I was recently working on a project involving readiness for IPv6, and during the course of the research, one thing jumped out. Almost nobody is actually ready for IPv6, despite the impending IPv4 address exhaustion due nearly any time now. Depending on who you ask, the number of organizations actually ready to operate in an IPv6 environment is somewhere under 10 percent of everyone on the Internet. This means that hardly anyone is ready for the day when they can't get more IPv4 address allocations. It's hard to say what will happen then, but it probably isn't good.
Fortunately, it is possible to determine whether you're completely ready for IPv6. The Tennessee Technology Center at Shelbyville has published an IPv6 assessment tool that you can access over the Internet. All you have to do is browse to their site, and you'll learn as I did that you're not ready.
Unfortunately, the TTC doesn't tell you why you're not ready, it just tells you whether you are. However, figuring out why you're not ready isn't exactly rocket science for most users and most IT shops. The TTC will give you a list of what to look for on the same page as its validation tool. In general, you need three things to make IPv6 work. These include an IPv6-capable operating system, infrastructure that supports IPv6, and a pathway to the Internet that supports it.
The chances are pretty good that your computer operating system supports IPv6 and may even have it turned on. Recent versions of Windows and Linux, for example, come with IPv6 enabled. Likewise, most recent network infrastructure supports IPv6, but it may need to be turned on. Unfortunately, some companies may keep their routers and switches for a very long time, and then not update them. These may not support IPv6.
Likewise, DNS and DHCP servers in your data center may not support IPv6 even if the rest of your hardware does. You may need to replace these items, or you may need a software upgrade. However, companies using recent versions of Windows and Linux servers may be able to configure those servers to provide IPv6 support as well.
If there's a weak link in the world of IPv6, it's the access to the Internet. Many ISPs, including Cox Communications, the ISP that services me, aren't ready. I may be able to run IPv6 inside my own network, but I can't use it to reach the outside world. This is not an uncommon problem, but on the other hand, it may eliminate any immediate need to change to IPv6-many ISPs use private addressing systems that never see the outside world. Those ISPs may never need to convert their users to IPv6, but it may mean that over time, users on those networks may not have full access to the Internet, and the Internet may not have full access to their websites.
Over time, use of IPv6 will become increasingly important for access to the full Internet, but IPv4 won't simply disappear. For a while at least, companies will need to maintain parallel addressing, so that the devices on their networks that need access to the outside world can do it with both IPv6 and IPv4. With the right infrastructure, this should be something you can handle automatically.
But if you can, this is something that needs to be tested. IPv6 isn't necessarily implemented successfully on all platforms, so you need to make sure that you find out sooner rather than later how your network stacks up.