There is something that people, such as network administrators and ISP engineers, need to pay attention to in preparation for Windows Vista being released near the end of 2006.
That 'something' is the fact that Windows Vista supports IPv6 by default. This means that when an end user purchases a computer with Windows Vista preinstalled and runs it for the first time, or when a user purchases Windows Vista and installs it on his/her computer, the computer already has its IPv6 stack enabled and if the user wants to, he/she can use that IPv6 stack as soon as he/she connects the computer to an IPv6-ready network.
The thing is that this may become a problem. It is not clear whether or not this will really be a big problem because this is the very first time a mass-market product, such as Windows, supports IPv6 by default.
Up until now, when adopting IPv6-ready products, in most cases only necessary devices were used, after carefully designing the network. In other words, those devices were used only in environments that needed them and by people who needed them. However, once Windows Vista is released, that may not be the case any more.
So, the IPv6 Promotion Council's Transition Working Group formed the "v6 OS Evaluation Sub-Working Group", which has been investigating and performing tests to see what could happen when not only Windows Vista, but also client and embedded OSs, support IPv6 by default.
The Transition WG held a general meeting in July and the v6 OS Evaluation SWG gave an interim report. According to this report, the SWG has just finished identifying the issues and they plan to announce those issues soon and call for opinions on them. Then, they will report the guidelines, which is a summary of those opinions, around November or December, before Windows Vista is released.
Not only are ISPs, network vendors and device manufacturers participating in this SWG, but Microsoft is participating as well. All the participants will work together in order to resolve any issues.
Then, what kind issues were identified by the SWG? One of them is that the number of DNS queries are double that of when only IPv4 is used.
In an IPv6 and IPv4 environment, applications first query using IPv6 and if the target domain does not have an IPv6 address, it then queries using IPv4.
Furthermore, for Internet Explorer, depending on the configuration, if the domain the user input cannot be resolved using IPv4, it considers it as a word and searches for it using a search engine. So long as DNS queries are necessary on the Internet, when Windows Vista is used in an IPv6 environment, it is very possible that the DNS's load will double.
At the SWG, they have also identified several other issues and continue to work on thoroughly identifying the problems that can occur in an IPv6-enabled OS.
However, client OSs are not the only place where problems could occur. With IPv6, each company that provides IP-based services can provide access to their private service network to each customer. That means that several companies could provide several different IPv6 addresses (prefixes) to one user site.
There has not been enough testing performed for running networks under such a multi-prefix environment. So, in addition to the v6 OS Evaluation SWG, the Transition WG formed the "Multi-Prefix SWG".
This SWG will examine and verify what could happen when running a network in a multi-prefix environment, and report the findings. It was officially formed at the Transition WG general meeting in July and is to give its final report in March 2007.
The release of Windows Vista is a boon for IPv6 propagation; however, it is also an issue that we need to deal with. Although problems can happen anywhere in the world, they are something that we will encounter here in Japan before anyone else since we use IPv6 the most. People around the world who would like Windows Vista to be a big stepping-stone for propagating IPv6 have high expectations for Japan.
