An Adaptive Mechanism to Solve BGP Divergence Resulted from Policies Conflict

Abstract

BGP(border gateway protocol)作为一种基于策略的协议,允许每个自治系统独立地选择本地路由策略.自治系统之间可能存在的路由策略冲突会引起BGP路由持续不稳定.当前提出的解决办法要么需要增加额外的通信开销,要么限制自治系统自由的选择路由策略.提出了一种解决策略冲突引起BGP路由不收敛的自适应方法,既不损害自治系统选择路由策略的灵活性,也不需要在BGP消息中增加额外信息.路由的稳定性被加入到BGP的判决过程中,不稳定路由的优先级被降低,使更加稳定的路由得以被选为最优路由,终止路由策略冲突引起的争执.在网络拓扑发生改变的情况下,这种新方法能够自适应地调整路由选择,重新收敛到新的稳定状态.;As a policy-based routing protocol, BGP (border gateway protocol) allows each AS to choose local routing policy independently. Possible policies conflict may result in BGP route persistent oscillation. This paper proposes an adaptive mechanism to guarantee BGP convergence with policies conflict, which neither impairs the flexibility of choosing routing policy, nor inserts additional information in BGP messages. With the mechanism, route stability is taken into BGP decision process so that unstable route is degraded to cause more stable route to be chosen to stop policies dispute. The new mechanism also can adapt to topology change and converge to new stable route.