Since Renesys maintains large quantities of data on the Internet going back many years, we sometimes get the question: If you guys are watching the entire 'net, why don't you just warn people when things break? My response is generally along the lines of: Sure we can do that. Simply tell us the correct state of the Internet at each moment in time and we'll alert you to any operational differences we observe. This is generally met with silence.
Renesys can tell you a lot about the current state of the Internet, but absolutely no one can tell you the correct state. And that is because no one is in charge, and so there is no central authoritative source of information. Think of the Internet as a highway system where anyone can buy a car and simply start driving: no need to register the car, attach a license plate, buy insurance or get a driver's license. You don't even have to show an id or be sober. Just pay some fees, buy some equipment, hook up and go. The barrier to entry really is that low.
Obviously, this arrangement can cause some problems. When Pakistan hijacked YouTube last year by announcing YouTube IP space, out of the hundreds of thousands of routing announcements seen on Internet, how was anyone to know this particular one was incorrect? Okay sure, you couldn't get your videos, but maybe YouTube had just opened a data center in Karachi and the problem was internal to them? Without some way of checking the authenticity of routes, the routers that direct traffic on the Internet simply believe what they are told. And if the best route to YouTube appears to be via Pakistan, then they are all going to use it, no questions asked. This is not a new problem, and this blog explores an old and largely failed attempt to address it. We then compare the differences between countries with respect to their routing hygiene.
