I seem to remember there were some good old (really old now) books on BGP discussing various design aspects of BGP infrastructure including topology-based or address-based route reflection, etc...

Topology-based doesn’t need to mean in-path you can still have a whole fleet of out-of-the-path RRs servicing say south-east region.  

My advice is:

-Keep your RR-1 infra separate form RR-2 infra (when RR1&RR2=same cluster).

-Keep your Internet-RRs and Services-RRs infrastructures separate (ships in night), which is very easy to pull off with current virtualized RRs.

-Type-1 RDs will help you simulate full-mesh.  

adam

From: NANOG <nanog-bounces@nanog.org> On Behalf Of Mohammad Khalil
Sent: Sunday, February 10, 2019 8:10 PM
To: nanog@nanog.org
Subject: BGP topological vs centralized route reflector

Dears

Am trying to find some documents and practical implementations regarding bgp topological vs centralized route reflector(In-band vs out-of-band)

Any good shares are appreciated