IPv4 Address Exhaustion Continues on Critical Path to Depletion

By October 20, 2010 Governance No Comments

The depletion of IPv4 addresses continues on its critical path with there now being only five per cent of the addresses remaining to be allocated, with the pool still set to be exhausted in mid-2011, despite an increasing take-up of IPv6 addresses. While the story is not new that the IPv4 address pool is becoming critically low, the slow take-up of IPv6 is of major concern given the approaching date for IPv4 exhaustion.

IPv4 depletion will impact the future network operations of all businesses and organisations around the globe with the Number Resource Organization (NRO) that allocates IP addresses becoming increasingly concerned. The NRO is warning all internet stakeholders to take definitive action now to ensure the timely adoption of IPv6 – the next generation of Internet Protocol – and the future interoperability of the Internet.

The reason for the situation arising where the IPv4 address pool is nearing exhaustion is Dr Vint Cerf’s fault the father of the internet told Federal Computer Week.

Cerf, now chief Internet evangelist at Google, came to Washington in 1976 as a programme manager at the Defense Department’s Advanced Research Projects Agency to help develop a new set of networking protocols, TCP/IP, for the experimental packet-switched network called the ARPAnet. One of the decisions his team needed to make was the size of the address space in the packets, the FCW report said.

Some researchers wanted a 128-bit space for the binary address, Cerf told an audience at a recent IPv6 workshop that the National Telecommunications and Information Agency hosted. But others said, “That’s crazy,” because it’s far larger than necessary, and they suggested a much smaller space. Cerf finally settled on a 32-bit space that was incorporated into IPv4 and provided a respectable 4.3 billion separate addresses.

“It’s enough to do an experiment,” he said. “The problem is the experiment never ended.”

Some 34 years later says FCW, those addresses are almost used up, and the 128-bit address is being adopted — large enough to provide an exponentially greater number of addresses. It’s a number so difficult for the mind to grasp that it typically is described in terms of grains of sand on a beach or golf balls filling the sun.

The Number Resource Organization (NRO) is the coordinating mechanism for the five Regional Internet Registries (RIRs). The RIRs — AfriNIC, APNIC, ARIN, LACNIC, and the RIPE NCC — ensure the fair and equitable distribution of Internet number resources (IPv6 and IPv4 addresses and Autonomous System (AS) numbers) in their respective regions.

With the announcement this week that less than five per cent of the world’s IPv4 addresses remaining unallocated, APNIC, the Regional Internet Registry for the Asia Pacific region, was assigned two blocks of IPv4 addresses by the Internet Assigned Numbers Authority (IANA). This latest allocation means that the IPv4 free pool dipped below 10% in January, just nine months ago. Since then, over 200 million IPv4 addresses have been allocated from IANA to the RIRs.

“This is a major milestone in the life of the Internet, and means that allocation of the last blocks of IPv4 to the RIRs is imminent,” states Axel Pawlik, Chairman of the NRO. “It is critical that all Internet stakeholders take definitive action now to ensure the timely adoption of IPv6.”

IPv6 is the “next generation” of the Internet Protocol, providing a hugely expanded address space, which will allow the Internet to grow into the future. In 2010, the five RIRs are expected to allocate over 2,000 IPv6 address blocks, representing an increase of over 70% on the number of IPv6 allocations in 2009. In contrast, the number of IPv4 allocations is expected to grow by only 8% in 2010. These statistics indicate an absence of any last minute “rush” on IPv4 addresses, and a strong momentum behind the adoption of IPv6.

“The allocation of Internet number resources by the five RIRs enables every region in the world to benefit from fair and equitable distribution of IPv4 and IPv6 addresses. We are also actively collaborating with stakeholders at the local, regional, and global level to offer training and advice to public and private sector organizations on IPv6 adoption to ensure that everyone is prepared for IPv4 depletion and IPv6 deployment,” added Pawlik.

The IANA assigns IPv4 addresses to the RIRs in blocks that equate to 1/256th of the entire IPv4 address space (each block is referred to as a “/8” or “slash-8” and includes just over 16 million IP addresses). The most recent assignment means that there are now only 12 of these blocks available, which is less than five percent of the entire IPv4 address pool.

The final five blocks of IPv4 addresses will be distributed simultaneously to the five RIRs, leaving only seven blocks to be handed out under the normal distribution method.

According to current depletion rates, the last five IPv4 address blocks will be allocated to the RIRs in early 2011. The pressure to adopt IPv6 is mounting. Many worry that without adequate preparation and action, there will be a chaotic scramble for IPv6, which could increase Internet costs and threaten the stability and security of the global network.