This document defines the BGP Monitoring Protocol (BMP), which can be used to monitor BGP sessions. BMP is intended to provide a convenient interface for obtaining route views. Prior to the introduction of BMP, screen scraping was the most commonly used approach to obtaining such views. The design goals are to keep BMP simple, useful, easily implemented, and minimally service affecting. BMP is not suitable for use as a routing protocol.
Currently in the Internet, BGP deployments are configured such that all BGP speakers within a single AS must be fully meshed and any external routing information must be re-distributed to all other routers within that AS. For n BGP speakers within an AS that requires to maintain n*(n-1)/2 unique IBGP sessions. This "full mesh" requirement clearly does not scale when there are a large number of IBGP speakers each exchanging a large volume of routing information, as is common in many of todays internet networks.
This scaling problem has been well documented and a number of proposals have been made to alleviate this [2,3]. This document represents another alternative in alleviating the need for a "full mesh" and is known as "Route Reflection". This approach allows a BGP speaker (known as "Route Reflector") to advertise IBGP learned routes to certain IBGP peers. It represents a change in the commonly understood concept of IBGP, and the addition of two new optional transitive BGP attributes to prevent loops in routing updates.