Network integrity and non-random removal of nodes

sgorman1 at sgorman1 at
Thu Nov 21 19:00:03 UTC 2002

It still depends on the network that you are using for analysis. 
Assuming the paper uses the same dataset as the link Sean provided the
giant cluster they are analyzing is only 8.3% of IP nodes in their
sample. It takes the removal of 25% when only looking at that small
densely connected section, it says nothing about what will happen to the
other 91.7% of nodes.  Considering that 55% of the remaining nodes are
trees, they will be saying "Houston we have a problem" well before 25%.
 Whether or not it matters that they have a problem in an entirely
different question.  I've probably kicked this dead horse enough already

----- Original Message -----
From: William Waites <ww at>
Date: Thursday, November 21, 2002 6:31 pm
Subject: Re: Network integrity and non-random removal of nodes

> >>> "Sean" == Sean Donelan <sean at> writes:
>    Sean> On 20 Nov 2002, William Waites wrote:
>    >> If you  randomly select nodes to  remove, by the  time you have
>    >> removed 25% of  them, the network breaks up  into many isolated
>    >> islands.
>    Sean> One of the  key points was the nodes  were removed in ranked
>    Sean> order, not in random order.
> I stand corrected. 
> It would be interesting to see what outdegree looks like as a function
> of  rank --  in  the paper  they  give only  the  maximum and  average
> (geo. mean) outdegrees. Is there also  a critical point 25% of the way
> through  the ranking?  Probably not  or one  would expect  they'd have
> mentioned it...
> So then  the 12500  *biggest* routers have  to be disabled  before the
> graph  breaks into  many islands.  This would  be yet  harder  
> from an
> attacker's point of view, no?
> -w

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