Vint Cerf, also known as the father of the Internet, warned that we'd run out of IP addresses by 2010. That didn't happen. Now some pundits are predicting 2012 as the new doom-and-gloom date for the World Wide Web.
No one knows for sure when the original pool of IP addresses will be depleted, but one thing is certain: The continued growth of the Internet and the increasing use of machine-to-machine communications makes it likely -- and soon.
Here's how it works in a nutshell: IP version 4, or IPv4, addresses are allocated by the Internet Assigned Numbers Authority (IANA) to regional registries. The registries then allocate IPv4 addresses to individual customers. As it stands, the last free pool at IANA is tracking for September 2011 -- and the last address would be offered to an individual customer about a year later, or about 700 days from now.
"As with all scarce resources, occupation of new address resources will slow down as the free pool shrinks, just as oil consumption decreases as the price goes up," said Dr. Milton Mueller, a professor at the Syracuse University School Of Information Studies' Internet Governance Project. "But sooner or later, the free pool will be gone. IPv4 addresses are fixed in number and most of them have already been handed out to organizations and ISPs."
Exhausting the Pool
Several factors contribute to address scarcity. First, the Internet address space is a fixed quantity, set by the basic Internet protocol standard of 1981. It allows for about four billion unique bit combinations. In the early years of Internet development, address blocks were handed out too easily, Mueller said, because no one knew the Internet would become so large. By 1993, about 40 percent of the addresses had already been given out.
"The regional address registries don't have effective reclamation policies, so once they give out an address block, it never comes back, regardless of how efficiently it is used," Mueller said. "A more fundamental cause of inefficient address usage is the need for aggregation of routes. This is difficult to explain simply, but the current system of routing makes it difficult and sometimes impossible for users to carve up their address blocks into smaller pieces and move them around to different users, so there is a lot of underutilized address space."
What happens when we run out of IPv4 addresses? The impact of an IPv4 address exhaust can manifest itself in a number of ways -- technical and business, according to Pravin Mahajan, marketing manager for Cisco's Core Solutions. There's a possibility of a 'last-chance' rush on the registries, he said, along with industry talk about the possibility of trading IPv4 addresses. However no such model exists today or is forecast to be built. (continued...)