Optimizing IBGP route reflection network

Abstract

In the conventional internal border gateway protocol (IBGO), the BGP sessions between all BGP speakers in a single autonomous system (AS) form a full mesh. For scalability reasons, route reflection is proposed as an alternative to the full mesh inside an AS. The selection of route reflectors and their clients determines the path used by IGBP route advertising. Thus, the design of the route reflection graph is an important issue for improving IBGP operating efficiency and reliability. This paper focuses on the topology optimization for the route reflection graph, i.e., the selection of the reflectors and the interconnections between reflectors and clients. We propose the optimum reflection graph (ORG) problem to find the best topology for IBGP reflection according to the efficiency or reliability metrics. We give the solvability conditions for the problem and present solution based on the integer programming model. Our approach is also highly flexible. Human decisions or constraints can be easily incorporated to find a topology which satisfies AS administrator's manual configurations.