Internet Protocol Version 6 (IPv6) is here for real. The U.S. Office of Management and Budget has set a deadline of Sept. 30 for government agencies to give employees the capability to access the Internet via IPv6. In fact, now is the time for all of us to start thinking about when we should stop using IPv4. Here are the reasons why:
First, we are running out of available IPv4 addresses. According to the American Registry for Internet Numbers (ARIN), there was only one last /8 (Class A) IPv4 address block available as of April 25, of which only one /9 IPv4 address block can be possibly allocated to new requests for IPv4 addresses. One estimate suggests that IPv4 addresses in North America will be fully depleted sometime in late 2014 or early 2015. The IPv4 addresses for Asia-Pacific and Europe have already been depleted, in 2011 and 2012, respectively.
Second, not only has the U.S. government mandated that all federal agencies start the transition to IPv6, but all vendors wishing to do business with the federal government are required by the Federal Acquisition Regulation to be in full compliance with IPv6 for all IT-related products and services.