Quite a few researchers have looked at the topology of AS interconnection. They have found that AS connectivity follows a power law - i.e. the vast majority have a few connections while a small minority has the majority of connections. Same as an earthquake - most are small and not noticable but a few are huge, smash a boulder and you get the same thing. Lots of dynamic networks follow this topology. The upside is that they are incredibly robust to random failures but very susceptible to targeted failures. For details see: http://www.physicsweb.org/article/world/14/7/09 ----- Original Message ----- From: Jared Mauch <jared@puck.Nether.net> Date: Friday, September 6, 2002 2:20 pm Subject: Re: Vulnerbilities of Interconnection

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On Fri, 6 Sep 2002, Pawlukiewicz Jane wrote: :would be difficult to reach. I'd have to run a model to be sure, but :every one of the major seven have rerouting methodologies that would> :recover from the loss. And I don't think they exclusively

On Fri, Sep 06, 2002 at 01:55:40PM -0400, batz wrote: peer at

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ASN's to "fail", then see who is still connected, but we are still dealing with connectivity relatve to us and our peers, even 5+ AS-hops away.

I would imagine this is one of the tasks CAIDA.org is probably working on, as it seems to fall within their mission.

Coming up with the as interconnection data is actaully fairly easy if you parse route-views data. This obviously doesn't cover every possible interconnection that exists but it does provide a large swath of data to review for the interconnection postulation.

Looking at that data, (this is an old snapshot) the top ten networks are: (in #10->#1 order)

conn ASN ----+---- 161 3356 229 1 242 2914 248 209 274 6461 277 3561 295 3549 328 7018 484 701 493 1239

- Jared

-- Jared Mauch | pgp key available via finger from

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clue++; | http://puck.nether.net/~jared/ My statements are only mine.