Re: [rrg] Geoff Huston's BGP/DFZ research - 300k DFZ prefixes are the tip of the iceberg

[Lixia Zhang <[e-mail]>]

On Mar 14, 2010, at 1:33 PM, Amund Kvalbein wrote:

> Folks,
>
> In this context, I think you might be interested in a measurement  
> study that will be presented at INFOCOM this coming week. The focus  
> of the study is BGP scalability with respect to churn rates. We have  
> analyzed six years of Routeviews BGP update traces from four  
> monitors in different tier-1 networks.
>
> Some of the main findings are that
> - BGP churn varies widely on many time scales, and cannot be  
> understood through "black-box" statistical analysis.
> - The most severe churn experienced by these monitors are caused by  
> mis-configurations and events that are local to the monitored AS.
> - Surprisingly, as much as 40% of churn consists of duplicate  
> announcements, which are unnecessary for correct protocol operation.  
> This figure has been pretty constant over our measurement period.

we did a measurement study to understand the causes of such excessive  
duplicate announcements, the results are reported in the following  
paper:
"Investigating Occurrence of Duplicate Updates in BGP Announcements"
http://www.cs.ucla.edu/~jpark/dupbgp.pdf
to be presented at PAM conference next month

An earlier presentation can be found at
    http://www.cs.ucla.edu/~jpark/grow-5.pdf

> - After filtering out duplicates, local effects and anomalies caused  
> by a few specific events, we find that there is an increasing trend  
> in "baseline" churn over the past six years, but that this growth is  
> quite modest, and much slower than the growth in the DFZ RIB size.
>
> The paper can be found at
> http://simula.no/research/nd/publications/Simula.nd.435
> Comments are always welcome.
>
> Regards,
> Amund