Since IANA ran out of IPv4 addresses, people are increasingly aware of how short the remaining lifetime of IPv4 is. With World IPv6 Day taking place this week, the issue has come into even sharper focus.

Since March 2011, the RIPE NCC has been publishing the size of its pool of available IPv4 addresses. All five Regional Internet Registries (RIRs) regularly publish the status of their IPv4 address pools. In the image below, you can see how the number of IPv4 addresses in the RIPE NCC pool changes over time.

The graph is updated weekly and is adjusted up or down as IPv4 addresses are distributed and returned. Currently, around 4.5 /8s (76 million IPv4 addresses) are still available, with a stable decrease of less than 1 million addresses on average per week over the last three months. A run-out-fairly policy was implemented to ensure a gradual reduction of the allocation and assignment periods. This ensures a fair distribution of the remaining address space.

The graph also includes the 12.58 million IPv4 addresses temporarily set aside for the De-Bogonising New Address Blocks project. Under this project, pilot prefixes are announced to improve the routability of new address blocks. This is done only before real production prefixes are announced from the new block.

The last /8 that the RIPE NCC received from the IANA on 3 February 2011 is included in this graph and is shown by the yellow horizontal line. This last /8 will be allocated according to section 5.6 of the IPv4 Address Allocation and Assignment Policies for the RIPE NCC Service Region. Each Local Internet Registry (LIR) can receive one /22 allocation from the last /8 to ensure that new LIRs can still get IPv4 address space in the future. To receive this allocation, the LIR must have an IPv6 allocation to prepare for the coming transition to IPv6.

The RIPE NCC available pool graph can also be found on the RIPE NCC website.