IPv6: Are we there yet?

April 28, 2010 Earl Zmijewski


For an advanced technology that we all depend upon, it sure seems that the Internet has more than its fair share of problems: spam, viruses, malware, spyware, phishing, worms, trojans, DDoS attacks, hijacks, DNS cache poisoning, botnets, keystroke loggers, etc. We need an entirely new vocabulary just to talk about this stuff. Most of it appears to come out of the blue, forcing the rest of the world to react. But the good news is that there is at least one problem we can do something about in advance. Unfortunately, not everyone has been taking the problem seriously enough and we are about to hit the wall.

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.


The Internet Engineering Task Force (IETF) started looking into creating an IP Next Generation (IPng) protocol in 1992. After a six-year gestation period, IPv6 was born with the publication of RFC 2460 in December 1998. Twelve years on, the various Regional Internet Registries (RIRs) are projected to exhaust their IPv4 allocations from IANA within two years. After that, there will still be plenty of unused IPv4 addresses, but they will all reside with existing companies, governments, schools and organizations. New entities are going to face a serious problem acquiring IPv4 addresses. And what about the over 4 billion mobile phones in use globally today, all of them potentially Internet-capable devices? The need for new addresses is only going to increase dramatically.

IPv6 Routing and DNS

Among other things, Renesys collects both IPv4 and IPv6 routing data from various exchange points worldwide. From this data source,
we have seen a marked increase in allocated, registered and routed IPv6 prefixes (blocks of consecutive IP addresses) over the past year. In addition, the number of Autonomous Systems (ASes) observed originating IPv6 prefixes has been on the rise. The graphs on this page show the growth rates in these metrics over the past 18 months. A view into the IPv6 marketplace can also be found in Renesys’ latest version of Market Intelligence.


IPv6 is supported in all major modern operating systems, including Windows, Mac OS and Linux, and is enabled by default or easily activated. In DNS, IPv6 addresses are looked up via AAAA-type queries, also known as quad-A. The ratio of quad-A queries to total DNS query volume, now 15 – 20% on busy servers, provides solid evidence of the increasing prevalence of IPv6-capable clients.

While Google has supported IPv6 access to its search engine since March 2008, this year it turned on IPv6 support for YouTube, resulting in an immediate and sustained jump in global IPv6 traffic. And with over 15 million Internet subscribers, Comcast has announced extensive IPv6 trials starting in the second quarter of 2010. The biggest players on the Internet cannot afford to have their businesses constrained by lack of IP space and have been at the forefront of IPv6 adoption. With major content providers and ISPs enabling IPv6 transit and popular operating systems turning on support by default, is an IPv6 Internet now a reality?

Drum roll, please …

Not really. We still have a very long way to go. Of the over 34,000 ASes in use on the Internet, only around 6% (just over 2,000) handle IPv6 prefixes (i.e., the ASN is seen in the path of an IPv6 announcement). Of the top 100 global providers according to Renesys’ Market Intelligence rankings, only 28% originate more than one IPv6 prefix and 36% originate none. These are very low bars for measuring success. It does not imply that the providers have IPv6 content, only that they lay claim to some IPv6 space or can pass along an IPv6 routing announcement.

Thumbnail image for ASN_IPv6_6_cmyk.jpg


In summary, if you possessed an IPv6-only device and had no way to NAT your way to the “real” Internet, you’d probably be rather lonely. Even the rather small IPv6 world is not completely connected. At the end of March, we randomly selected two global providers who supply us with their IPv6 routing tables, call them A and B. Considering all possible covering routes, provider A had 30 IPv6 prefixes not reachable from B, while B had 19 prefixes not reachable from A (2,643 prefixes could be reached from both). While much of the machinery necessary for IPv6 is currently in place, the content, the availability and even the basic connectivity of the network continues to be lacking. But this much is certain, we will run out of IPv4 address space and IPv6 is the only other game in town. The fine folks at Hurricane Electric even provide a nice app to let you count down the days until IPv4 exhaustion. So even though the iPhone still doesn’t support IPv6 natively, if you want to reach the billions of mobile Internet users yet to come online, you are going to have to support both IPv4 and IPv6 before long. Time is running out for those still on the sidelines, as the growth of the Internet shows no signs of slowing down.

The post IPv6: Are we there yet? appeared first on Dyn Research.


About the Author

Earl leads a peerless team of data scientists who are committed to analyzing Dyn’s vast Internet Performance data resources and applying their expertise to continually improve upon Dyn’s products and services.

More Content by Earl Zmijewski
Previous Article
Two Strikes For the I-root
Two Strikes For the I-root

Here we go again. In March we wrote a blog entitled Accidentally Importing...

Next Article
How To Build A Cybernuke
How To Build A Cybernuke

The Internet infrastructure has been having a bad month. Not as bad as, say,...