This might be an issue as soon as 2010, John Curran, chairman of the American Registry for Internet Numbers, said in an interview with Computer Business Review.
The IPv4 address pool is about 81% depleted, and remaining addresses are being snapped up faster and faster as more individuals and more types of devices come online.
The international explosion in internet use over the last few years has been pulling IP address space from the available reserves at an increasing pace, meaning predictions about when it will run out, which have varied wildly in the past, have started to come to a consensus.
When you look at a group of forecasts, they’re all moving closer and closer, converging, Curran said. We had a 15-year window at one point, and now that window has estimates ranging from 2009 to 2012. It’s definitely soon enough that we can call the game now.
ARIN is one of five Regional Internet Registries, each responsible for allocating address space to ISPs and large organizations in one geographical area. These RIRs take blocks of IP addresses from the Internet Assigned Numbers Authority and give them to ISPs based on need.
Curran said the forthcoming IPv4 drought is not confined to ARIN’s North American region. The other RIRs in other parts of the world also acknowledge the problem and may take similar steps to ARIN, he said.
There are 4.3 billion possible addresses under the IPv4 specification, which is 32-bit. The IPv6 spec creates a 128-bit address space, meaning the number of possible addresses is exponentially more.
IPv6 allows for 340,282,366,920,938,463,463,374,607,431,768,211,456 addresses.
We could assign a million IP addresses to every grain of sand on Earth, and still have plenty left over. Excluding the possibility of ubiquitous internet-connected nanotech robots, it’s probably more than humanity will ever need.
When we move to IPv6, the addresses are large enough that we never have to do this again, Curran said.
One minor problem, he acknowledged, is that it’s difficult for a human mind to easily commit an IPv6 address to memory. Whereas an IPv4 address is written in base-10 notation, such as 127.0.0.1, an IPv6 address uses base-16 notation, hexadecimal, so it looks like this: 2001:fecd:ba23:cd1f:dcb1:1010:9234:4088.
The move to IPv6 will not be without its challenges, but the spec is has been under development for over 10 years, is already implemented in a broad range of software and hardware, and can be run alongside IPv4 for as long as is needed.
A lot of organizations already have IPv6 trials underway, Curran said. But there’s a huge difference between being able to make one or two sessions in a lab work and being able to roll out a service.
ARIN is encouraging all organizations that think they may need to request IP addresses from ARIN in the next few years to ramp up their IPv6 rollouts, as IPv4 addresses may not be available for much longer.
The organization resolved at a meeting earlier this month to take any and all measures necessary to assure veracity of applications to ARIN for IPv4 numbering resources.
This means that anybody reading this article and thinking they should stock up on IPv4 blocks now, to beat the rush, will likely find their application scrutinized for true need more closely than before.
ARIN also resolved to consider Internet Numbering Resource Policy changes advisable to encourage migration to IPv6 numbering resources where possible.
For example, Curran said, policies could be changed so that if an organization applied for enough IPv4 space to get it through the next 12 months, it might only receive enough to last 6 months, if the shortage of IP space was critical enough.
Curran said that IP address reclamation initiatives have been somewhat successful, but that they are not enough to usefully extend IPv4’s life expectancy.
Before the creation of the web popularized the internet, IANA handed out huge chunks of IP address space to organizations that could not possibly need so many. Companies including HP, Apple, Ford and General Electric, for example, were each assigned blocks of 16 million addresses in the early 1990s.
Organizations have been given the opportunity to turn in larger blocks that they simply don’t need and will never need and receive smaller blocks in exchange, Curran said. Some organizations have allowed the number authorities to reclaim address space in this way, he said.
Whether additional reclamation happens or not, it may only make a difference of months before IPv4’s pool expires, he added.
The imminent transition to IPv6 is inevitable, and it appears that the next few years will be the critical turning point for most of the internet. Every internet user will be affected to a greater or lesser extent.
For application developers, the transition to IPv6 should not be too difficult. Most software uses DNS to find online services, rather than hard-coded IP addresses, which eases the transition.
For smaller businesses, the sizes of organization Curran calls leaves on the branches of the internet, Network Address Translation could be enough to keep handing out LAN addresses for some time, although the move to IPv6 would eventually become a necessity.
The reality is that everybody should be looking at this issue, Curran said. We’re not in a crisis situation right now, but we are calling for deliberate action so we don’t get into that crisis situation.
