IPv4 address exhaustion just got more real! In an announcement on Tuesday, the Internet Corporation for Assigned Names and Numbers (ICANN) indicated that they are starting the process of allocating the final available blocks of IPv4 addresses out to the Regional Internet Registries (RIRs) from the IANA recovered address pool. (ICANN is the operator of IANA.) As the announcement states:

ICANN announced today that it has begun the process of allocating the remaining blocks of Internet Protocol version 4 (IPv4) addresses to the five Regional Internet Registries (RIR). The activation of this procedure was triggered when Latin America and Caribbean Network Information Centre’s (LACNIC) supply of addresses dropped to below 8 million. This move signals that the global supply of IPv4 addresses is reaching a critical level. As more and more devices come online, the demand for IP addresses rises, and IPv4 is incapable of supplying enough addresses to facilitate this expansion. ICANN encourages network operators around the globe to adopt IPv6, which allows for the rapid growth of the Internet.

This is it, folks.

We’ve been talking for many years about IPv4 addresses running out. Now it’s happening.

[NOTE: Back in February 2011, IANA allocated their final IPv4 address blocks from the “free pool” of IPv4 addresses. IANA then worked with the five RIRs to recover unused IPv4 address blocks and establish the “recovered address pool”. The agreement was that allocations would start from this pool when the first RIR hit its last /9 block of IPv4 addresses, which LACNIC recently did. After this recovered pool has been allocated to RIRs, there simply aren’t any more IPv4 addresses for IANA to give out.]

Yes, there are enough IPv4 addresses in the overall system right now that we’re not running out of addresses TODAY … but we are basically OUT at the top-level. The final allocations will occur over the next few months as part of the Global Policy for Post Exhaustion IPv4 Allocation Mechanisms by the IANA.

It will be increasingly hard for network operators to get more IPv4 addresses for new customers and new networks.

If you are not yet planning for a transition to IPv6, you really need to get going now! If you want to grow your network, the simplest and easiest path will be to make the move to IPv6. Check out our “Start Here” pages to learn how you can get going!

DO YOU HAVE A GREAT EXAMPLE OF MOVING A NETWORK OR APPLICATION TO IPv6? We are seeking IPv6 case studies for our upcoming celebration of the 2nd anniversary of World IPv6 Launch. If you have a great IPv6 story, we’d love to help share that story for others to learn from it. Please let us know.

UPDATE #1 – If you are interested in learning more about how IPv6 adoption is going, check out our list of IPv6 statistics sites. In particular, look at the World IPv6 Launch measurements, where this month Verizon Wireless crossed over 50% IPv6 for the first time!

UPDATE #2 – There is an excellent discussion thread currently underway on Hacker News about this article.

UPDATE #3 – The Number Resource Organization (NRO) has a statement up on their website.