Information Technology Reference
In-Depth Information
The following is a high-level summary of the steps involved:
Select the starting core router, R4.
Step 1
Create a new peer group for clients, and enable route reflection.
Step 2
Move all access routers to the new peer group created for clients.
Step 3
Move the other core router, R5, to RR, and add access routers as clients.
Repeat Steps 2 and 3 for R5.
Step 4
Remove iBGP sessions that are no longer needed.
Step 5
Repeat Steps 1 through 5 for the other POP.
Step 6
Verify BGP reachability for all prefixes.
Step 7
These steps are presented in such a way for easier discussion. In real migration, many of
the steps might be completed simultaneously in one maintenance window.
NOTE
The following sections illustrate the detailed procedures.
Step 1: Select the Starting Core Router
Step 1
Start the migration from a core router that will be an RR. R4 is selected.
Step 2: Create a New Peer Group for Clients, and Enable Route Reflection
On R4, create another peer group called Clients to represent all its clients. Example 8-13
shows a sample peer group configuration.
Example 8-13
Peer Group for Clients
neighbor Clients peer-group
neighbor Clients remote-as 100
neighbor Clients update-source Loopback0
neighbor Clients route-reflector-client
Step 3: Move All Access Routers to the New Peer Group
Move client peerings on R4 from the existing Internal peer group to the Clients peer group.
Within the POP on the right, move R6 and R7, one at a time, from the Internal peer group
to the Clients peer group. No configuration changes are needed on the clients.
