The international bodies in charge of distributing Internet Protocol addresses announced Thursday, Feb. 3, that the last available IPv4 addresses have been distributed.

The milestone will prompt the move to the next-generation IPv6 (Internet Protocol version 6).

“This is truly a major turning point in the ongoing development of the Internet,” said Rod Beckstrom, president and CEO of the Internet Corp. for Assigned Names and Numbers (ICANN), one of the nonprofits that coordinates IP distribution.

IP addresses are the numeric identifiers that are assigned to every device connected to the Internet.

IPv4 uses four 8-bit-number (32-bit total) addresses, which limits the address space to nearly 4.3 billion unique addresses, according to CNET. IPv6, by contrast, “will open up a pool of Internet addresses that is a billion-trillion times larger than the total pool of IPv4 addresses,” according to ICANN, “which means the number of IPv6 addresses is virtually inexhaustible for the foreseeable future.” IPv6 uses four 32-bit numbers, or 128 bits total.

It’s up to Internet service providers to make the switch, but government also has a role to change. In September 2010 U.S. CIO Vivek Kundra announced a two-year plan to upgrade all federal government websites to support IPv6.

Content providers, including those who manage public-facing websites, must support IPv6 or else someday risk that those who connect through IPv6 won’t be able to access the website.

“Nobody was caught off guard by this,” Beckstrom said. “The Internet technical community has been planning for IPv4 depletion for quite some time. But it means the adoption of IPv6 is now of paramount importance, since it will allow the Internet to continue its amazing growth and foster the global innovation we’ve all come to expect.”

Source: Number Resource Organization