Chapter 5. IPv6 Address Planning Concepts

Practice safe design: use a concept.

— Petrula Vrontikis


It’s been said that design is where science and art break even. In this chapter, we’ll focus primarily on the science part of IPv6 address planning and be as thorough as we can be with the design concepts and principles that you’ll need to be familiar with to tackle your plan. As we proceed, however, we’ll be sure to consider the art of address plan design as well, an art based on accumulated operational knowledge and practical experience and the best-practices that have evolved from it.

IPv6 Address Planning Principles

We’ve already mentioned earlier that IPv6 address planning should not be based on (e.g., sufficient host addressing).

But given that, what should it be based on (and why)? Let’s examine the fundamental IPv6 address planning principles in brief before looking at each more closely. They are:

Properly sized initial allocations
This is arguably the most critical of all the address planning principles we’ll discuss. The reason is that all of the principles that follow are more or less dependent on getting a sufficiently large allocation at the start.
Sparse assignment of subnets
With a sufficiently sized allocation, we’ll be able to assign subnets sparsely, i.e., leave unused space between our assigned subnets adequate for future growth or network reconfiguration.
Hierarchical organization of subnets
A sufficiently sized allocation also allows ...

Get IPv6 Address Planning now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.