Information Technology Reference
In-Depth Information
C
H
A
P
T
E
R
8
Route Reflection and
Confederation Migration
Strategies
This chapter covers the following migration strategies that are relevant to iBGP scalability:
•
From iBGP full mesh to route reflection
•
From iBGP full mesh to confederation
•
From route reflection to confederation
•
From confederation to route reflection
The subject of route reflection and confederation was discussed in Chapter 7, “Scalable
iBGP Design and Implementation Guidelines.” As networks expand, the need to migrate
from one architecture to another arises to increase iBGP scalability. The focus of this chap-
ter is the deployment of these migration techniques. Four case studies are provided in this
chapter to demonstrate in detail how to migrate one architecture to another. Note that these
procedures document only one of the ways to complete the migration. There are probably
many ways to do this. Where appropriate, different migration methods are compared and
contrasted. The procedures are written with the goal of minimizing network downtime and
traffic loss.
General Migration Strategies
This section discusses the general migration strategies that apply to all four case studies
in this chapter. To ensure a successful migration, you must take certain preparatory steps
before the migration. Some common concerns of migrations are discussed in this section
as well.
Preparatory Steps
Before you start the migration, certain preparatory steps are needed. The following are
some of the points to consider:
•
Verify that all loopback addresses, when used as peer addresses, are still reachable
via IGP.
•
Ensure that remote console access is available on all the routers in the AS.
