Category: IPv6


IPv6 Statistics Show Continued Growth – Have You Migrated Your Apps Yet?

IPv6stats–GoogleIt is fun to watch the various IPv6 statistics sites because they continue to show the amazing growth of IPv6 around the world.  The World IPv6 Launch measurements now show Verizon Wireless’ network at 59% IPv6, T-Mobile USA at 43%, AT&T at 25%.  Google’s IPv6 statistics show that traffic into Google web sites globally is about to hit 5%.  And then today Akamai launched new IPv6 trend charts that show IPv6 traffic out of Belgium at 29.2%, from Germany 12% and from Luxembourg and the USA right at 10% with Peru not far behind.

All of this shows that IPv6 deployment is very real!  If you haven’t started migrating your applications so that they will work over IPv6 in addition to IPv4, why not?

Obviously I’d encourage you to buy the book to help understand what you need to do… but you can also view the many IPv6 resources out there on the Internet to learn more!  The key point is that you need to get started NOW!  IPv6 is being deployed globally – will your application work over IPv6?

Code.DanYork.Com Now Back Available Over IPv6

worldIPv6launch-256pxAfter a Reddit thread started up that briefly referenced a 2011 post I wrote about adding IPv6 to Node.js apps, I was contacted by a Redditor who was surprised that my site wasn’t available over IPv6!


I was surprised, too, because this site is hosted on a dual-stack server at Hurricane Electric and has been accessible over IPv6 since June 7, 2011, right before the World IPv6 Day event.

But in checking into it… there was no AAAA record in DNS for “” that would point to the server, so the report was indeed accurate. For regular users this site was not available over IPv6.

It turned out to be one of those system administration issues that can bite you.  A month or two ago, TypePad, the provider I still use for my personal site, experienced a severe DDoS attack that took many sites offline.  They recovered but in doing so changed the way that sites were referenced a bit.  I had to switch to using a CNAME instead of an IP address as I had been doing.  The problem there is that due to the “no CNAME at zone apex” rule of DNS, I could no longer use just “” – I would have to switch to using “”.

The episode highlighted to me, though, the need to be sure I have “Test over IPv6” in my list of things to check after making any major changes to any of my sites!

I didn’t want to switch and so I moved the DNS for “” over to CloudFlare to make use of their “CNAME Flattening” so that I could still use “”.

However, in moving the DNS info from my previous DNS hosting provider to CloudFlare, I messed up.  I didn’t bring across the AAAA record for  Also, very bizarrely, I didn’t have the “Automatic IPv6” setting enabled for – even though it is now supposed to be on by default for all new domains.

So the fix was simple – I added the AAAA record for, and I also flipped the switch on the Automatic IPv6 gateway.  Now both and are fully available over IPv6.

Slides from RIPE66: Making an Application Fully IPv6 Compliant

Today at the RIPE66 meeting in Dublin, Ireland, Bert Hubert of PowerDNS fame gave a great presentation about “Making an application fully IPv6 compliant“:
Slide: Making an application fully IPv6 compliant

The video and audio for the session should be available soon. I very much enjoyed Bert’s presentation and he had a few points that I will think about adding to the next version of the book. One specific point is around collecting statistics. Bert noted that in IPv4 you again typically only have one IP address to worry about for each connection, while in IPv6 you may have many different IP addresses for a connection (or you could have). And so you may need to think about your storage of all that statistics information.

I only had two minor quibbles with Bert’s slides:

  • On slide 11, Bert suggests there could be several different ways of displaying IPv6 addresses with port numbers.  As I stated in the question time, RFC 5952 states that it should be Bert’s choice “a”.
  • On the issue of how to choose whether to use the IPv6 or IPv4 interface, the “Happy Eyeballs” technique defined in RFC 6555 is one that many developers are now using.

Overall, I was very glad to see Bert’s presentation out there as we need to have more such presentations helping application developers think about these issues of migrating to IPv6.

P.S. If you want to easily refer people to Bert’s slides, he provided the very easy URL of:

First Update Started To “Migrating Apps to IPv6” – Any Further Feedback?

After moving through a job change and reaching a steady state with a family medical issue, I’ve finally got some cycles ahead of me to get back to something I’ve wanted to do for several months now… get an update out to this book!

I’m currently writing more text and am looking to do the following to the book in this update:

  1. Add a few more graphics to illustrate points, particularly the “happy eyeballs” concept.
  2. Expand coverage of the “privacy address” issue.
  3. Expand on the issues around Carrier-Grade / Large-Scale NAT.
  4. Add in some of the lessons from World IPv6 Day on June 8th.
  5. Add examples / case studies from people who have gone through the migration of their app over to IPv6.

On this final point, I have a few developers who I am contacting to see if they are willing to share their story, but I am definitely open to including more case studies. If you have migrated one of your applications to work on IPv6, I’d love to hear from you.

Beyond this list, do any of you have other points you would like to see included in the book? Or areas in the book that you would like to see expanded?

Please either leave a comment here or drop me an email to let me know. Thanks!

I’m not sure of the exact timeframe but I’m hoping to get an update out by the end of November.

P.S. Note that any of you who bought the ebook directly from O’Reilly will be automatically notified when the new version is published online.

Want to Learn About Deploying IPv6, DNSSEC? Attend the ION Conference in Toronto on Nov 14th

Would you like to learn about how to deploy IPv6? Would you like to hear from people who are already using IPv6 within their networks? Would you like to learn a bit about DNSSEC and how it can help you secure your online presence?

If so, please join us in Toronto, Ontario, Canada, for our next "Internet ON" (ION) Conference on Monday, November 14, 2011, starting at 12:30pm and sponsored by the Internet Society (my new employer). The sessions on the agenda include:

  • New ISOC Initiative – Bridging the Divide Between IETF Standards and Industry-wide Deployment
  • Panel Discussion: Challenges and Opportunities in Deploying IPv6, DNSSEC, and Other Key Technologies
  • World IPv6 Day Recap (my presentation)
  • Ask the Expert: Next Steps to Implementing IPv6
  • Closing Remarks and Q&A

We're looking forward to providing a great session for people to ask questions and talk about how to get these technologies actually deployed in networks today.

The ION conference is part of the larger 2011 Canadian ISP Summit that takes place on the following two days and is included as part of the registration for the Canadian ISP Summit.

However, registration for the ION conference is FREE if you just want to attend the half-day session on Monday. You can sign up through the Canadian ISP Summit registration page, where one of the available options is for the ION ONLY registration.

(NOTE: If you do sign up for the free ION Only registration, the lunch and dinner listed on the agenda are not included. Those are part of the full registration.)

If you do want to register for the full Canadian ISP Summit, which has a great agenda of technical and business talks , we have a discount code of "ISOCDC" which can get your $50 off the registration if used by November 11, 2011.

We just had a very successful ION event in Buenos Aires last month and we're looking forward to great conversations and discussions up in Toronto - I hope to see you there!

P.S. A couple of people have already asked me if I'm going to be able to spend more time in Toronto (and meet them). Unfortunately due to family medical issues I'm just in Toronto for Monday and will be flying back Tuesday morning. Normally I would have loved to stay for this full event because some of the other sessions look great - and Toronto is also an outstanding place to visit.

If you found this post interesting or useful, please consider either:

Time Warner Cable Seeking More Volunteers for Residential IPv6 Trials

Ipv6 200If your cable company here in the USA is Time Warner Cable and you get your high speed Internet access through them, they are looking for more volunteers for their residential IPv6 trials. This message below went out yesterday to the NANOG mailing list:

Time Warner Cable is expanding our residential IPv6 trials in several markets, and we need more people. If you’re a Time Warner Cable High Speed Internet subscriber, and are interested in participating in our IPv6 trials, please let us know! We have a short form at

that will help us find the right mix of people, equipment, and locations, to get the most out of our trials.

Thanks in advance for participating!

As a Time Warner Cable subscriber, I immediately headed over to complete the form. My whole home office uses IPv6, but it’s through a tunnel out to and while that works okay, I’d love having native IPv6.

Now, whether or not little old Keene, NH, qualifies as one of the “several markets” to which they are expanding their trials remains to be seen…

Looking For IPv6 Application Migration Case Studies To Include In The Book – Care To Share Yours?

Ipv6 200As I have continued to talk and speak about IPv6 and issues around migrating applications over to IPv6, one of the themes that has repeatedly come up is that developers are looking for examples of people who have gone through the migration from which they can learn.

Understandably, they’d like to know what pain – or NOT – other developers had to go through to migrate their app to work on IPv6.

With that in mind, I’m thinking of adding a new section to the book with specific case studies around apps that moved successfully into a IPv6/IPv4 world. Basically capturing what the developers did or did not do, what they had to change, how their application needs to be configured to work with IPv6 (if it does), etc., etc.

I have several companies and individual app developers that I will be contacting to include, but the beauty of an e-book is that there really isn’t a limit on what I can include in terms of length. So…


I have some questions I’d like to ask you about what you’ve done, the challenges (or lack thereof) you encountered, etc. I expect that an email exchange is all that is needed, although if you are interested I’m toying with maybe also doing some video interviews as well (typically via Skype video).

Please do contact me if you’re willing to share your experience. Working together we can build a compilation of case studies that can help more people make the move to IPv6! Thanks!

Slides: Impact of IPv6 on Telecommunications Applications

At the recent Emerging Communications (eComm) Confernce 2011 I spoke about “How IPv6 Will Kill Telecom – And What We Need To Do About It“. It wasn’t all about applications – I also got into the impact of IPv6 on telecom protocols – but still I thought that some of you may find my slides of interest. I do include several examples of issues facing applications:

At some point a video of the session will be online and I will provide a link here when that is available.

What’s Wrong With This IPv4 Application?

See any problem with entering IPv6 addresses using this user interface? Probably not going to work to well, is it? 🙂

Iphone ipv4

This is just the network config interface of an IP phone I had on my desk. While some of you from the VoIP world might recognize the vendor, the truth is that most IP phone vendors’ apps have similar interfaces. These are the type of user interfaces I discuss in Chapter 1 of the book and that will be one of the biggest challenges for app developers. In the case of IP phones, the challenge is even greater because it is running on an embedded device using typically a special-purpose operating system.

Where do you have user interfaces like this lurking in your applications?

Demonstrating IPv6 User Interface Issues – with the web site theme!

Rather ironically, I have found that the WordPress theme I’ve been initially using for this site demonstrates perfectly the kind of user interface display issues that will bite so many developers with IPv6. Here’s a screenshot of me visiting the site from an IPv6 site (part of the address covered for security purposes):

Ipv6 design

As you can see, it goes well outside the column containing the box with the address in it.

In contrast, over on I’m using a different theme and the same exact widget displays the IPv6 address fine there:


The big difference is the style sheets use a smaller font size and the column is also bigger.

I’m not too worried about the display here in the current theme because I’m going to be changing the theme for a couple of reasons (it may even have changed already by the time you read this post). But it serves as precisely the kind of user interface issue that application developers will need to examine.