Aggregation switches are widely deployed in high-traffic environments, such as enterprise backbones, data centers, and large campus networks, where they serve as a bridge between the access and core layers. The content of this chapter focuses on the aggregation layer design with the Cisco. What Is an Aggregation Switch? An aggregation switch is a network device that consolidates traffic from multiple access switches, wireless access points, or other edge devices and forwards it to core switches or routers. By bundling multiple network connections into a single high-bandwidth link. An aggregation layer usually comprises a few blocks of two switches in MCLAG. By design, it therefore provides resiliency because it will always be deployed in pairs of switches and comes with a recommendation to deploy only dual hot swappable power supplies and redundant fans in each switch to. Core switches set up a CSS that functions as the core of the entire campus network to implement high network reliability and forwarding of a large amount of data. A key characteristic of these leaf-spine switching networks is that all leaf switches have full meshed connectivity to the spine switches.