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Re: [RRG] Geoff Huston's article on BGP stability, update statistics and damping



Geoff,

  "10% of announced prefixes being responsible for 53% of all
   routing updates, and the busiest 1% of prefixes responsible
   for 24% of the routing updates for the month."

  "It can’t be the case that more than a million routing updates
   actually reflect true underlying changes in topology of the
   network, given that these one million updates only refer to
   2,000 prefixes."

I think the time analysis of the updates would be of interest to
anyone concerned about BGP stability.

I would hope so. A significant proportion of the BGP traffic appears to
be concerned with a relatively small number of "pathologies" where BGP
itself is the amplifier.

I think that when looking at the BGP prefixes that are responsible for
most of the churn, it is worth mentionning that some studies have looked
at traffic traces in parallel with BGP update traces and have shown
clearly that the BGP prefixes with lots of instabilities are usually
prefixes that do not carry large amount of packets.

See e.g.

S. Uhlig, V. Magnin, O. Bonaventure, C. Rapier and L. Deri
Implications of the topological properties of Internet traffic on
traffic engineering, 19th ACM Symposium on Applied Computing, Special
Track on Computer Networks, March 2004.
http://inl.info.ucl.ac.be/publications/implications-topological-properties-internet-traffic-traffic-engineering

Jennifer Rexford, Jia Wang, Zhen Xiao, and Yin Zhang, "BGP routing
stability of popular destinations," Proc. Internet Measurement Workshop,
November 2002



Olivier


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