migrate full mesh IBGP to route reflector ibgp network

[fly]

Dear Sir/Madam,
  we want to migrate current customer's full mesh ibgp network to route reflector architecture

but customer network is a product network , we can't take down the network ,there is some questions

1 when i config one core router as RR, and point to client. when i modify config will client lose neighor or routes,
can clients get route from another full mesh neighor
2 when i config another core route as RR, same questions as above

  thank you!
tom

[chrihussey]

If I understand your question correctly, when you define the route reflector client on the core, the client will not automatically lose all its other IBGP neighbors and routes.

What you will need to do is define the client on the core and shut all other the other IBGP sessions on the client. You may have to clear the session between the core and the client too. There will be a period of reconvergence, but if done correctly it shouldn't take long. Then adding the second core as a RR should be a non event.