Under the policy for this stage, known as Stage 3, these addresses will be parcelled out to organisations according to strict conditions. Any one organisation will only be entitled to a maximum of 1024 individual addresses -- a /22 block.
Dean Pemberton, technical specialist with New Zealand's IPv6 Task Force, says under these restrictions the final block of addresses could last for up to four years. But the snag, according to Pemberton, is that large ISPs such as Telecom and TelstraClear will qualify on the same basis as any other organisation; they get only 1024 addresses from the pool, so they could be constrained in providing addresses to their downstream users.
APNIC's objective during Stage 3 is to provide IPv4 address space for new entrants to the market and for those already deploying IPv6 and in need of IPv4 addresses to assist the transition process, says a statement from the organisation.
"The strict intention is that what members do with their one last chunk of space from APNIC is up to them, Pemberton says. "It's highly recommended that it is treated as 'special' IPv4 space to aid in the transition to IPv6, but it is not mandated."
The /8 block now being allocated is one of the last five available, which were parcelled out to APNIC and the other four Regional Internet Registries at the end of January. Shortly before that, two /8 blocks were allocated to APNIC, so these have been exhausted in two-and-a-half months.
However, Pemberton says that should not be taken as an indication of the likely speed of exhaustion of the last block, since the previous two were not subject to the same restrictions "and I know some quite large blocks were taken up".
Currently the APNIC website refers to the maximum allocation under Stage 3 as a /22, but Pemberton says there is a possibility this may be further reduced as blocks run out.
Smaller blocks than /22 are seen as problematic for routing, he says and organisations, particularly ISPs, don't like to take them.
The implication of reaching Stage 3 is clear -- organisations that have not begun work on adopting the expanded IPv6 addressing scheme should do so now.
"We encourage Asia-Pacific Internet community members to deploy IPv6 within their organisations," says APNIC's Stage 3 press release.