Let's review IPv6-related features of Vista
At the end of January 2007, Windows Vista will make a debut at last. As we have reported so many times, the biggest feature of Vista networking is "IPv6 native support". This does not only mean that Vista's IP stack will be IPv6 by default, but it also means that IPv6 support by all included applications has become Microsoft's development goal.
Existing Windows XP also supported IPv6 as an OS, and several applications supported IPv6. But the support was not given by default. Therefore people often had difficulties in actual usage situations, not being able to use all IPv6 features, or with incomplete support by applications.
But with Vista, IPv6 support is given from the beginning, from Web browser, mail client, to various tools, under the name of "comprehensive IPv6 support". In this article, we will introduce you to a new an easy way to get along with IPv6, using IPv6-native OS Windows Vista.
Difference between Vista and XP
Before we get into actual use of Vista and IPv6, let's confirm the difference between existing Windows and Vista.
The first IPv6 application on Windows XP that comes to mind is Internet Explorer. It is the easiest to see IPv6 Web site to confirm that you are connected to the Internet with IPv6. That's why the tool stands out. It is natural for the people who got access to IPv6 environment for the first time to want to see dancing kame (tortoise).
But constantly using the Internet is not the same as net surfing. Without doubt, communication tools such as mail and messenger is important. There are millions of other applications that use networking. But Outlook Express and Windows Messenger, standard-equipped applications on Windows XP, did not support IPv6.
In fact, mail server itself (Exchange Server) supported IPv6 for some time now, but the mail client with the best market share has not supported IPv6. Therefore it has been difficult to deploy IPv6 in offices and other places.
In addition, Windows XP had a problem of not being able to operate IPv6-only environment. The OS supported IPv6, but the support was based on dual stack with IPv4. In reality, given the current Internet, office network should become IPv4/IPv6 dual network, not IPv6-only.
Therefore, on the first look, the situation doesn't seem to have changed very much with XP. You could use third-party or open source mail client software with XP with no problem. With messenger, you could at least use IPv6 on the Internet with patches or port forwarder, if the packet payload was IPv4.
Then what is the advantage of Vista in using IPv6, in other words, what were lacking in XP?
Changes with Vista
There are so many advantages of Vista in using IPv6. Technically, much of it is related to the use of DNS.
It is not unusual to specify addresses such as 210.xxx.yyy.zzz, in accessing Web site on the Internet with IPv4, when DNS is not available, even when it is not for testing purposes. But you can see immediately you can't do that with IPv6. In other words, DNS is indispensable in using IPv6.
For example, when you query the address of the site www.sample.com to a DNS server, you get AAAA record as response if the server supports IPv6. If www.sample.com has IPv4 address, you get A record response. If the site has both IPv4 and IPv6 addresses, you get two responses.
With XP, there are two problems in this process. One is that you can only use IPv4 to make queries to DNS servers. Even if all environments are designed with IPv6, you have to use IPv4 for DNS. This issue, however, can be said to be a minor one (in that IPv6-only environment is hard to consider in reality).
The second issue is serious. This occurs when destination host or site has both IPv4 and IPv6 addresses. With XP, AAAA record is supposed to be given priority, but A record is sometimes used instead. This is described in Microsoft KB but it sometimes can't be avoided as it involves DNS server issue. People cannot use the environment comfortably.
One of the possible solutions is to operate DNS server on IPv6 also, making it return AAAA record only if AAAA record is available, in response to request from IPv6 address. Of course, it goes without saying that it should return A record only if just A record is available. The reason this can be a solution is that sending requests on IPv6 assures IPv6 access. If request is made on IPv4, DNS can't make a decision even with IPv6 connectivity.
In addition, with current application implementation, it has to be aware of the availability of AAAA record and A record. If either of them is not available for some reason, application itself has to make a switch as protocol stack does not have such a feature. And even if this solution is adopted, clients have to be able to send DNS queries on IPv6, which was not possible with XP.
Another thing XP was lacking with IPv6 is that IPSec support was not mature. IPSec without data encryption was not of much use anyway. Vista offers usable level functionality, if not full features.
In addition, Vista's firewall supports IPv6. XP firewall supported IPv6 but was not very easy to use, because of command line interface. With Vista, IPv6 setting can be made in the same way as IPv4. In terms of features, the new firewall is not a mere packet filters but a stateful one. The firewall has become something that is suitable for IPv6, which will be increasingly be used for direct, peer-to-peer connections.
Vista's breakthrough
But the advantage of using IPv6 with Vista is not just that Vista IPv6 features work as the spec says. It makes it easy to utilize networking in a certain way which has been difficult so far.
For example, you can connect a PC in your office and your PC at home with IPSec for file sharing, accessing materials you worked on at home from your office. Or you can create an ad-hoc network with IPv6 and Wi-Fi at meetings at clients for sharing data and desktops using Windows Meeting Space. Or you can create a secure communication environment by shutting down all communications other than IPSec. Vista and IPv6 makes all of these easier than before.
Thus, Vista has the potential to lift up IPv6 from barely usable to plain usable level. In the following articles, we will actually try out some of the features, to show that IPv6 is plain usable. We hope the readers to feel that everyday work routines can be "more convenient and easier" by knowing that IPv6 can be used with no toil and can be combined with Vista's various new features.
