Which layer of the OSI model does a VLAN operate on?

A VLAN, or Virtual Local Area Network, operates at the data link layer of the OSI model. This layer is responsible for node-to-node data transfer and handling the physical addressing of data packets. VLANs specifically segment a physical network into multiple logical networks, which allows for better management and traffic segregation without requiring separate physical switches.

By implementing VLANs at the data link layer, network administrators can control broadcast domains, improve security, and optimize network performance. It allows devices on the same physical network to be grouped logically as if they were on separate networks, even if they share the same physical infrastructure. This functionality is essential for efficiently managing network resources in larger and more complex networks.

The other layers mentioned—network, transport, and application layers—involve different functions such as routing between networks, end-to-end communication, and application-specific protocols. While all layers work together in a network, it's the data link layer that provides the framework for VLAN operation.