Home page logo
/

nanog logo nanog mailing list archives

Re: Points of Failure (was Re: National infrastructure asset)
From: Peter van Dijk <peter () dataloss nl>
Date: Tue, 25 Sep 2001 22:20:13 +0200


On Tue, Sep 25, 2001 at 04:04:38PM -0400, batz wrote:
[snip]
Is there a geometric method of measuring the 'meshedness' of a 
given set? If you take all the as-paths from a sampling of 
peers across the Internet, and show the relative density of 
where the respective paths converge, you can get a good picture
of who's transiting the most routes. 

The mathematical term 'connectivity' measures the least number of
vertices that has to be destroyed to stop a network from being fully
connected.

Any network that contains a SPoF (even if it only causes one small bit
to go lost) has a connectivity of '1'. Any network that you need to
hit at least 2 vertices (routers and switches would be vertices, lines
would be edges) has a connectivity of '2'.

There are very nice mathematical methods for determining the
connectivity and connectionness of a graph (network).

I can recommend Skiena's "The algorithm design manual" for anybody
interested. It is supposedly available online in HTML (I bought the
dead tree version :)

Greetz, Peter
-- 
Monopoly        http://www.dataloss.nl/monopoly.html


  By Date           By Thread  

Current thread:
[ Nmap | Sec Tools | Mailing Lists | Site News | About/Contact | Advertising | Privacy ]