BGPSep_S: An Algorithm for Constructing IBGP Configurations with Complete Visibility

IBGP configurations based on the route reflection may violate the properties of complete visibility, thus leading to forwarding loops and sub-optimal paths. On the other hand, a router should not maintain too much BGP sessions because of performance reason. This paper presents an IBGP topology construction algorithm, called BGPSep_S, by taking into consideration the vertexes degrees, the vertexes separators and the shortest paths between vertexes in the underlying IGP graph. We prove that BGPSep_S guarantees complete visibility in normal situations. And the performance of BGPSep_S is evaluated on several real-world backbone topologies. Experimental results show that the maximum degrees of the IBGP topologies generated by BGPSep_S for these IGP topologies can be reduced by about 27%-68%, compared with full mesh and BGPSep.