An Adaptive Mechanism to Guarantee BGP Routing Convergence with Policies Conflict

As a policy-based routing protocol, BGP allows each autonomous system choose routing policy locally. Possible policies conflict may result in BGP route oscillating persistently. Current solutions either require additional communication overhead, or limit choosing routing policy freely. In this paper, we propose an adaptive mechanism to guarantee BGP convergence with policy conflict, which neither impairs the flexibility of choosing routing policy, nor inserts additional information in BGP messages. Route stability is taken into BGP decision process, unstable route is degraded to cause more stable route to be chosen and stop policy dispute. The new mechanism make BGP routing adapt to topology change and converge to new stable route.