Although it is a well-known fact that IPv4 address space is nearing exhaustion, this document reviews the current global and regional status of IPv4 address availability at the end of 2012. The information contained in this report can be found on the various websites cited throughout this document; however, this information has not been compiled in any single location or translated into the languages spoken in our region.
We assume that the reader is familiar with the current Internet address distribution and allocation system, as well as with the relationship between the IANA, regional registries, and ISPs/end users. For more information, please visit IANA’s website at: http://www.iana.org/numbers
Addresses Available in the IANA Pool
In February 2011, the central stock of IPv4 addresses administered by the Internet Assigned Numbers Authority (IANA) was finally exhausted. At that time, each RIR was assigned one of the five remaining blocks according to the global policy in force. More information on this milestone ceremony can be found at: http://lacnic.net/sp/anuncios/2011-agotamiento-ipv4.html
A complete distribution map of the original 256 /8 blocks can be found on IANA’s website at the following URL:http://www.iana.org/assignments/ipv4-address-space/ipv4-address-space.xml
Since then, each RIR has only had access to its own IPv4 stock and, consequently, each RIR has had different projected IPv4 exhaustion dates for their region. The current situation for the five RIR service regions is analyzed below.
Addresses Available in RIR Pools
Each regional registry has a policy that is triggered when IPv4 resources reach a “practical” exhaustion limit. This limit is typically reached when a single /8 block remains, although LACNIC reserves two /12 blocks. After this “virtual exhaustion,” regional registries will no longer assign IPv4 addresses based on demonstrated need but will rather set a maximum block size to be assigned per organization – typically a /22. Once this stage is reached, even though the RIR still has some addresses, the RIR stock is considered to be exhausted as it can no longer satisfy the actual needs of ISPs and other organizations.
APNIC was the first regional registry to run out of IPv4 addresses. On 15 April, 2011, APNIC started to use its last remaining /8. This event triggered a policy that restricts assignments to a single /22 per organization, either new or pre-existing. More information on APNIC’s website: http://www.apnic.net/publications/news/2011/final-8
It is interesting to analyze the following graph by Geoff Huston which clearly shows how scarcity began in April 2011. While in 2010 the average demand and number of assignments were in the order of 2 million addresses per week, the graph shows that the number of address assignments has been negligible after the “last /8” policy was triggered. It also clearly shows increased demand during the first weeks of 2011 in anticipation of the moment when that policy would be triggered.
On 14 September, 2012, Europe’s regional registry also started to use its last remaining /8. The policy in force states that, from that moment on, the maximum assignment size is a /22. The original announcements from RIPE can be found at the following links:
ARIN, LACNIC and AfriNIC
These three registries have not yet reached their last /8 block and there are different estimates as to when each RIR will begin to use their reserve block. One of the better known projected RIR address pool exhaustion date estimates is the one prepared by Geoff Huston and available at the following link: IPv4 Address Report: http://www.potaroo.net/tools/ipv4/index.html
RIR Address Pool Exhaustion Dates:
Addresses in RIR Pool (/8s)
This information can be seen in graphic form at the following link: http://www.potaroo.net/tools/ipv4/plotend.png
In turn, LACNIC has its own IPv4 exhaustion date projections: http://www.lacnic.net/web/lacnic/reporte-direcciones-ipv4
As we can see, an important part of the global Internet is based in regions where the regional registries have already exhausted their IPv4 resources and where new IPv4 requests now face strict restrictions. Moreover, based on the projections cited above, we can safely assume that during the second half of the upcoming year most of the Internet will have insufficient IPv4 resources. For all of the above, we should begin thinking that the IPv4 protocol is exhausted and start thinking of an IPv6-based Internet. In our region, particularly, we should consider that we only have a year and a half to adopt the new version of the IP protocol and thus avoid the problems associated with IPv4 exhaustion.