Press Release

Press Release

23 April 2014

Lori Russo

Depletion of IPv4 Address Space Triggers Final Phase of ARIN Countdown Plan

- Dwindling IP Address Inventory Underscores Need for IPv6 Adoption -

Chantilly, VA - 23 April 2014 -The American Registry for Internet Numbers (ARIN), a nonprofit association that manages the distribution of Internet number resources within its region, announced today that it has reached its final /8 equivalent block of IPv4 address space in its available inventory. As a result, ARIN has entered the fourth and final phase of its IPv4 Countdown Plan

This stage of ARIN's Countdown Plan dictates that all requests for IPv4 addresses are processed on a strict "First in, First out" basis. All requests for IPv4 resources of any size will be subject to team review by ARIN's Resource Analysts, with the larger requests requiring approval by the Department Director. This chronological queuing procedure will apply to initial requests and all related response cycles.

"As we reach this final stage of our Countdown Plan, we want to remind businesses that they should make IPv6 adoption a priority in order to support continued Internet growth and innovation," said John Curran, president and CEO of ARIN.

ARIN may experience situations where it can no longer fulfill qualifying IPv4 requests due to a lack of inventory of the desired block size.  At that time, the requestor may opt to accept the largest available block size they can justify under policy or they may ask to be placed on the Waiting List for Unmet Requests.  Full details about this process are available at: 

You can learn more about the IPv4 Countdown Phase Four plan at:

Questions about procedural changes should be directed to the Help Desk at or +1.703.227.0660.


About the American Registry for Internet Numbers (ARIN)

ARIN is the nonprofit corporation that manages the distribution of Internet number resources – IPv4, IPv6, and Autonomous System numbers – in its service region, which includes Canada, many Caribbean and North Atlantic islands, and the United States. More information on IPv6 adoption is available at and