Remaining IPv4 Address Space Drops Below 5%

Posted: Monday, 18 October 2010

The Number Resource Organization (NRO) announced today that less than five percent of the world's IPv4 addresses remain unallocated following IANA's distribution of two IPv4 /8s to APNIC. The IANA IPv4 free pool has now dropped to 12 /8s, or 4.69%. 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 five Regional Internet Registries (RIRs).

The number of IPv4 allocations is expected to grow by only 8% this year. In contrast, 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. These statistics indicate an absence of any last minute "rush" on IPv4 addresses and a strong momentum behind the adoption of IPv6.

When the IANA IPv4 free pool has only five /8 blocks remaining, they will be simultaneously distributed to the five RIRs in accordance with global Internet number resource distribution policy. This means that only seven blocks remain to be handed out under the normal distribution method. At 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. ARIN encourages you to deploy IPv6 now. Visit for more information on IPv6 adoption, or contact us at with any questions.


Communications and Member Services
American Registry for Internet Numbers (ARIN)