North America has officially run dry of new IPv4 addresses, the numbers that computers use to find each other on the internet.
This means the region can allocate no more of the 32-bit network addresses to web hosting companies, cloud providers, organizations and individuals: they're all taken. The space is full, and it's being heralded as a key milestone in the internet's growth.
In the past few minutes, ARIN – the non-profit that oversees the allocation of IP addresses in North America – confirmed the available pool of the 32-bit network addresses is totally depleted. Last night, the team estimated there were just 1,024 IPv4 addresses left in its pool – dregs, in other words. Now that's all gone.
"The exhaustion of the free IPv4 pool was inevitable given the internet’s exponential growth,” ARIN boss John Curran said today.
The IPv4 space globally offers 4,294,967,296 network addresses – which seemed like an awful lot back in the 1970s when the internet was coming together. (Not all of those are usable on the public internet as some chunks are reserved. For example, the familiar 10.x.x.x and 192.168.x.x blocks are used for internal networks.)
Since then, the, er, information superhighway, cyber-space, or whatever you want to call it, has exploded, and the seemingly endless supply of IPv4 addresses is running out.
APNIC, which allocates addresses in Asia-Pacific, more or less ran out of available IPv4 addresses in 2011; RIPE, which oversees Europe, the Middle East and parts of Central Asia, was running on fumes by 2012; and LACNIC, which manages Latin America and the Caribbean, hit rock bottom in 2014. All that's left is AFRINIC, which oversees Africa, and is expected to run out of IPv4 addresses in 2019.
IPv6 uses 128-bit addresses, and there are 3.4 × 1038 available – that's 340 undecillion, although, practically speaking, 42 undecillion are usable. Plenty to go around now that IPv4 is scarce, in other words.
Forget IPv4 – get on with IPv6
Curran told The Register now is the time to move your website or organization over to IPv6, a space that "contains enough address space to sustain the internet for generations."
"Organizations should be prepared to help usher in the next phase of the internet by deploying IPv6 as soon as possible,” he said today.
In an interview, the ARIN CEO told us normal netizens don't need to worry as their ISPs will gradually – if not already – provide them with IPv6 connectivity so they can access websites and other stuff on the internet using that huge space. This should happen without broadband subscribers having to change a thing. Comcast, for one, has detailed its IPv4-IPv6 transition plans here.
Adding an IPv6 address and connectivity to your own website will bring benefits, he told us, because those networks tend to be less congested and more direct – meaning people at home using IPv6 will reach your IPv6 site faster, typically.
"People at home on broadband don't need to do anything, and there's a benefit to using IPv6: it's less congested and more direct," he said.
"If you have a website on the internet, you'll want to talk to your hosting provider, and get your servers reachable by IPv6. If you have content on the internet, you should be thinking about IPv6. This applies to a huge number of organizations of the world.
"If you happen to be an ISP, you're paying attention to this already. IPv6 networking is growing fast, and mobile operators in particular are picking up IPv6 and using it in some cases for years."
Reactions and what happens next
“When we designed the Internet 40 years ago, we did some calculations and estimated that 4.3 billion terminations ought to be enough for an experiment. Well, the experiment escaped the lab,” said Vint Cerf, the ARIN chairman who is often dubbed the father of the internet.
“The internet is no longer an experiment; it is the lifeblood of commerce, communication and innovation. It needs room to grow and that can only be achieved through the deployment of IPv6 address space.”
Tom Coffeen, chief IPv6 cheerleader at Santa Clara-based server biz Infoblox, told us not to panic: "Though the IPv4 well has run dry and threatens service providers, the sky hasn’t yet landed on enterprise networks. Most enterprises still rely on private IPv4 for their internal networks.
"The small number of public, routable IPv4 addresses required to connect enterprise networks to the Internet is typically provided by the ISP, making IPv4 much more critical for Internet services providers. ISPs generally need routable addresses to connect mobile and broadband subscribers."
In July, ARIN was down to its last 130,000 or so IPv4 addresses. If any IPv4 addresses are returned to ARIN, or more are allocated to the team by internet overseers IANA, they will be given to people on a waiting list of unmet allocations. Organizations and individuals can transfer their IPv4 addresses to others – indeed, address brokers such as the IPv4 Market Group are going to have a field day.
"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," the team told us. More details can be found here, by Team ARIN.
Cloud providers, web hosting companies, and other organizations that dish out public IPv4 addresses to customers aren't completely stuffed by today's news: they are usually allocated the addresses in blocks of 256, 512 or more, and will have stockpiled modest reserves. When those supplies run out, IPv6 take-up really will explode. ®