Of course, of those millions of users, very few have IPv6 connectivity, but it’s vital for IPv6 deployment that big sites can go dual-stack without adversely affecting ‘legacy’ IPv4-only networks, and that was a key issue for W6D.

I ran tests on W6D against a list of .ac.uk sites that I obtained, and this showed some 18 JANET-connected sites who had their web sites dual-stack enabled for the day. These included Loughborough, Imperial, Oxford, Cambridge, Leeds, Sheffield, SOAS, Reading, Cranfield, Sanger and Totton College. Some of these were dual-stack already, and some were only enabled for the day, but congratulations to everyone who took part, it was great to see! A number of these sites have their computing service operations split such that web servers and networks are run by different teams, so one of the benefits of W6D participation was getting these teams – and in some cases others – talking, leading to a successful deployment.

Putting up dual-stack IPv6 content was the main thrust of W6D, with obviously Google (and thus YouTube), Facebook, Yahoo, CNN and the BBC being some of the big players. The content also allowed sites with some IPv6 client deployment to see what impact the extra IPv6 content would have on their systems. Rob Evans wrote a
blog article in which he showed how JANET IPv6 traffic grew for the day, up from 20-30 Mbit/s to 200 Mbit/s+. While not big numbers, that’s a pretty significant jump.

The good news is that W6D was successful enough that many providers have left some significant presence available over IPv6 since the day. User-contributed YouTube content is still being served dual-stack, as is Facebook’s developer site at developers.facebook.com, while Microsoft have left www.xbox.com available over IPv6. It’s enough content overall that JANET IPv6 traffic is still significantly up from pre-W6D levels, as Rob’s data shows.

Here at Southampton, in ECS our traffic levels were somewhat quiet due to W6D being the week after exams ended, but we saw peak IPv6 data rates up to 400 Mbit/s with some external file transfer tests, and over the course of the day some 15% of the external traffic we exchanged was IPv6. Of course we had asked our users to help test IPv6 by looking at YouTube and Facebook content, and they seemed happy to oblige!

So overall, W6D was good, and the interesting question is what next? Well, for JANET-connected sites we have over 100 IPv6 prefixes allocated, and we saw 18 of those sites doing something visible during W6D. The trick now is to determine how to promote further deployment, be that in public-facing services, running IPv6 to Compute Science departments, or perhaps IPv6-enabling eduroam wireless networks. This will be the main topic at JANET’s IPv6 event later this autumn – more info next time.

How might this affect you? It’s worth checking out the latest blog by Rob Evans for a view from the JANET ops perspective, which discusses the potential impact for JANET-connected sites.

If you have some IPv6 clients enabled in your site, then on the 8th these will start using IPv6 to access many services that are normally IPv4 only, including Facebook, Google, YouTube, CNN, the BBC (we believe) and other content. So your IPv6 infrastructure which might normally see 1-2% of external traffic being IPv6 will perhaps see 15%-20%. It’s a very useful one-day glimpse into the IPv6 future. As such, you should try to gather as much information on performance and behaviour as you can, be that raw traffic counts or detailed flow data.

If you have enabled some public-facing servers, typically your main web site (or the load balancers in front of it), an increased number of visitors will be hitting you over IPv6. This gives you an opportunity to validate your deployment method, and to measure IPv6 ‘brokenness’, i.e. how many and which clients have problems reaching you. While this figure is a fraction of 1% by most recent reports, tools like APNIC’s IPv6 Capability Tracker can help with that, using Google Analytics, which has some excellent visualisation tools.

But what if you have no IPv6 at your site? Well, it’s still possible some of your systems will have connectivity issues, if you either have ‘rogue’ IPv6 Router Advertisements (e.g. from Windows ICS being turned on unintentionally) or systems try to use automatic IPv6 tunnelling methods. So you should be aware of these, and check resources like ARIN’s IPv6 wiki to determine which types of problems could occur and what to do.

In general, upgrading your browser or OS is a prudent step, particularly for MacOS X 10.6, where the latest versions are more resilient to rogue RAs. The new Google Chrome is also a good ‘workaround’, since it tries both IPv4 and IPv6, and falls back to IPv4 very quickly (300ms) if it experiences IPv6 connectivity problems. Microsoft have also published an updated KB entry that you or your users can apply to just have them prefer IPv4 until June 10th (when the patch expires).

There are quite a few sites offering IPv6 stats around World IPv6 Day. These include the RIPE NCC v6day data, some Google statistics and stats from the AMS IX. There’s other stats sites linked to the right.

We understand that some BBC content will be made dual-stack for the day; an IPv6-only preview exists here. There’s a Facebook announcement, while Blizzard are also enabling IPv6 access for certain realms. CNN have announced their readiness this week, while MS have already made xbox.com dual-stack.

Tomorrow is going to be a very interesting day. Do join the ipv6-users JISCmail list if you want to discuss what happens on that list.

It’s thus timely to revitalise the www.ipv6.ac.uk web site with, at least initially, useful information for World IPv6 Day. As June 8th comes closer, we’ll provide more info here on relevant news to sites within the UK academic community.

Today has brought some interesting news. Google Chrome now includes code that will ensure fast fallback to IPv4 if the browser is experiencing IPv6 connectivity problems. A blog post mentions the addition of the feature in the browser and more specific details can be found at the foot of this code note. This means Google’s own browser can perform well for Google users having any problems on the day.

The RIPE NCC has also released its IPv6 Eye Chart which is a web page that performs a set of connectivity tests to dual-stack servers with ‘at a glance’ results. It’s thus a dual-stack test rather than an IPv6 test, but sites will show ‘green’ if they’re reachable over IPv4 or IPv6 within 10 seconds, i.e. if turning on IPv6 at the provider doesn’t break your existing IPv4 connectivity.

It’s worth noting the IPv6 Day is 0:00 to 23:59 UTC on June 8th, so while the UK is asleep, the effects of the ‘test flight’ of IPv6 will be first experienced elsewhere in the world. It will be interesting to see what reported experiences we wake up to on the morning.