IPv4 Address Space: October 2003
There have been press articles posted over the past year that make statements about the remaining pool of IPv4 address space. A recent article states there is a shortage and that Internet Protocol Numbers will run out some time in the year 2005.
The Regional Internet Registries (RIRs) do not themselves make predictions about when the remaining IPv4 address space will be depleted. They do, however, report on the rates of RIR allocation of IPv4 address space and on the state of the remaining pool of IPv4 address space.
The information provided in these RIR reports makes it apparent that many of the recent claims regarding IPv4 address space shortage are speculative and are not based on authoritative, publicly available statistics.
IPv4 Address Space: Current Statistics
The global pool of IPv4 addresses is administered by the Internet Assigned Numbers Authority (IANA), which allocates address blocks to Regional Internet Registries (RIRs) as they are required. The IPv4 allocation unit in this case is the "/8 block", equivalent to approximately 16 million addresses. It should be noted that as of 30 June 2003 the global pool of IPv4 address space contained 91 of these blocks for this purpose.
The RIRs report on statistics regarding IPv4 allocation on their respective web sites and present a "Joint Statistics" report at each of the RIR meetings and at other Internet industry meetings several times yearly. This information is publicly available and provides the most up-to-date statistics on rates of IPv4 allocation.
This report states that the RIRs have collectively allocated 19.59 /8 equivalents in the four and a half years between January 1999 and June 2003. It also identifies that there are 91 /8 equivalents held by the IANA in reserve for future allocation by the RIRs.
Based on today’s total global allocation rate of approximately 4.25 blocks per year in 2002, or 5.5 blocks in 2001, and the remaining pool of 91 blocks held by IANA, it is unrealistic to assume that there is an imminent shortage in the IPv4 address space. Even allowing for a dramatic increase in address consumption rates, it is highly probable that IPv4 address space will last well beyond the two years predicted by some.
IPv4 Address Space: Allocated Globally According to Regional Needs
The RIRs are not-for-profit membership organisations dedicated to providing neutral and fair Internet resource distribution to their members, while ensuring the conservation and aggregation of IPv4 address space. The IANA policies for allocation of IPv4 address blocks to the RIRs are applied fairly and are based purely on the documented need for address space.
When IPv4 address space finally "runs out" this will occur at the global level, leaving each region with a relatively small pool of addresses remaining to be allocated.
It has been suggested that Asia will experience an IPv4 address shortage before other regions. This is simply not true. This is because addresses are distributed in a co-ordinated fashion from a single global pool, and there is no system whereby that pool is exclusively divided among, or pre-allocated to, different countries or regions. Through the current system of address administration, IP addresses are allocated according to immediate need wherever that need is demonstrated and it is simply not possible for isolated "shortages" to exist.
As has been done in the past, the RIRs will continue to report regularly on the registration and allocation rates of Internet Protocol Numbers, and will work closely with the IANA to ensure the efficient management of the remaining IPv4 address space.