At which layer of the OSI model are Media Access Control (MAC) addresses used?

Media Access Control (MAC) addresses are fundamental to the operation of a network at the Data Link layer of the OSI model. This layer is responsible for node-to-node data transfer and ensuring that data packets are correctly framed for transmission over a physical medium.

MAC addresses serve as unique identifiers for network interfaces, enabling devices within the same local network to communicate with each other. Each network interface card (NIC) is assigned a MAC address, which allows devices to send data to the correct recipient. The Data Link layer manages how data packets are placed on and received from the physical layer, handling error detection and correction, as well as frame synchronization.

The correct recognition of MAC addresses at this layer is crucial for local area networking (LAN), ensuring that data can efficiently find its way through the network to the intended recipient based on these unique hardware identifiers.