As the free pool of IPv4 addresses reaches its end, we looked at
the evolution of the amount of unassigned IPv4 address space
over time. By 'unassigned', we mean address space not yet
allocated to a Local Internet Registry (LIR) or assigned to an
end user. LIRs are typically Internet Service Providers or
enterprises operating an IP network. See our findings in the
graph below. The graph shows that the decline of IPv4 has been
mostly linear. This means that the Regional Internet Registries
(RIRs) have been allocating roughly ten /8s1 each year since
2004. There was a small decrease in allocations in 2008 — due
undoubtedly to the economic crisis — before accelerating again
in mid-2009. Thirty-three unassigned /8's of IPv4 addresses
remain as of 1 October 2010. An overly simplistic extrapolation
would mean that the RIRs still have three years left to hand out
IPv4 address space. This is no reason to relax. We have clearly
entered the last phase of available IPv4 address space. In 2010
the need for IPv4 addresses