Selection mechanism for the remaining IPv4 address space

9 September 2009

On 30 July 2009, ICANN staff divided the remaining unallocated IPv4 /8s into two groups. The first group contains the /8s in which Duane Wessels' 2008 research showed significant unofficial use. The second group contains the /8s which showed less unofficial use.

The five /8s which had previously been selected for the implementation of the Global Policy for the Allocation of the Remaining IPv4 Address Space were removed from this second pool of more desirable /8s. Four more /8s were then removed from this pool: two for each of the newest RIRs. Those RIRs have the fewest IPv4 /8s and service the regions with the most developing economies. It is ICANN staff’s judgment that those RIRs should have blocks from the most desirable /8s reserved for their future use. In the event that the other /8s are exhausted before these reserved /8s are allocated, they will become available to all RIRs.

When the two newest RIRs qualify for additional IPv4 address space, they will be allocated the /8s reserved for them. When the other three RIRs qualify for additional IPv4 address space they will be allocated one /8 from each of the two pools. The /8 selected from each pool will be decided by a verifiable random selection mechanism based on the method described in RFC 2777.

The sources of randomness used are the prices of the Hang Seng Index, the FTSE 100, and the Dow Jones Industrial Average from midday at the exchange site the business day after the request is received, as published on the Yahoo! Finance web site.

After reserving the five /8s for final distribution and the four /8s for the newest RIRs, the pool of less desirable IPv4 /8s is the larger of the two. Consequently, when the smaller pool is gone, all the /8s allocated to APNIC, ARIN and the RIPE NCC will be from this pool. In the event that IPv4 /8s are still reserved for AfriNIC and LACNIC when the other two pools have been fully allocated, those /8s will become available to all RIRs.