Core and Aggregation Switches

The Gateway to Your Network
Core switches provide high-speed switching for all data flowing in and out of your organization’s data center. They serve as a gateway to the corporate wide area network (WAN) or internet. This core layer provides connectivity to multiple aggregation modules and provides a resilient Layer 3 fabric. At the core layer, reliability, high throughput and high performance are critical.

Providing Redundancy From Access to Aggregation
The aggregation layer, with many access layer uplinks connected to it, has the primary responsibility of aggregating the thousands of sessions leaving and entering the data center. The aggregation switches must support many 10 Gigabit Ethernet (10GbE) and 1GbE interconnects while providing a high-speed switching fabric with a high-forwarding rate. The aggregation layer also provides value-added services, such as server load balancing, firewalls and secure sockets layer (SSL) offloading to the servers across the access layer switches.

The aggregation layer switches carry the workloads of spanning-tree processing and default gateway redundancy protocol processing. The aggregation layer might be the most critical layer in the data center because port density, oversubscription values, CPU processing and service modules introduce unique implications into the overall design.