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Some Observations on Network Failures NANOG 15

Some Observations on Network Failures NANOG 15. Craig Labovitz <labovit@merit.edu>. Observations. Goal : Model Internet topological changes Lots of strange BGP routing Strange BGP routing went away What causes remaining BGP topological and policy changes?

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Some Observations on Network Failures NANOG 15

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  1. Some Observations on Network FailuresNANOG 15 Craig Labovitz <labovit@merit.edu>

  2. Observations • Goal: Model Internet topological changes • Lots of strange BGP routing • Strange BGP routing went away • What causes remaining BGP topological and policy changes? • Not just count flaps, but study how routing tables changes over extended periods • Not end-to-end

  3. Internet Failures Analysis • Look at default-free BGP announcements from multiple large providers • Long lived (60 % of 9 months) • Consider stable if covered by less specifics • 15 minute filter window • Mean-time failure, repair and availability • Case study regional network

  4. What We Did • Lots of probe machines • Mae-East, Mae-West, Paix, PacBell, AADs • A default-free collector at UM • Routeviews Multi-hop EBGP 6 providers US, Canada, Europe and Japan (300,000 routes) • Case study of regional backbone (OSPF, IBGP/BGP) • 42 gigabytes and four years of logged routing packets

  5. RouteTracker • Peer with ISP routers • Log all routing packets to disk • Maintain statistics

  6. MTBF

  7. Route Fail-Over

  8. MTTR

  9. Availability

  10. Default-Free Route Availability

  11. Backbone MTR

  12. Network Failures Michnet Backbone Failures 11/97 - 11/98

  13. Observations • Internet significantly less availability than PSTN (99.99% +) • Low mean time to change

  14. Next Steps • Host other routeviews machines? • Merit has several FreeBSD desktop boxes • Looking for peers… • ipma-support@merit.edu

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