Hello jaishankar,
you can start from the following link in the BGP case studies
https://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/26634-bgp-toc.html#routereflectors
Route reflector can solve the full mesh requirement of iBGP by allowing controlled reflection / propagation of routes originated by clients
Edit:
Route Reflectors allow for safe reflection of routes within an AS by adding two optional attributes to each prefix:
Originator Id : BGP Router-id of the router that injected the prefix in the domain
Cluster List: it is an ordered list of reflections via multiple RRS clusters each RRS puts the cluster-id if configured or its own BGP router-id.
The first attribute allows a router to discard a route that it has originated
The second attribute tracks the history of propagation of the BGP advertisement in the AS.
The shortest Cluster list is preferred when choicing the best path.
The Cluster List also provides for loop avoindance if the RRS receives an advertisement that already includes in the cluster list its own cluster-id (manually set or its BGP router-id) it can ignore it.
RRS have an impact in best path choice: they propagate only the best path for a prefix.
Some new features allows to propagate also additional backup paths but they may be not supported on all platforms.
Hope to help
Giuseppe
