Their main function is to aggregate traffic from the access layer, enforce policies, and forward data to the core layer. In traditional enterprise networks, the term distribution switch is commonly used, while aggregation switch is more prevalent in modern campus and data center. The three layers of a traditional three-layer network design are the core layer, aggregation layer, and access layer. Together, these layers can offer consumers a network that is safe, reliable, and affordable. As the physical part of the aggregation layer, aggregation switches typically play a. Switch aggregation refers to the concept of consolidating multiple access layer switches into a single aggregation layer switch in a traditional three-tier network design. It facilitates the connectivity because it would rapidly become impractical to.