Further to our news item last month, a number of very high profile websites will enable IPv6 for the duration of June 8th. Most end users are unlikely to be affected negatively, but there are users that have misconfigured setups that will be triggered by this change.

The size of the problem is small in aggregate, but we have received feedback that aggregates, while reassuring, can be potentially misleading. While the fraction of impacted users in the world is expected to be less than 1 per cent, the incidence on an affected network could be considerably higher (or it could affect particular crucial machines.)  In particular, Apple Mac computers running a less-than-current version of the operating system are known to show problems in some cases.

Our NOC, of course, will be happy to help where we can and will be contactable as usual at noc@heanet.ie and 01-6609040.

Following June 8th, we would be very grateful to hear from all our clients about their experience, good and bad, of World IPv6 day. We will collate this information and may provide an anonymous summary to help prepare for future such events.  In the meantime, we have these additions to the previous advice:

The two main causes of the problem are:

• incorrectly configured machines on an IPv4 only network, or
• an incorrectly configured IPv6 network

In the case of a misconfigured machine, the test must be run on the user's machine, and the incorrect configuration reversed. It should not be necessary to disable IPv6, as it is likely that there is an incorrectly configured tunnel set up on the machine.

In the case of a misconfigured IPv6 network, the problem is solved by restoring full IPv6 access.

RIPE NCC have developed an easy-to-use test site to help determine if you are likely to have problems on IPv6 day itself: http://ipv6eyechart.ripe.net/

The ARIN IPv6 Wiki has extensively collected solutions to the most common problems that can occur: http://www.getipv6.info/index.php/Customer_problems_that_could_occur

And the World IPv6 day site itself is now at http://worldipv6day.org/