Sometimes I think I should have been a network engineer. I love all that "belly of the internet beast" stuff—giant high-speed routers, huge data pipes, and all things close to the backbone of the Internet. But then I remember my grades from my engineering classes, and why I dropped engineering, and switched my major to English. Perhaps the engineer who broke both YouTube and the Pakistani Internet yesterday should have switched his major, too, before it was too late. I mean, I wouldn't want to be that guy right now. Would you want to be the guy who kept Pervez Musharraf from getting to his MySpace page?
It all stems, of course, from Pakistan's recent directive to its country's ISPs to block YouTube because of videos of those supposedly blasphemous Dutch cartoons. Yes, that again. Won't die, will it? In a nutshell, when someone in Pakistan modified some routing tables to direct all Pakistani traffic to YouTube into a black hole, the routing information escaped national boundaries by way of Hong Kong, and began routing worldwide YouTube traffic to that Pakistani black hole. Whoopsie. I give credit to Ars Technica for a detailed and fascinating explanation of the underlying problem.
Apparently, the problem was corrected in a couple hours, and the consensus seems to be that it was an accident. If it was a concerted attack, or a test of attack methods, it certainly would have been a clumsy one, since it essentially resulted in a DDOS attack on the hypothetical attacker's own country. About as effective as a lit stick of dynamite strapped to a boomerang, really.
But that doesn't mean there isn't a huge vulnerability underlying this whole incident. It's conceivable that an attacking country (or other entity), if it were well prepared and didn't care all that much if innocent bystanders got cut off from the world, could use this routing vulnerability to strike at an enemy. It all depends on how desperate they are, and how willing they are to cripple the Internet as a whole. Gee, it doesn't seem too difficult to think of one or two groups who might fit that bill.
I suppose there's reason to hope that this incident will throw the spotlight back on a vulnerability that we've known about for years, but have never gotten around to fixing. That fix won't be easy, but clearly it's necessary.