Enterprise Data Center Network Design

Data center design is similar to the enterprise campus with a few exceptions, such as a few features and product and performance differences. Other than those, routing is routing and switching is switching. The data center multilayered architecture consists of the following layers:

• Aggregation layer: The aggregation layer is the termination point for the access layer and connects the data center network to the enterprise core. In many designs, enterprises consider the core to be also part of the data center, but the design principles still remain the same for the core layer. In the data center, the aggregation layer also serves as a services layer, offering Layer 4 to Layer 7 services including security (firewall), server load balancing (SLB), and monitoring services.

• Access layer: The access layer can be a physical access layer using Catalyst and Nexus switches, or it can be virtual access layer by using a hypervisor-based software switch such as the Cisco Nexus 1000v. The access layer connects virtual machines and bare-metal servers to the network. The access layer typically connects to the servers using 10/100/1000 connectivity with uplinks to the distribution at 10 G speeds.