Tài liệu MPLS VPN Migration Strategies pptx

5
MPLS VPN Migration
Strategies
5-2 MPLS VPN Migration Strategies Copyright  2000, Cisco Systems, Inc.
Infrastructure Migration
Review Questions
n How can you minimize the effect of core migration to MPLS for regular IP
traffic?
Use conditional label advertising.
n Can you allocate labels only to PE loopback addresses if you are using an
ATM core?
Yes, with conditional label advertising.
n What are the benefits of edge-first migration toward MPLS infrastructure?
It is easier and quicker to implement.
It enables clear separation of migration issues.
It does not involve any IP reconfiguration of core devices in the network.
n What are the drawbacks of edge-first migration toward MPLS infrastructure?
When implemented with the GRE tunnels it suffers from encapsulation
overhead.
It has severe scalability constraints.
It requires point-to-point links between islands of MPLS connectivity.
n Which migration strategy is better suited for early MPLS VPN pilots?
The Migration from Edge strategy.
n Which migration strategy is better for a large-scale MPLS VPN rollout?
The Migration from Core strategy.
Copyright  2000, Cisco Systems, Inc. Release Date: October 2000 5-3
Customer Migration to MPLS VPN service
Review Questions
n What are the steps in overlay VPN customer migration toward MPLS VPN?
Remove the link to the overlay VPN after the last site has been
migrated.

Select one site to act as a central transit site during migration process.
Migrate other sites step by step. Let the IGP take care of the changes in
the VPN.
Connect the central site through a new virtual circuit or physical
interface to the MPLS/VPN backbone and deploy the target PE-CE
routing protocol.
n What are the necessary steps in layer-3 VPN customer migration toward
MPLS VPN?
Announce the tunnel endpoints into the MPLS/VPN backbone.
Select a site (or a few sites) to act as a transit point between the old and
the new VPN backbone.
For every other site, establish connectivity with the new VPN backbone,
test routing information exchange and then disable connectivity (GRE
tunnels)with the old backbone.
When Frame Relay is used only in transition, revert to original
encapsulation on the transit site, and put the interface into the new VRF.
Connect the transit site to the new MPLS/VPN backbone via a
dedicated link (or Frame Relay subinterface) and start PE-CE routing
protocol.
n Which protocol should you use as the PE-CE routing protocol when migrating
customers are using EIGRP as their VPN routing protocol?
BGP