nx.os.and.cisco.nexus.switching.2nd.edition.1587143046

Chapter 14. Nexus Migration Case Study
The case study in this chapter demonstrates a migration from a traditional Catalyst-based
data center infrastructure to a next-generation Nexus-based data center. This case study
brings together a great deal of the topics discussed individually throughout this book and
combines them with work performed by the authors in Cisco engineering labs and multiple
real-world customer scenarios, including their requirements, designs, and deployments. This
case study can provide a foundation for organizations looking to make a similar migration.
Existing Environment
Acme, Inc., is a large global enterprise with many diverse lines of business. Its information
technology group is a centralized group that provides technology services to all lines of
business. Acme, Inc., has been a long-time Cisco customer with a great track record of
success with the Catalyst 6500 switching family. Acme, Inc., has chosen to use the industryleading
practice of a three-tier design.
The server access is spread between six pairs of Catalyst 6509 switches. Each pair of
6509s serves a specific area (region) of the data center and is distributed throughout the data
center accordingly. Each region of the data center contains a defined set of approximately
four to five virtual local area networks (VLANs) dedicated to specific server types and
functions, that is, a VLAN for UNIX, a VLAN for Windows, and so on. Each pair of 6509s
provides redundancy for the servers’ default gateway by using Hot-Standby Router Protocol
(HSRP).
To optimize traffic flows for server-to-server communication within the data center, an L3
server distribution layer has been introduced. The primary role of this layer is to
interconnect each of the six access pairs and provide network connectivity to the core layer.
All connectivity to this layer is achieved using routed point-to-point links.
The core layer provides connectivity to the campus network and connects to various WAN
routers for remote office connectivity. This layer is completely Layer 3 routed using EIGRP
as the IGP. All connectivity into this layer is done with routed point-to-point links.
Figure 14-1 shows the existing environment.