Realistic BGP Traffic for Test Labs

Abstract

This paper examines the possibility of generating realistic routing tables of arbitrary size along with realistic BGP updates of arbitrary frequencies via an automated tool deployable in a small-scale test lab. Such a tool provides the necessary foundations to study such questions as: the limits of BGP scalability, the reasons behind routing instability, and the extent to which routing instability influences the forwarding performance of a router.We find that the answer is affirmative. In this paper we identify important characteristics/metrics of routing tables and updates which provide the foundation of the proposed BGP workload model. Based on the insights of an extensive characterization of BGP traffic according to such metrics as prefix length distributions, fanout, amount of nesting of routing table prefixes, AS path length, number and times between BGP update bursts and number and times between BGP session resets, etc., we introduce our prototype tool, rtg. rtg realizes the workload model and is capable of generating realistic BGP traffic. Through its flexibility and parameterization rtg enables us to study the sensibilities of test systems in a repeatable and consistent manner while still providing the possibility of capturing the different characteristics from different vantage points in the network.