The aggregation switch connects to two cores
Chassis aggregation is a Cisco technology to make two switches operate as a single logical switch. By bundling multiple network connections into a single high-bandwidth link, aggregation switches help. 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. An Aggregation or "Top-of-Rack" switch is designed to connect everything in a rack at high speeds, then have an even bigger pipe out to the rest of the network.
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