Today is World IPv6 Launch Day. It's the day the internet gets some more legroom, headspace, and elbowroom, too.
Internet pioneer Vint Cerf calls it the launch of the "21st century internet," but what's really happening is that a number of internet giants -- Google and AT&T and Comcast and Facebook, to name a few -- are turning on new gear that will help solve a very big problem. In essence, they'll inflate the internet's address book from the equivalent of a flimsy back-pocket notebook to a long row of libraries filled with deep ledgers.
It's a big step for the internet, one that's been brewing since 1990, when an engineer named Frank Solensky made a back-of-the-envelope prediction to a few hundred internet engineers at a technical conference in Vancouver, British Columbia.
Back then, most people hadn't heard of the internet. And companies or schools that wanted to use it were allotted vast swaths of the Internet Protocol (IP) addresses used to identify computers on the emerging global network. Many of them were getting too much address space, and Solensky could see that at the rate things were going, there wouldn't be any more addresses to give out if they kept using the existing IPv4 system.
He campaigned to fix the problem, and on Wednesday, the patch, called IPv6, will roll out on some big websites. (Before you ask, IPv5 was an experimental streaming protocol that never went anywhere)
IPv6 is coming not a moment too soon. Solensky thought we'd run out of IP addresses sometime around 2002, but back then, he didn't know about the nifty tricks that engineers would cook up to let computers share IP addresses, effectively extending the lifespan of IPv4 by another decade. But the last unused block of IPv4 addresses was assigned last year. Without IPv6, it's going to eventually become really hard for internet service providers and corporations to add new machines to their networks.
To put it in perspective, IPv4 can handle just over 4 billion addresses. IPv6 spans 340,000,000,000,000,000,000,000,000,000,000,000,000.
The group that develops the internet's protocols, the Internet Engineering Task Force, took Solenksy's warnings seriously back in the 1990s. "It got people aware that there was a problem. Before then, nobody really thought about it," says Scott Bradner, an Harvard senior technical consultant who has co-chaired a committee charged with solving the coming address-space shortage. "The IETF leaders looked at that and said: 'Whoops, there is a problem.'"
They published proposals -- this was before the web, so they were shared via FTP -- and kicked around a few ideas. After a two-day retreat just outside of Chicago in 1994, they settled on a proposal cooked up by a Xerox PARC researcher named Stephen Deering. It was called the Simple Internet Protocol.
By 1995, he and another internet guru, Bob Hinden, had written a first draft of IPv6. And with a few minor technical changes, that's pretty much the protocol that Google and Facebook and others are rolling out today. "They did a good job," says Bradner. "The basic structure stayed the same."
The way Hinden remembers it, he didn't think it would take another 17 years for IPv6 to become widespread. "We all knew it was going to be hard, but I don't think we imagined that it was going to be as hard as it turned out to be."
Why the delay? In a nutshell: money.
In the early, academic days of the internet, geeks would excitedly update protocols and gear because, technically speaking, it was the right thing to do. But by the time IPv6 got drafted, the internet was becoming dominated by companies. And if they were going to upgrade their systems, they needed a financial justification. In other words, they needed to run out of address space.
If you use Android or the iPhone, or a version of Mac OS or Windows that was released in the past five years, it probably supports IPv6 as well as IPv4. The big problem has been that websites, household routers and consumer internet service providers have not supported it. And for IPv6 to work internet-wide, everybody needs to get on board -- PCs, routers, and websites too.
So far -- other than a moving animated turtle in Japan -- there hasn't been much to see, even if your desktop, routers and service provider all supported IPv6. A year ago, some companies switched IPv6 on temporarily, just to test it out. But as of today, Facebook, Google, Microsoft Bing, and Yahoo are going to flip on IPv6 full time.
That doesn't mean IPv4 is going away. None of the big Web companies are going to drop IPv4. They're just adding IPv6 as another option. And service providers such as Akamai, AT&T, and Comcast are going to do the same thing. "The idea here is to get more and more of the internet IPv6 enabled so people can use their IPv6 environments to get there," says Bradner.
In fact, Bradner thinks IPv4 will be around for a long, long time. But there's an insatiable demand for internet-capable devices, and soon companies are going to start leaning on that brand new IPv6 address space. And the more systems out there that support the same protocol, the easier it will be for everyone to find each other in this brand new internet.
Happy World IPv6 Launch Day.
