Design Guide
Figure 7.
Data Center Front-End Network
Aggregation Layer
The aggregation layer is a point of convergence for network traffic that provides connectivity
between server farms and the rest of the enterprise. The aggregation layer supports Layer 2 and
Layer 3 functions and presents an ideal location for deploying centralized application, security, and
management services. Shared across the access layer server farms, these data center services
provide an efficient, scalable, predictable, and deterministic behavior common to server-farm
needs.
The aggregation layer provides a comprehensive set of features for the data center. The following
devices support these features:
●
Multilayer aggregation switches
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Load-balancing devices
●
Firewalls
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IDSs
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Content engines
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Secure Sockets Layer (SSL) offloaders
●
Network-analysis devices
Access Layer
The primary role of the access layer is to provide the server farms with port density. In addition, it
must be a flexible, efficient, and predictable environment supporting client-to-server and server-to-
server traffic. A Layer 2 domain meets these requirements by providing the following:
●
Adjacency between servers and service devices
●
A deterministic, fast-converging, loop-free topology
© 2008 Cisco Systems, Inc. All rights reserved. This document is Cisco Public Information.
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