correction that may occur during transmission. It defines how data packets are framed and the method to access the physical medium, making it essential for identifying devices on the local network through physical addresses (like MAC addresses) and facilitating communication between them. This layer operates just above the Physical layer, which deals with the transmission of raw bitstreams over a medium, and below the Network layer, which is focused on delivering packets across multiple networks. Its primary function is to ensure that data sent from one device can be received correctly by another, using mechanisms like MAC addressing to specify the destination and manage data flow. In comparison, the Application layer interacts directly with user-level applications, the Network layer focuses on routing data across multiple networks, and the Presentation layer is concerned with data translation and formatting. These layers do not handle the specifics of delivering messages to individual devices on a local network, which is the key responsibility of the Data Link layer.