IP or 'Internet Protocol' addresses are assigned to each device that connects to the internet and is used to ensure web traffic reaches the device of the user that requests the content.
There are different versions of IP addresses conforming to different technical specifications. The IPv4 system of addresses is the one most commonly used, although an IPv6 system has also been developed. IPv6 has been slowly developed since 1995 and comprises 340,282,366,920,938,463,463,374,607,431,768,211,456 addresses. When IPv4 was conceived in the 1970s, it provided 3.7 billion addresses.
However, only a finite number of IPv4 addresses are left unallocated and there have been fears that they will run out as the number of connected devices around the world continues to grow. Despite that, rollout of IPv6 addresses in many areas of the world has been slow. A study in the UK published last year warned that the deployment of the IPv6 address system could bring with it connectivity problems and network security issues and also raise privacy concerns.
In a new statement, the body that oversees the identification of websites, ICANN (Internet Corporation for Assigned Names and Numbers), said that the last unused IPv4 addresses have now been handed over to regional registries to be allocated. It said that the 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 said. "ICANN encourages network operators around the globe to adopt IPv6, which allows for the rapid growth of the internet."
"This redistribution of the small pool of IPv4 addresses held by us ensures that every region receives an equal number of addresses while we continue to work with the community to raise support for IPv6," Elise Gerich, vice president of the Internet Assigned Numbers Authority (IANA) and technical operations at ICANN, said. "To continue to fuel the economic growth and opportunity that is brought by the Internet, we are at the point where rapid adoption of IPv6 is a necessity to maintain that growth."
"Redistributing increasingly small blocks of IPv4 address space is not a sustainable way to grow the Internet. IPv6 deployment is a requirement for any network that needs to survive," Leo Vegoda, operational excellence manager at ICANN, said.