In BGP, imagine if you need to setup redundancy on BGP speakers:
Which mechanism offers better performance: full-mesh, confederations or router reflectors?
full mesh is simply not scalable
for N routers it requires to setup N*(N-1)/2 iBGP sessions.
if N=100 it would mean 4950 that is not possible on a single device !
BGP Route Reflector servers are the most used solution to overcome full mesh limitations.
to be noted that BGP confederations and Route Reflector servers can be combined used together in very big service providers networks.
in big environments the performance challenges are moved to the devices acting as route reflector servers
different strategies can be used to get even better scalability:
multiple levels of Reflection
using different groups of route reflector servers with different objectives: like RRS for internet routes, others for internal routes, others for MPLS VPNv4 routes (eventually partitioned)
Hope to help
Messaggio modificato da giuslar