Stock Of Free IPv4 Addresses Dwindles Further

The stock of unallocated IPv4 addresses dropped below 5 percent in October, and now there are just two free blocks of addresses remaining

The Internet Assigned Numbers Authority (IANA) has allocated four more blocks of IPv4 addresses to regional Internet registries (RIRs), reducing the pool of free blocks to seven, according to RIPE NCC, the RIR that handles Internet number distribution for Europe, the Middle East and parts of Central Asia.

Five of those seven free blocks are already reserved for the final stage of IPv4 deployment, leaving two blocks unaccounted for, RIPE NCC noted.

Depletion

The blocks were assigned on Tuesday night, with two going to the RIPE NCC and two going to the American Registry for Internet Numbers, RIPE NCC said.

The move comes just over a month after IANA assigned two blocks of IPv4 addresses to APNIC, the Regional Internet Registry for the Asia Pacific region, after which less than five percent of the world’s IPv4 addresses remained unallocated.

The free IPv4 pool dipped below 10 percent in January, and 19 blocks of addresses have been allocated this year, according to RIPE NCC.

The pool of free IPv4 addresses is due to run out in early 2011, according to the Number Resource Organisation (NRO), the coordinating mechanism for the five RIRs – AfriNIC, APNIC, ARIN, LACNIC, and RIPE NCC.

“According to current depletion rates, the last five IPv4 address blocks will be allocated to the RIRs in early 2011,” the NRO said in a statement in October. “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.”

The last five IPv4 blocks are to be distributed equally between the five RIRs, leaving two free IPv4 blocks, according to RIPE NCC. Those are likely to go to APNIC, which handles the Asia Pacific region, according to Axel Pawlik, RIPE NCC’s managing director.

That region is growing quickly, and so the remaining two IPv4 blocks may be allocated by the end of the year, Pawlik said. He has predicted that all those addresses will be used up by January of 2012.

IANA assigns IPv4 addresses to the RIRs in blocks that equate to 1/256th of the entire IPv4 address space, with each block referred to as a “/8” or “slash-8”.

Time for IPv6?

The NRO said it is seeing strong adoption of IPv6.

It expects the five RIRs to allocate more than 2,000 IPv6 address blocks during the course of 2010, an increase of more than 70 percent over 2009’s figures. By contrast, the number of IPv4 allocations is expected to grow by 8 percent 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 NRO said in October.

Nevertheless, Vint Cerf, one of the ‘founding fathers’ of the World Wide Web and Internet evangelist for Google, last month highlighted the need for cash incentives to encourage ISPs and businesses in the UK to move to IPv6.

IPv6 uses 128 bits of address data, giving it much greater capacity to accommodate the growth of the Internet than IPv4 addresses, which contain only 32 bits. It has been calculated that there is capacity for 340 trillion trillion trillion IPv6 addresses worldwide.