An aggregation switch operates at Layer 2 or Layer 3 of the OSI model, depending on the configuration and topology of the network. The controller uses protocols, such as Link Aggregation Control Protocol (LACP) or Static Link Aggregation, to combine physical links into a single. Knowing the roles of core, aggregation, and access switches in contemporary network topology becomes essential to create effective and scalable networks. The Cisco three-layer hierarchical model provides recommendations for designing campus LANs. Each layer is served by specialized switches, with the access switch connecting end-user devices, the distribution switch aggregating traffic and enforcing policies, and the core switch acting as.