3) You can't simply flip the magic IPv6 switch and make the whole world IPv6 at once, so you'll need to make provisions to operate IPv4 and IPv6 side-by-side for the foreseeable future. Think of it as "indefinite coexistence."
Every good coach knows you can't win without a strategy, and transitioning to IPv6 requires a two-part strategy that will set the foundation for a successful rollout.
The first part of the strategy is itself divided into two phases:
Phase 1. Customer-facing content. Anything that is exposed to the Internet should be transitioned first. This is especially true for enterprises that rely on the Internet as a means of doing business. As time goes on, more and more IPv6-only clients will be popping up on the Internet as ISPs run out of IPv4 addresses. While any smart ISP will provide some sort of transition mechanism to ensure their IPv6 customers have the ability to access IPv4 content, you cannot rely on this as your only means of reaching those customers. If a particular ISP's transition mechanism doesn't work well with your content, who is the IPv6 customer going to blame? You of course! If your website fails to load properly or in a timely manner in the customer's browser, chances are he will get annoyed and move on to your competitor. Therefore you need to make a priority of getting your Internet-facing content onto the IPv6 Internet.
(As an aside, getting your content on IPv6 isn't as simple as just running dual-stack on your Web server. You most likely have an entire infrastructure that will need to transition prior to sending and receiving IPv6 packets on that server. We will discuss this more later.)
Phase 2. Internal systems. Once your customer-facing content is available to the IPv6 Internet, you can now direct your attention to internal systems. Internal system communications includes anything that doesn't typically leave your organizational boundary, such as system-to-system traffic and management traffic. This phase also includes internal client PCs.
This two-phased approach makes the transition more manageable and is similar to what all Federal agencies are doing (see this OMB mandate from September 2010). By focusing on customer-facing content first, you can ensure your organization won't lose visibility as more and more IPv6 users come online. The remaining steps in this article will ultimately be performed twice, once for each phase.
The second part of the strategy is really the linchpin of the entire framework: transition areas (TAs). This is where all transition-related activities take place, forming the foundation of your enterprise rollout.
The basic concept behind TAs is to break the enterprise into several functional categories. The exact number of areas may vary from one organization to another, but many will overlap. Some TAs are 100% technical, while others are more people and process oriented.
Here is a sample list of TAs that will apply to most enterprises. Your list may be bigger or smaller depending on your needs.
● communications infrastructure
● servers and operating systems
● IPv6 address space