Apple’s latest “i” hit over a million sales in the first 28 days it was available. Combine that with sales of other Internet-abled devices like the iPhone, Android, Blackberry, and other “smart” phones as well as the continued growth of Internet users in general (via cable and other broadband access technologies) and we are heading toward the impending cataclysm that is IPv4 address depletion. Sound like hyperbole?

It shouldn’t. The depletion of IPv4 addresses is imminent, and growing closer every day, and it is that depletion that will cause a breakdown in the ability of consumers to access the myriad services offered via the Internet, many of which they have come to rely upon. The more consumers, the more devices, the more endpoints just exacerbates the slide toward what will be, if we aren’t careful, a falling out between IPv6-only consumers and IPv4-only producers and vice-versa that will cause a breakdown in communication that essentially can only be called “Internet Armageddon.”

Even if you – either individually or as an organization - have enough IPv4 addresses, providers don’t. Combined with the explosion of devices and clients on the consumer end of the spectrum that may well cause a problem for you, at least if you rely on users (and most of us do). If providers are forced to move to IPv6, how are those clients going to talk to you (and others) still living in IPv4 land?

Mel Beckman of InfoWorld warns of the dangers in the rising black market for IPv4 addresses and failure to adopt IPv6 sooner rather than later:

Organizations slow to adopt IPv6 take heed: Surging requests for IPv4 addresses are quickly drying up the available store, raising the specter of an IPv4 black market that could dramatically increase the cost of obtaining a presence on today's Internet.

…

As of this writing, only 20 IPv4 /8s remain in the Internet Assigned Numbers Authority (IANA) pool of 256 /8s. At the current rate, the IANA pool may well be exhausted by the end of this year (see graph). And though the transition from IPv4 to IPv6 has been long anticipated, many organizations are ill-prepared for the fallout of IPv4 exhaustion. In addition to being required to maintain Web presence in both address spaces until the Internet's transition is complete, new services, such as Microsoft's DirectAccess, are increasingly becoming available only on IPv6, as tech vendors and service providers increasingly find IPv4 too expensive to support.

An April 2010 report from OECD (Organisation for Economic Co-operation and Development) “Internet Addressing: Measuring Deployment of IPv6” explains in part why it’s so hard to get providers and other large consumers of IPv4 address blocks to move to IPv6:

When IPv4 addresses are fully allocated, operators and service providers must support the newer version of the Internet Protocol (IPv6) in order to add additional customers or devices to their networks. Otherwise, they will need to employ complex and expensive layers of network address translation (NAT) to share scarce IPv4 addresses among multiple users and devices.

Imagine, if you will, that providers continue to ignore the need to support IPv6. Imagine that you need to share a single IPv4 address with fifty or sixty of your neighbors. Once IPv4 addresses are depleted providers could either adopt the practice of oversubscribing their networks (many already do, assuming their full customer base won’t be online at the same time) in the manner of airlines or, as suggested, implement expensive and highly disruptive infrastructure overlays to support a private IPv4 network for its consumer base while using its available public IPv4 addresses to communicate and route across the Internet. Or it could just pony up the cash and replace everything – everything – with IPv6 capable solutions.

In mobile device land the problem is different, but causes the same issues with IP address allocation. Mobile devices generally access the Internet via gateways that already provide address translation (private to public) services, but the underlying infrastructure can only handle so many devices at one time, lest its performance degrade to the point of unusable or begins to lose data. That means additional IP address blocks (and the supporting infrastructure) are necessary to keep service at an acceptable level. 

Simply implementing IPv6 isn’t necessarily a panacea, either, as IPv4 can’t talk directly to IPv6 and vice-versa.

The reason this should be of concern to everyone – network and systems’ administrators, developers, startups, large organizations, and providers – is because once we go IPv6 on the consumer side (and we will, have no doubt) we can’t really go back. That means customers will be talking IPv6 and you’ll be talking… IPv4. Exactly. Even if it’s only mobile consumers at first, still – are you going to ignore the increasingly tied-to-their-electronic-leash millennial generation and their disposable income? The ones who’ve bought into Steve Jobs and Apple and the i(insert name of product here) to keep them connected to the Internet and consuming services 24/7 like some sort of all night free (as in gratis) buffet? 

Perhaps providers and organizations, increasingly made nervous (and well they should be) by the depletion of IPV4 addresses, could take an intermediate, less disruptive and certainly less expensive option: the IPv6 gateway. An IPv6 gateway is exactly what it sounds like; it sits between an existing IPv4-based infrastructure and translates between IPv6 on the outside and IPv4 on the inside, allowing organizations to support IPv6 consumers without requiring expensive fork-lift network upgrades and the disruption that entails.

Interestingly enough, it may be that the next “upgrade cycle” in network infrastructure (occurring every 2-3 years) will enable initiatives to support IPv6, whether via an intermediate gateway step or a full fork-lift upgrade. It makes sense that if you’re going to outlay a huge capital investment in upgrades anyway that you require support for IPv6 and go ahead and take the plunge then rather than before those guys in accounting want you to. This is not unlike the advice offered by Jonathan Feldman, CIO of the City of Ashville, NC (and frequent contributor to Network Computing magazine) at Interop last week to wait for the organizational upgrade cycle before moving to cloud. It makes sense that any significant move in technology, whether toward cloud computing or to support IPV6, be undertaken at a time when capital expenditures are normally expected and budgeted for and can be used to support an initiatives requiring an investment in infrastructure.

It is in no small part the explosion of mobile devices like the iPad that is driving the depletion of IPv4 addresses at an increased rate. Unless we make the move to IPv6 – and soon – we will eventually hit a point at which consumers are no longer able to assume connectivity with every site on the Internet, which will mean it’s time to start it calling the “Maybenet” instead, as interoperability at the IP layer is what has driven the Internet forward. A lack of interoperability at that layer, as would occur with the inability to communicate between IPv4 and IPv6, would certainly destroy the Internet as we know it.