I'm talking about the impending exhaustion of IP addresses, IPv4 addresses to be exact. Every computer on the Internet needs access to at least one unique address in order to be connected. Around the dawn of the Internet, 32-bit IPv4 addresses, which allow for 4,294,967,296 different possibilities, seemed like more than enough. This was a simpler time when computers cost millions and no one imagined a phone you could put in your pocket. As the Internet grew, it soon became obvious that the seemingly inexhaustible supply of 4 billion addresses wasn't quite enough. And so, a 128-bit IPv6-based Internet was proposed, this one with 340,282,366,920,938,463,463,374,607,431,768,211,456 different addresses. (We're not going to make that mistake again!) The only problem was that the new Internet wasn't interoperable with the old one we already knew and loved. Without a Y2K-type hard deadline to focus on, we kept barreling along toward the edge of the IPv4 cliff. Now that the edge is clearly in sight, this blog looks at how far we have come in adopting the not-so-new-anymore IPv6 Internet and, perhaps more importantly, how much further we need to go.

First, Chinese Internet censorship leaked out to a few massively unlucky users of the I root server. Then China Telecom failed to filter someone who leaked thousands of hijacked routes to other people's networks through them, probably by accident.

And then, inexplicably, Forbes went where no one had gone before (with a wink to Wired), and asked whether China might actually be testing a "cybernuke".

At first, this irritated me. Journalists and bloggers and blogger-journalists are fanning the flames of US unease about the growing role of China in world affairs. But then I realized that I could probably make tens of thousands of people read my blog, too, by jumping on the bandwagon. By all means, then, grab an MRE and hunker down in your Internet bomb shelter while I try to answer some of the obvious questions that came our way in the wake of the Forbes article:

• How would anyone build a cybernuke? What is that?
• Could a single actor, state-sponsored or otherwise, actually take down the global or regional Internet infrastructure of 2010, disrupt financial markets, throw civilization into chaos?
• How do I get my cybernuke movie screenplay optioned by Jerry Bruckheimer? His people won't return my calls.

]]> http://www.renesys.com/blog/2010/02/irans-internet-the-geopolitics.shtml http://www.renesys.com/blog/2010/02/irans-internet-the-geopolitics.shtml Internet Thu, 11 Feb 2010 07:59:18 -0500 As our faithful readers know, Renesys monitors routing on the global Internet in real time and uses that information in a variety of ways. For example, we can instantly let you know which networks a hurricane has disabled or even tell you when a war has left things pretty much as they were. In short, we keep an eye on the Internet, the entire Internet, but this is all done at the level of IP addresses and the paths they follow.

The recent attack on Twitter got us thinking. Maybe we should be keeping an eye on a few more things? While your IP addresses and routes to them might be completely stable, the average user doesn't know about those. In other words, when was the last time you typed ...
    http://216.239.59.104
instead of ...
    http://www.google.com
into your browser?

What if someone manages to point your domain name to some other IP addresses? You would still be operational as far as the Internet routers were concerned, but no humans would probably be reaching you. And that's the problem we'll briefly consider in this blog.

Organizations need an ASN to run BGP and route on the Internet. They are each assigned globally unique ASN(s) by their local Regional Internet Registry (RIR), who get them from IANA. A few weeks ago, the NANOG folks noticed that AS1712 had been registered by two different organizations (in France and Texas) that were both using the number to announce their separate network prefixes. ARIN issued a statement conveying that they were aware of the problem and were working to resolve it. We took a look at the data and found that AS1712 isn't the only dually-assigned ASN out there. In fact, even a root server didn't escape unscathed.

Think you're too busy to blog? Think again. Or just ask your boss. After more than 100,000 miles in coach class this year (so far), my backbone may be aching, but the IP backbone market is as agile and dynamic as ever. Sales opportunities abound, but to take advantage, you'd better be savvy, and just a little cagey.

So, as our gleaming 777 departs Kuala Lumpur, I'll just relax in my fully-reclined, ultra-deluxe coach seat and tell you what this globetrotting sales guy has seen, heard and figured out.

1. Large eyeball networks (5 million+ subscribers) are selling paid peering to the largest content providers.
2. There are big price reductions in IP transit all over eastern Europe - now close to parity with western Europe.

Here We Go Again.

Imagine an innocent BGP message, sent from a random small network service provider's border router somewhere in the world. It contains a payload that is unusual, but strictly speaking, conformant to protocol. Most of the routers in the world, when faced with such a message, pass it along. But a few have a bug that makes them drop sessions abruptly and reopen them, flooding their neighbors with full-table session resets every time they hear the offending message. The miracle of global BGP ensures that every vulnerable router on earth gets a peek at the offending message in under 30 seconds. The global routing infrastructure rings like a bell, as BGP update rates spike by orders of magnitude in the blink of an eye. Links congest. Small routing hardware falls over and dies. It takes hours for things to return to normal.

And this applies to other complex systems besides the Internet. I was in India during 9/11 and, for two days, I could not make a traditional phone call to the US. Why? Everyone in India knows someone in NYC, and they all picked up the phone at the same time to check in on them. The circuits were so overloaded, I couldn't even get the friendly "Your call cannot be completed as dialed" message.

No system is ever going to be engineered for insanely high loads. If everyone in your town decides to take a shortcut through your neighborhood to avoid an accident on the highway, you are going to have trouble getting out of your driveway. But rather than give up and wait it out, there is something you can do in advance and at reasonable cost: build a second driveway to a different street on the other side of your house, one that isn't fed by the same access roads from the highway. This blog is about building such redundancy into your Internet connectivity, so you aren't disconnected by a single failure. And while it's good that the New York Times and various governments are watching the problem, if your business depends on the Internet, you're largely on your own to audit and verify that you are buying a sufficient level of redundancy for your budget. A lot of fragility problems could be solved by more informed consumers performing the necessary due diligence.