www.daork.net

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.

So, I’ve decided to write a network element manager, along the same lines as Dorado RMC.

The idea is that it will be an application that will:
- Do config backups
- Deploy config with templates, config snippets, etc.
- Check that current config meets certain rules
- Use interoperable XML/SOAP stuff for as many interfaces as possible, so it can be swapped out.
- CLI and web GUI to start with - adding maybe a GTK+ or Java GUI later on. I’d also like to do a Cocoa GUI for OS X.

And more things, I’m busy at work so it’s hard to think of all the things I have considered recently, but I’ll edit this post as I come up with more key points.