Stable IBGP Route Research Based On Minimal Hops

In the Internet, domain routing system use Border Gateway Protocol to distribute routing reachability information in different AS (autonomous system). As the internal part of BGP, Internal BGP propagates the reachability routing information of different AS within an AS. So the stability of domain routing system can impact on the end-to-end performance directly.Research shows there is not only routing instability between border routers in different ASes, but iBGP route oscillation between routers in an AS because of the use of route reflection and Multi-Exit-Discriminator property. Besides, the timing co-incidence of route announcement also affects routing stability. Therefore, researching how to avoid route oscillation emerged in AS when domain routing information is propagated is an important issue to shorten BGP convergence time and enhance internetwork performance. On the basis of analyzing BGP routing decision process, this paper analysis the process of best routing selection based on minimal iBGP hop pointed out by Flavel et al. making use of routing algebra, and proof by contradiction that it has the property of strict monotonic.Because the strict monotonic of routing algebra can guarantee the convergence of path-vector routing protocol, we further obtain that iBGP routing based on the minimal hop convergence to stable status. Besides, based on the platform simBGP, the we conduct that simulation experiments in three classical topologies using the method based on the minimal hops iBGP routing decision, obtain the precise experimental result, compare and analyses the convergence results with the original oscillation results. Experimental results show that this method which based on minimal hop can cut off the relativity of linear relativity between network elements, achieve the goal of convergence, and ensure the routing stability when domain route information is propagate.