On Wed, 26 July 2000, Scott Marcus wrote:
Sean, I don't think that they were arguing that EVERY failure would cause this kind of collapse. They were saying that a scale-free system might be particularly vulnerable to a systematic attempt to cripple its most critical elements. A failure of a single public NAP is probably well below that threshhold.
I agree the failure of a single public NAP is below the threshhold stated in the article. But I think we can use data from actual failures at NAPs to help with the forcast. One interesting, and I think important piece of missing data is when a major NAP does fail new paths become visible in the network. The physical destruction of a NAP eliminates some paths, but I'm not sure how well the NLANR data really shows what happens with the connectivity. Of course the 'new' physical paths aren't created out of thin air. They are just lost in the shadows behind the hot glare of the big pipes. An open question is there enough shadow paths in the Internet to heal it, or are we just talking about degrees until total failure. I'm not sure the article author's took this into account. Secondly, must of the popular discussion (i.e. comments from the FBI's National Information Protection Center, SRI's Atomic Tangerine, etc) has used the article to support the theory the net is very vulnerable to terroristic attacks. However, destroying 2.5% of the nodes in the Internet is a big number. Its not just a matter of blowing up a parking garage outside Washington DC, a Gigaswitch in San Jose, etc. Launching a coordinated attack against 25, 250, 2500 different physical locations worldwide is hard for even an organized military operation. If terrorists blew up the top 2.5% of the largest cities in the USA, would the country would break up into feudal segements. I don't know. I agree things would be very grim if 2.5% of the cities were destroyed. But that is not small terroristic attack. I don't think the article supports the notion the Internet is exceptionally vulnerable to physical attack by terrorists. Actually, I think the article supports exactly the opposite view, it takes a rather large physical attack to partition the net. On the other hand, I think the current operational practices make the net less resiliant to certain forms of attack. But that is a different discussion.