– Lori MacVittie, senior technical marketing manager at F5 Networks (www.f5.com), says:

IPv6 Integration with partners, suppliers and cloud providers will make migration to IPv6 even more challenging than we might think…

My father was in the construction business most of the time I was growing up. He used to joke with us when we were small that there was a single nail in every house that – if removed – would bring down the entire building.

Now that’s not true in construction, of course, but when the analogy is applied to IPv6 it may be more true than we’d like to think, especially when that nail is named “integration”.

Most of the buzz around IPv6 thus far has been about the network; it’s been focused on getting routers, switches and application delivery network components supporting the standard in ways that make it possible to migrate to IPv6 while maintaining support for IPv4 because, well, we aren’t going to turn the Internet off for a day in order to flip from IPv4 to IPv6. Not many discussions have asked the very important question: “Are your applications ready for IPv6?” It’s been ignored so long that many, likely, are not even sure about what that might mean let alone what they need to do to ready their applications for IPv6.

The bulk of issues that will need to be addressed in the realm of applications when the inevitable migration takes off is in integration. This will be particularly true for applications integrating with cloud computing services. Whether the integration is at the network level – i.e. cloud bursting – or at the application layer – i.e. integration with SaaS such as Salesforce.com or through PaaS services – once a major point of integration migrates it will likely cause a chain reaction, forcing enterprises to migrate whether they’re ready or not. Consider for example, that cloud bursting, assumes a single, shared application “package” that can be pushed into a cloud computing environment as a means to increase capacity. If – when – a cloud computing provider decides to migrate to IPv6 this process could become a lot more complicated than it is today. Suddenly the “package” that assumed IPv4 internal to the corporate data center must assume IPv6 internal to the cloud computing provider. Reconfiguration of the OS, platform and even application layer becomes necessary for a successful migration.

Enterprises reliant on SaaS for productivity and business applications will likely be first to experience the teetering of the house of (integration) cards.

“Enterprises are moving to the cloud, according to Yankee Group’s 2011 US FastView: Cloud Computing Survey. Approximately 48 percent of the respondents said remote/mobile user connectivity is driving the enterprises to deploy software as a service. This is significant as there is a 92 percent increase over 2010. Around 38 percent of enterprises project the deployment of over half of their software applications on a cloud platform within three years compared to 11 percent today, Yankee Group said in its “2011 Fast View Survey: Cloud Computing Motivations Evolve to Mobility and Productivity.” — Enterprise SaaS Adoption Almost Doubles in 2011: Yankee Group Survey.

Enterprise don’t just adopt SaaS and cloud services, they integrate them. Data stored in cloud-hosted software is invaluable to business decision makers but first must be loaded – integrated – into the enterprise-deployed systems responsible for assisting in analysis of that data. Secondary integration is also often required to enable business processes to flow naturally between on- and off-premise deployed systems. It is that integration that will likely first be hit by a migration on either side of the equation. If the enterprise moves first, they must address the challenge of integrating two systems that speak incompatible network protocol versions. Gateways and dual-stack strategies – even potentially translators – will be necessary to enable a smooth transition regardless of who blinks first in the migratory journey toward IPv6 deployment.

Even that may not be enough. Peruse RFC 4038, “Application Aspects of IPv6 Transition”, and you’ll find a good number of issues that are going to be as knots in wood to a nail including DNS, conversion functions between hostnames and IP addresses (implying underlying changes to development frameworks that would certainly need to be replicated in PaaS environments which, according to a recent report from Gartner, indicates a 267% increase in inquiries regarding PaaS this year alone), and storage of IP addresses – whether for user identification, access policies or integration purposes.

Integration is the magic nail; the one item on the migratory checklist that is likely to make or break the success of IPv6 migration. It’s also likely to be the “thing” that forces organizations to move faster. As partners, sources and other integrated systems make the move it may cause applications to become incompatible. If one environment chooses an all or nothing strategy to migration, its integrated partners may be left with no option but to migrate and support IPv6 on a timeline not their own.

While the answer for IPv6 migration is generally accepted to be found in a dual-stack approach, the same cannot be said for Intercloud application mobility. There’s no “dual stack” in which services aren’t tightly coupled to IP address, regardless of version, and no way currently to depict an architecture without relying heavily on topological concepts such as IP. Cloud computing – whether IaaS or PaaS or SaaS – is currently entrenched in a management and deployment system that tightly couples IP addresses to services. Integration relying upon those services, then, becomes heavily reliant on IP addresses and by extension IP, making migration a serious challenge for providers if they intend to manage both IPv4 and IPv6 customers at the same time. But eventually, they’ll have to do it. Some have likened the IPv4 –> IPv6 transition as the network’s “Y2K”. That’s probably apposite but incomplete. The transition will also be as challenging for the application layers as it will for the network, and even more so for the providers caught between two versions of a protocol upon which so many integrations and services rely. Unlike Y2K we have no deadline pushing us to transition, which means someone is going to have to be the one to pull the magic nail out of the IPv4 house and force a rebuilding using IPv6. That someone may end up being a cloud computing provider as they are likely to have not only the impetus to do so to support their growing base of customers, but the reach and influence to make the transition an imperative for everyone else.

IPv6 has been treated as primarily a network concern, but because applications rely on the network and communication between IPv4 and IPv6 without the proper support is impossible, application owners will need to pay more attention to the network as the necessary migration begins – or potentially suffer undesirable interruption to services.