Enabling all the pieces for IPv6
If your clients use DHCP, your IPv6-enabled clients should have no trouble working with IPv6-enabled DHCP servers (running DHCPv6), assuming thery're all on IPv6-compatible OSes and have IPv6 turned on. However, you need to make sure your routers are ready for IPv6 and can play nice with it. That means you and your users may need to upgrade your networking hardware at home or in the office.
Of course, IPv4 isn't going away, even if there are no new IPv4 addresses to issue. Some hardware, including certain mobile clients, may not support IPv6, and you may not want to mess with reconfiguring users' home systems. That's why the major OSes and networking hardware support both protocols and can run them simultaneously. Note, though, that IPv4 and IPv6 are not compatible: IPv6 may work on the same wire as IPv4, but they don't talk to each other. Thus, expect to manage two sets of IP addresses for the foreseeable future, and don't be surprised to see implications for your security and access control settings.
You'll still use NAT (network address translation) to handle IP address mapping within your network for IPv4 addresses, but over time, as you move to IPv6, you'll find NAT is no longer needed as every device can have its own IPv6 address, which could change how you think about your network's logical topology and routing. If you haven't explored IPv6 yet, now is definitely the time.
Remember: Some organizations have already been through a similar transition. The Network Control Protocol (NCP) was the first Internet protocol, and it IPv4 ran concurrently with IPv4 until Jan. 1, 1983. Sure, that transition occurred on a much smaller scale -- the movie "War Games" wouldn't be released until June 1983, and the number of network devices in those early days of the PC was a tiny fraction of what it is today -- but the handoff ran fairly smoothly.
World IPv6 Day, scheduled for June 8, 2011, and sponsored by the Internet Society, will help you test and prepare, as Facebook, Google, Yahoo, and others will enable IPv6 so that people can test their IPv6 readiness in the real world. Check it out.
This article, "Get your Windows networks IPv6-ready -- while you still can," was originally published at InfoWorld.com. Read more of J. Peter Bruzzese's Enterprise Windows blog and follow the latest developments in Windows at InfoWorld.com. For the latest business technology news, follow InfoWorld.com on Twitter.