Data Center LAN Migration Guide - Juniper Networks

Data Center LAN Migration Guide
At the level of the data center network core and the transparent virtual WAN that an organization can use to support
its business continuity and workload mobility goals, MPLS provides a number of key advantages over any other
alternative:
• MPLS virtualization enables the physical network to be run as many separate virtual networks. The benefits include
cost savings, improved privacy through traffic segmentation, improved end user experience with traffic engineering
and QoS, and improved resiliency with functionality such as MPLS fast reroute and BFD. This can be done in a
completely private network context (e.g., the enterprise owns the entire infrastructure), or it can be achieved through
the interworking of the organization’s private data center and WAN infrastructures with an appropriately deployed
carrier service.
• VPLS provides Ethernet-based point-to-point, point-to-multipoint, and multipoint-to-multipoint (full mesh)
transparent LAN services over an IP/MPLS infrastructure. It allows geographically dispersed LANs to connect across
an MPLS backbone, allowing connected nodes (such as servers) to interpret that they are on the same Ethernet LAN.
VPLS thus provides an efficient and cost-effective method for communicating at L2 across two or more data center
sites. This can be useful for transaction mirroring in active/active or other backup configurations. And it is necessary
for supporting workload mobility and migration of virtual machines between locations over a WAN.
• MPLS can provide private L3VPN networks between data center sites that share the same L3 infrastructure. A
composite, virtualized L2 and L3 infrastructure can thus be realized. Very useful security properties can be achieved
in such a design as well. For example, by mapping L3VPNs to virtual security zones in an advanced firewall such as
the SRX Series, many security policies can be selectively layered on the traffic.
Also in support of business continuity, MPLS’ traffic engineering (TE) and fast reroute capabilities combine
sophisticated QoS and resiliency features into a multiservice packet core for superior performance and economics.
TE could be used to support real-time data replication and transaction mirroring, along with service-level agreement
(SLA) protection for real-time communications such as video conferencing and collaboration services. Fast reroute
delivers rapid path protection in the packet-based network without requiring redundant investments in SONET or SDH
level services (e.g., superior performance for lower cost).
For workload mobility that involves extending a Layer 2 domain across data centers to support relevant applications
like VMware VMotion, archiving, backup, and mirroring, L2VPNs using VPLS could be used between data center(s).
VPLS allows the connected data centers to be in the same L2 domain, while maintaining the bandwidth required for
backup purposes. This feature ensures that other production applications are not overburdened.
Best Practices for Incorporating MPLS/VPLS in the Data Center Network Design
Current L2/L3 switching technologies designed for the LAN do not scale well with the appropriate levels of rerouting,
availability, security, QoS, and multicast capabilities to achieve the required performance and availability. As a result,
when redesigning or upgrading the data center, an upgrade to MPLS is frequently appropriate and justified to meet
business operational demands and cost constraints. MPLS often simplifies the network for the data center, removing
costly network equipment and potential failure points while providing complete network redundancy and fast rerouting.
When fine grained QoS is required with traffic engineering for the data center, RSVP should be used to establish
bandwidth reservations based upon priorities, available bandwidth, and server performance capacities. MPLS-based
TE is a tool made available to the data center network administrators which is not presently available in common
IP networks. Furthermore, MPLS virtualization capabilities can be leveraged to segment and secure server access,
becoming a very important part of maintaining a secure data center environment.
For this section of the Data Center LAN Migration Guide, the prior construct of best practice, preinstall, install, and post
install is going to be combined into six process steps for migrating to MPLS, keeping in mind that VPLS runs over an IP/
MPLS network.
Copyright © 2012, Juniper Networks, Inc. 49