Following last year’s World IPv6 Day event, the Internet Society has announced that this year June 6th will instead see the World IPv6 launch. Rather than content providers just turning on IPv6 access to their sites and services for 24 hours, this time the switch will be permanent. A full list of participants is listed on the web site.
This means that from June 6th 2012 major content providers such as Google (and their associated sites like YouTube), Facebook and Akamai (who offer content delivery services) will turn on IPv6 and leave it on. If applications query such providers for DNS records, they will receive both A (IPv4) and AAAA (IPv6) records back, and the application can then decide which to use.
So sites on JANET, and indeed anywhere else, need to consider what will happen when June 6th comes. In principle, if you have no IPv6 configured at your site, your applications and browsers will just continue to use IPv4, and you won’t notice any difference.
However, should you have IPv6 accidentally configured by administrators or users, or you have Rogue IPv6 Router Advertisements in your network, you may find your users see delays and even connection failures as a result. This is because all common operating systems and devices now ship with IPv6, and with it on by default.
Ensuring your network is properly protected from such traffic, which is typically seen as a result of certain Windows Internet Connection Sharing configurations, is thus quite important. Looking for RA Guard support in switching equipment is one approach, running a tool like RAmond is another. The Firefox and Chrome browsers support a version of Happy Eyeballs, which means they will try IPv6 first but also try IPv4 a few hundred milliseconds later, and they then use the first connection to establish. A bigger hit on web servers, but a better user experience. Safari, and Mac applications, use a different heuristic to determine which protocol to use, generally preferring what works best (not great for IPv6 deployment, but good for users).
Avoiding use of “transition” protocols such as 6to4 and Teredo is also important. The latest IPv6 stats from Google show native IPv6 on the rise, albeit only at 0.48% worldwide, and (unreliable) transition techniques in decline.
The World IPv6 Launch is also promoting the deployment of IPv6 access networks by ISPs. At present, very few commercial UK ISPs offer native IPv6. In the US, AT&T have reportedly committed to enabling 5,000,000 customers by the end of the year. In France, Free.fr have several hundred thousand IPv6 customers, using an internal tunnelling solution called 6rd, and are shipping an average 20Gbit/s of IPv6 traffic. It’s disappointing none of the big UK players are following suit, yet.