Marking an important milestone in the evolution of the Internet, the American Registry for Internet Numbers (ARIN), the nonprofit association that manages the distribution of Internet number resources for its region, announced today that it has issued the final IPv4 addresses in its free pool. The attention now shifts to IPv4’s successor, IPv6.

“While ARIN will continue to process IPv4 requests through its wait list and the existing transfer market, organizations should be prepared to help usher in the next phase of the Internet by deploying IPv6 as soon as possible,” said John Curran, ARIN’s President and CEO.

While ARIN will continue to process and approve requests for IPv4 address blocks through its recently announced Waiting List for Unmet IPv4 Requests, or through the IPv4 Transfer Market, organizations looking to add or transfer IPv4 space should be aware that the exhaustion of the ARIN free pool does trigger important changes in ARIN’s Specified Transfer Policy and Inter-RIR Transfer Policy. This change specifically impacts those organizations that have been the source entity in a specific IP address space transfer within the last twelve months. Effective today, because exhaustion of the ARIN IPv4 free pool has occurred for the first time, there is no longer a restriction on how often organizations may request transfers to specified recipients.

In the future, any IPv4 address space that ARIN receives from IANA, or recovers from revocations or returns from organizations may be used to satisfy approved requests on the Waiting List for Unmet Requests. If ARIN is able to fully satisfy all of the requests on the waiting list, any remaining IPv4 addresses would be placed into the ARIN free pool of IPv4 addresses to satisfy future requests.

ARIN is hosting a recurring blog series on IPv4 depletion status on the Team ARIN website to keep the community informed about the status of the ARIN IPv4 free pool and is educating organizations who want to reach the whole Internet, not the old Internet with a campaign to promote IPv6, called Get6. Organizations must prepare for IPv6 now to ensure their future success in a changing web environment.