Dynamics of hot-potato routing in IP networks

  • Authors:
  • Renata Teixeira;Aman Shaikh;Tim Griffin;Jennifer Rexford

  • Affiliations:
  • UC San Diego, La Jolla, CA;AT&T Labs--Research, Florham Park, NJ;Intel Research, Cambridge, UK;AT&T Labs--Research, Florham Park, NJ

  • Venue:
  • Proceedings of the joint international conference on Measurement and modeling of computer systems
  • Year:
  • 2004

Quantified Score

Hi-index 0.00

Visualization

Abstract

Despite the architectural separation between intradomain and interdomain routing in the Internet, intradomain protocols do influence the path-selection process in the Border Gateway Protocol (BGP). When choosing between multiple equally-good BGP routes, a router selects the one with the closest egress point, based on the intradomain path cost. Under such hot-potato routing, an intradomain event can trigger BGP routing changes. To characterize the influence of hot-potato routing, we conduct controlled experiments with a commercial router. Then, we propose a technique for associating BGP routing changes with events visible in the intradomain protocol, and apply our algorithm to AT&T's backbone network. We show that (i) hot-potato routing can be a significant source of BGP updates, (ii) BGP updates can lag 60 seconds or more behind the intradomain event, (iii) the number of BGP path changes triggered by hot-potato routing has a nearly uniform distribution across destination prefixes, and (iv) the fraction of BGP messages triggered by intradomain changes varies significantly across time and router locations. We show that hot-potato routing changes lead to longer delays in forwarding-plane convergence, shifts in the flow of traffic to neighboring domains, extra externally-visible BGP update messages, and inaccuracies in Internet performance measurements.