If you put 65 million people in a locked room, they're going to find all the exits pretty quickly, and maybe make a few of their own. In the case of Iran's crippled-but-still-connected Internet, that means finding a continuous supply of proxy servers that allow continued access to unfiltered international web content like Twitter, Gmail, and the BBC.

We've received enough interest about our previous notes on Iranian Internet connectivity that I wanted to give a brief update, and some reflections.

Seventy-five years ago today, on May 29th, 1934, Egyptian private radio stations fell silent, as the government shut them down in favor of a state monopoly on broadcast communication. Egyptian radio "hackers" (as we would style them today) had, over the course of about fifteen years, developed a burgeoning network of unofficial radio stations. They offered listeners an unfiltered, continuous mix of news, gossip, and live entertainment from low-powered transmitters located in private houses and businesses throughout Cairo.

It couldn't last. After two days of official radio silence, on May 31st, official state-sponsored radio stations (run by the Marconi company under special contract) began transmitting a clean slate of government-sanctioned programming, and the brief era of grass-roots Egyptian radio was over.

Across the Internet, yesterday, Google users twittered, blogged and emailed that Google search and mail were not usable. And, yesterday afternoon, on Google's official blog, Urs Hoelzle reported that Google "direct[ed] some [...] web traffic through Asia".

A couple of months ago, we discussed how a small Czech provider ended up causing global Internet mayhem by tickling a Cisco bug via a rather ridiculous routing announcement. While it's easy to fault the instigator of this meltdown, ultimate responsibility belongs with the vendors of poorly tested code. If we've learned anything in decades of software engineering, it is that you can't assume anything about user input. If you don't check that input for validity, you are not just being careless, you are creating a time bomb that will eventually go off. Another such bomb went off on Sunday, 3 May 2009, taking out a large swath of the Internet. We recount the sorry tale here.

In our last blog entry, we talked about measuring the state of routing anarchy that exists on the Internet on a per-country basis. We looked at every routed network (prefix) by country of origin and tried to answer the question: do folks do what they say and say what they do, as articulated via routing registries? Although many manage to administer their routes with care, the overall results are quite varied. And without some way of verifying routes via some authoritative source, we are left only with the current system of believing everything we're told and hoping for the best. The dangers of such a system are demonstrated dramatically from time to time.

Although they certainly could, countries typically don't exercise any control over the routing hygiene of the companies operating within their borders. Countries might tax those companies, filter their traffic for objectionable content, mandate the types of software or equipment they can use and even spy on them, but if a company wants to screw up routing on the global Internet, well that's their business. As we've noted in the past, no driver's license is required on the Information Superhighway, as there are essentially no rules, regulations or enforcement. So in this blog entry, we'll apply our scoring idea to those who can easily effect change, namely, those organizations who are ultimately responsible for how traffic flows on the Internet.

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.