On Wed, 7 Jun 2006, Bruno Quoitin wrote:
Matthew Petach wrote:
Q: Randy Bush. Common problem we all face. I'm at 42 peering points; my neighbors are X. I have route views dumps, I have my BGP dumps. I have my netflow data. Want a whatifatron that shows what happens to my traffic if depeer someone, or add someone, or peer with SingTel in singapore, or stop peering with Joe in SF. That's a question many operators ask every day.
We have such a whatifatron. We used it for instance to investigate the impact of peering/depeering on routing and on traffic in various ISP networks including a large european transit network. Our tool is called C-BGP and some of the what-if scenarios we performed on the GEANT network were described recently in an IEEE Network paper entitled "Modeling the routing of an Autonomous System with C-BGP" (November 2005).
Additionally, Richard Steenbergen has this: http://www.nanog.org/mtg-0510/steenbergen.html to say about this subject, the talk seemed cool, the tool is on sourceForge I believe...