All too often, IPv6 is simply ignored or postponed to make room for seemingly more important things. However, IPv6 is one of the most important topics for the future of IT. The transition to IPv6 is a company-wide project. It is not enough for the IT department to have a brainstorming session and hatch a plan. Everyone who has a legitimate interest in the actions and their results must be involved. IPv6 migration planning must be a top priority, and it must have the support of management.

The Right Perspective

If you are responsible for project planning, you need to think like a general: Do not just consider the individual areas of the battlefield but analyze the overall situation. Gain insights, identify strengths and weaknesses, and define objectives. Only after this process should you start to develop a plan for how and in what order you will achieve these objectives. Defining these milestones has proved essential to IPv6 migration.

Always schedule sufficient time and take setbacks into account. Depending on the environment, an IPv6 migration could extend over several years, so be realistic and not too optimistic. You will put yourself and your team under unnecessary management pressure if you define the timing goals too tightly.

Establishing experience and know-how is an important part of the IPv6 migration. Build a lab environment that simulates the basic components of the production environment and allows for realistic testing. If you need to roll back and restart because of a lack of testing, your users will not be happy – not to mention the potentially unpleasant questions from management. Be sure to perform extensive testing on the results after each change.

While you are planning your project, you need a realistic assessment of the costs. Costs arise from the need to replace non-IPv6-capable systems, but also from person-days, expenses for employee training, and support by external service providers.

Evaluation of the Situation

A sensible first step in migration planning is to make an inventory of the existing IT systems. In the best case, you will have a well-maintained, up-to-date Configuration Management Database (CMDB). In addition to other information, your list should include the following data for each asset (e.g., computer, printer, switch, software):

• Item name
• Description of function
• Software version
• Responsible employee/department/organization
• IPv6-readiness: unrestricted, restricted, no IPv6 capability
• Importance of the system in case of failure – on a scale from 0 to 5

It is also of utmost importance to determine the mutual dependencies of the components. For example, leaving an important file server inaccessible during the migration can affect many parts of the IT infrastructure.

After completing the inventory, you need to identify which components are IPv6 capable. Not all systems and subsystems of an IT infrastructure are relevant to the IPv6 migration. For example, you will not be interested in the desktop or server housings or other passive components. All components that communicate via IP(v4) are initially involved, including printers, switches (at management level), NTP server systems (hardware-based), card reader systems, and IP phones.

You'll need to test all of these systems for their IPv6 capability. However, you should not assume that IPv6 is in place just because it says so on the box: often IPv6 support is only available for a subset of the features and can be buggy. The goal of the laboratory tests is to uncover these kinds of problems. Components that are not IPv6-ready fall into two categories:

• Systems that can be made IPv6-enabled by upgrading
• Systems that cannot be made IPv6 capable because of their age or design

You'll need an appropriate budget and schedule for upgrading everything you can upgrade. Any systems you can't upgrade you'll need to replace or eliminate – or come up with a plan for how you will isolate them and keep them running on IPv4, possibly using translation mechanisms such as NAT64 to connect with the IPv6 network.

Involving Service Providers

Internet and intersite connections are typically managed through service providers. Many providers offer advanced IPv6 migration options; however, it is important to contact your service provider and clarify the possibilities.