When an aggregation switch receives data from access switches, it performs local routing, filtering, load balancing, and QoS priority management. It is essential for larger networks requiring efficient data flow. The primary function of an aggregation switch is to aggregate and forward data from multiple network devices, such as access. As the physical entity of the aggregation layer, the aggregation switch's primary function is to aggregate the data of the access layer switch and forward it to the core switch to reduce the burden on the core layer. The aggregation layer serves as the convergence point for multiple access layer switches and is responsible for handling all. An aggregation switch sits in the middle tier of a network, collecting traffic from multiple smaller access switches and funneling it upward to the core.