North American Network Operators Group
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Re: Yahoo outage summary

  • From: Sean Donelan
  • Date: Sun Jul 08 22:31:00 2007

On Sun, 8 Jul 2007, Steven M. Bellovin wrote:
Any clue about the root cause, i.e., malice or accident?

Does it matter? You are screwed either way.

It tells us what we need to do to prevent such things from happening in
the future.  For example, most misconfigurations could be blocked if
all routers matched prefixes against originating ASNs, and it doesn't
matter much if the assertion is digitally signed or not -- all that
matters is that the check is done against some authoritative database
run, say, by the RIRs.  (No, that's not quite the right solution, but
it serves to illustrate my point.)  That's completely inadequate
against an attacker.


The bad guys will (almost) always say Oops, it was an accident while
being very clever at deliberatly bypassing every safety feature you
can design into a system.

The foolish guys will (almost) always say Oops, I didn't know while also being very clever at accidently bypassing every safety feature you can design into a system.

Unfortunately engineering can't rely on human intentions. Both the evil and the foolish have the same result. The hope is the foolish will give
up before bypassing the last step, so you keep adding more steps to stop the fool. The hope is the evilish will go after something easier before bypassing the last step, so you keep adding more steps to stop the evil (sic).

As always evil or foolish gals do the same thing as evil or foolish guys.

Its not just IP addresses that exhibit misrouting. But it only occassionaly effects the important or famous enough to attract attention.

http://blog.oregonlive.com/siliconforest/2007/06/rivalry_between_qwest_comcast.html