Navigating from IPv4 to IPv6

The available supply of IPv4 addresses (that were not distributed to users) was exhausted over ten years ago. In anticipation of that exhaustion a new protocol was developed: IPv6. This version of the networking essential is formatted to provide nearly infinite supply and at no cost. No cost, that is, to acquire them. Implementation is another matter. Still, adoption of IPv6 has been slow, with the older format retaining about half the current levels of use, worldwide.

Markets for IPv4 addresses have been developed and large numbers of these addresses move from unused holders of them to new owners who are in need of them. About 40 million IPv4 addresses are bought and sold every year, plus many more change hands in transfers involved in mergers and acquisitions.

Because these assets are far from free, businesses and organizations that rely on IPv4 addresses use technologies to extend the usefulness of them. Carrier grade Network Address Translation (CG-NAT, CGN, or just NAT) is deployed to extend the utility of the IPv4 addresses they have. Of course, these technologies have their limits and costs.

Many organizations use private IPv4 addressing. This allows the same address to be  used in multiple private (walled-off) environments. But even this isn’t adequate in very large networks. Mobile carriers, cloud providers, and worldwide user-base platforms like Facebook and LinkedIn have migrated to IPv6 internally because it provides flexibility, better performance, and cost savings.

Any organization when considering either an internal or external network (or both) that are growing should consider migrating to IPv6.

That said, the question revolving around nearly-complete IPv6 transition is a matter of when, not if. From this comes the next obvious question: how? Luckily, one doesn’t have to be a pioneer to succeed in this. Methods have been developed and there is a log of experience is process-design to help.

With a structured approach, the transition to IPv6 isn’t a herculean effort. The key is having a clear plan in place—ensuring long-term growth and compatibility as the internet landscape evolves.

Transition or Add?

A dual-stack IP model, or dual-stack networking, describes a network configuration both IPv4 and IPv6 protocols are supported. In a dual-stack environment, devices and servers simultaneously support both, allowing for communication among devices using either protocol. 

For almost all networks contemplating use of IPv6, a dual-stack approach is likely. This allows for a gradual addition of IPv6 monitoring and use, allowing networks time to test and repair as the transition occurs. An entirely new network might contemplate an IPv6-only environment, but transitioning all at once introduces a lot of peril.

The Case for IPv6

Note that IPv4 continues to function as designed. It is in wide demand and important for public-facing organizations that may have users relying solely on it. But there are circumstances where “currently adequate” isn’t ideal and may not be nearly enough.

For example, the cloud has moved use elsewhere for many companies. Those using managed service providers (MSPs) may only need a small block of external IPv4 addresses in any one facility. However, the key factor is their use of cloud resources.

Cloud providers, like Amazon and Azure, charge for leasing IPv4 addresses. Often by the hour and usually about half a cent per hour per address. For those with heavy cloud use, these costs can rise quickly and substantially. In fact, the burden of these costs has led to increased purchaser demand for IPv4 addresses as the outlay for acquiring them. But these costs are relatively high, either way.

The stopgap of private address space can also develop usability problems. This frequently happens when two entities merge, either through acquisition or some other device. When this occurs the private address space of each frequently overlap. Both companies discover they are using the same private address space, leading to address conflicts when integrating networks.

Network expansion is also a reason to consider IPv6. As networks grow organically, they often become difficult to manage. Inefficiencies develop. To support growth, it’s best to design an IPv6-based network from the ground up – one that is more streamlined, scalable and capable of accommodating growth plans.

How to Plan IPv6 Adoption

Transitioning to IPv6 isn’t quick, but it’s also not as daunting as one might think. The key to successful addition of IPv6 to an existing network or moving to complete adoption in an IPv6-only environment is to follow a well-tested process:

• Audit Your Network – Start by discovering exactly what you have and whether it can support IPv6. This includes compatibility checks including hardware, software and partner organizations. This can be a tedious, time-consuming step and so best begun early rather than when urgent needs arise.
• Develop a Transition Strategy – Plan your transition strategy server by server. Include whatever systems, IPAM and otherwise, you will use to monitor both IPv4 and IPv6.
• Train Your Team – IPv6 isn’t utterly different from IPv4. But there are subtle difference between them your network engineers will need to understand.
• Work with Your ISP and Cloud Providers – Find out what your ISP and cloud providers support before migrating. Getting IPv6 addresses from your service provider or regional internet registry is almost always a fast and simple process. Some ISPs don’t offer IPv6, though that’s no longer common.
• Implement and Monitor Gradually – The process can proceed in stages. For instance, begin by enabling IPv6 on external-facing services like websites and email. Once you’ve had experience with that transition, move to internal systems. Monitor performance, fix issues, and expand from there.

The Business Impact

IPv6 adoption has obvious cost benefits. It can drive business growth and improve performance. IPv6 is often a bit faster than IPv4 because some mobile networks optimize for it.

What’s Next?

Organizations should understand their the long-term costs of growing while depending solely on IPv4. There is also the consideration of the technical requirements of maintaining an IPv4 network versus migrating to IPv6. The key is making a careful, informed decision. Develop a plan for transitioning now, preparing for the future, or optimizing an existing IPv4 strategy to meet business needs over time.