www.daork.net

I’ve been doing lots of teaching IPv6 lately. At an InternetNZ IPv6 training day in Wellington in ‘07, at NZNOG’08 in Dunedin, and also private training for a few companies and things.

I figure the world is better off if I post up slides and things, as opposed to keeping them secret or proprietary or whatever. If you rip them off, make sure you let me know and give credit and all that noise.

• InternetNZ, talking about transition technologies: 20070809-nward-6to4-teredo.pdf
• NZNOG’08, talking about 6to4, Teredo and my Tui project: 20080124-6to4-teredo-tui.pdf

More to come, when I get em uploaded.

I’ve refined my previous idea slightly:
- IMG tags have src set to “” to start with.
- JavaScript thing runs on page load, and starts a timer, and sets src properties for the 3 images.
- A new IMG tag exists. It’s src is set to deliver results back to me.
- When the first imge loads, a timer is kicked off.
- When either the last image loads or the timer fires, the results IMG src is set to send some data to the server, including: ipv4 loadtime, ipv6 loadtime, ipv6and4 loadtime. Where images don’t load, NaN is sent.
- When the timer fires, the src of the various IMGs is optionally set to “”, to stop the test.

I think that’s about it.
I’ve been running this for a few days on my websites. At least one of them isn’t small and has a wide range of users from non-technical to pretty-technical, and a wide range of OSes and browsers.

The code has been published at:
http://www.braintrust.co.nz/ipv6wwwtest/

Enjoy.

During a discussion on the NANOG list today about IPv6 deployment/migration, I came up with a way to test how many of your websites’ viewers can reach you on IPv6, and who would have problems if you turned AAAA records on.

Basically, drop 3 image tags in to your site:
- http://ipv4test.domain.com/ipv4test.gif
- http://ipv6test.domain.com/ipv6test.gif
- http://ipv6and4test.domain.com/ipv6and4test.gif

Set the “onerror” for these images to change the src to:
- http://www.domain.com/ipv4error.gif
- http://www.domain.com/ipv6error.gif
- http://www.domain.com/ipv6and4error.gif

Another good idea is to have the onerror event set onerror to ”, so it doesn’t loop if it can’t get to your main site for some weird reason.

These images should all be 1×1 transparent gifs. That’s a whopping 43b filesize, so don’t worry about bandwidth.

Comparing the hits against these 6 images should tell you roughly who’ll break if you turn on AAAA records.

Further work and things for me to try:
- Set timers to start on page load, and stop on load of each of those images, and then POST it.
- Check network traffic to addresses that the image URLs point to, and analyse it against logs. Points of interest are connections that don’t fully open, and requests that don’t arrive.
- Put many images in, with long URLs, so upstream MTU can be tested.
- Have those images vary in size, so downstream MTU can be tested.