CleanBGP: Verifying the consistency of BGP data

Copyright © 2008 IEEEBGP data contains artifacts introduced by the measurement infrastructure which can substantially affect analysis. This is especially important in operational systems where "crying wolf" will result in an operator ignoring alarms. In this paper, we investigate the causes of measurement artifacts in BGP data - cross-checking and using properties of the data to infer the presence of an artifact and minimize its impact. We have developed a prototype tool, CleanBGP, which detects and corrects the effects of artifacts in BGP data, which we believe should be used prior to the analysis of such data. CleanBGP provides the user with an understanding of the artifacts present, a mechanism to remove their effects, and consequently the limitations of results can be fully quantified.Ashley Flavel, Olaf Maennely, Belinda Chiera, Matthew Roughan and Nigel Bea

SWIFT: Predictive Fast Reroute

Network operators often face the problem of remote outages in transit networks leading to significant (sometimes on the order of minutes) downtimes. The issue is that BGP, the Internet routing protocol, often converges slowly upon such outages, as large bursts of messages have to be processed and propagated router by router. In this paper, we present SWIFT, a fast-reroute framework which enables routers to restore connectivity in few seconds upon remote outages. SWIFT is based on two novel techniques. First, SWIFT deals with slow outage notification by predicting the overall extent of a remote failure out of few control-plane (BGP) messages. The key insight is that significant inference speed can be gained at the price of some accuracy. Second, SWIFT introduces a new data-plane encoding scheme, which enables quick and flexible update of the affected forwarding entries. SWIFT is deployable on existing devices, without modifying BGP. We present a complete implementation of SWIFT and demonstrate that it is both fast and accurate. In our experiments with real BGP traces, SWIFT predicts the extent of a remote outage in few seconds with an accuracy of ~90% and can restore connectivity for 99% of the affected destinations

Realistic BGP Traffic for Test Labs

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.Olaf Maennel and Anja Feldman