Data Center LAN Migration Guide - Juniper Networks

Data Center LAN Migration Guide
Introduction to the Migration Guide
IT has become integral to business success in virtually all industries and markets. Today’s data center is the centralized
repository of computing resources enabling enterprises to meet their business objectives. Today’s data center traffic
flows and performance requirements have changed considerably from the past with the advent of cloud computing
and service-oriented architecture (SOA)-based applications. In addition, increased mobility, unified communications,
compliance requirements, virtualization, the sheer number of connecting devices, and changing network security
boundaries present new challenges to today’s data center managers. Architecting data centers based on old traffic
patterns and outdated security models is inefficient and results in lower performance, unnecessary complexity,
difficulty in scaling, and higher cost.
A simplified, cloud-ready, two-tier data center design is needed to meet these new challenges—without any
compromise in performance. Migrating to such a data center network can theoretically take place at any time.
Practically speaking, however, most enterprises will not disrupt a production data center except for a limited time
window to perform scheduled maintenance and business continuity testing. Luckily and within this context, migration
to a simpler two-tier design can begin at various insertion points and proceed in controlled ways in an existing legacy
data center architecture.
Juniper’s Data Center LAN Migration Guide identifies the most common trigger events at which migration to a
simplified design can take place together with design considerations at each network layer for a successful migration.
The guide is segmented into two parts. For the business decision maker, Chapter 1: Why Migrate to Juniper will be most
relevant. The technical decision maker will find Chapters 2 and 3 most relevant, particularly Chapter 3, which covers
the data center “trigger events” that can stimulate a transition and the corresponding insertion points, designs, and
best practices associated with pre-install, install, and post-install tasks.
Audience
While much of the high-level information presented in this document will be useful to anyone making strategic
decisions about a data center LAN, this guide is targeted primarily to:
• Data center network and security architects evaluating the feasibility of new approaches in network design
• Data center network planners, engineers, and operators designing and implementing new data center networks
• Data center managers, IT managers, network and security managers planning and evaluating data center
infrastructure and security requirements
Data Center Architecture and Guide Overview
One of the primary ways to increase data center efficiency is to simplify the infrastructure. Most data center networks
in place today are based on a three-tier architecture. A simplified two–tier design, made possible by the enhanced
performance and more efficient packaging of today’s Ethernet switches, reduces cost and complexity, and increases
efficiency without compromising performance.
During the 1990s, Ethernet switches became the basic building block of enterprise campus network design. Networks
were typically built in a three-tier hierarchical tree structure to compensate for switch performance limitations. Each
tier performed a different function and exhibited different form factors, port densities, and throughputs to handle the
workload. The same topology was deployed when Ethernet moved into the data center displacing Systems Network
Architecture (SNA), DECnet, and token ring designs.
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