IPv6 and its various incarnations-Collection of common programming errors

I’ve been using IPv6 since 2006, when all there was to see was a dancing turtle*, so I can tell you it is very much live on the Internet today. Major websites such as Google and Facebook are already live with IPv6 and if you have IPv6 connectivity from your ISP then you will already connect to them using IPv6.

June 6, 2012 was designated World IPv6 Launch Day, where ISPs, network equipment manufacturers and web site operators committed to deploy IPv6.

To obtain IPv6 connectivity at home, contact your ISP and ask them when they plan to deploy native dual stack IPv6. If the answer is anything but “We already did” and you still want to experiment with IPv6, you can obtain temporary service from an IPv6 tunnel broker such as SixXS or Hurricane Electric. (I use the former in places I can’t yet get native dual stack.)

When you obtain IPv6 service as a residential customer, you typically will be granted a /64 subnet, which provides about 4 billion times the amount of address space of the current IPv4 internet – just for your house. It would be virtually impossible for you to use your entire allocation. Even so, business customers can typically obtain additional addresses; I could have a /48 just for the asking if I had even the slightest reason to get such a block.

A typical business will typically have somewhere between a /48 and a /56 depending on the complexity of their internal network. ISPs will have much larger blocks; US cable ISP Comcast has a /31, for instance, from which it delegates blocks to its IPv6 customers.

Whether you experience improved latency or performance depends in large part on where you connect to and what you do when you connect there. For the most part your performance should be virtually identical, give or take a millisecond or two. I know of a few degenerate cases where my IPv6 route dramatically outperforms my IPv4 route (we’re talking 120ms round trip on IPv4 and 90ms on IPv6), but none of the reverse.

As for software telling you to disable IPv6, some antique software may still not support IPv6 or may malfunction when IPv6 is deployed, or even simply on an IPv6-capable computer. This of course is a bug with that software, and the software vendor should provide an update (if they’re still even in business, which is questionable if any such software is still doing that in 2012). IPv6 has been an RFC for close to 15 years now, and so there’s very little excuse for any current software to lack support for it.

(*The turtle only dances if you connect with IPv6.)