专家警告IPv4地址即将用完

BOC

按照目前的分配速度，现有的地址将在340天内用光。

尽管IPv6已经提出了很多年，许多互联网业界--包括ISP和网站---都不情愿投资去推动IPv6

In less than a year, the world will run out of internet addresses and inaction by internet providers could lead to broken applications and more expensive net connections, experts warn.

The protocol underpinning the net, known as IPv4, provides only about 4 billion IP addresses - not website domain names, but the unique sequence of numbers assigned to each computer, website or other internet-connected device.

The explosion in the number of people, devices and web services on the internet means there are only about 232 million left. This allocation is set to be exhausted in about 340 days.

"When the IPv4 protocol was developed 30 years ago, it seemed to be a reasonable attempt at providing enough addresses, bearing in mind that at that point personal computers didn't really exist. The idea that mobile phones might want an IP address hadn't occurred to anybody because mobile phones hadn't been invented [and] the idea that airconditioners and refrigerators might want them was utterly ludicrous," said John Lindsay, carrier relations manager at internet service provider (ISP) Internode.

Internet experts derived a solution to the problem several years ago, which involves moving to a new protocol, IPv6, that provides trillions of addresses for every person on the planet. But most of the internet industry - including ISPs and websites - have been reluctant to make the necessary investments to move to IPv6.

The issue has been compared to Sydney running out of phone numbers when using a seven-digit system, which was solved by adding a 9 to the front of all numbers. But with the internet the solution is much more complex than that, as all devices that connect to the net will need to be reconfigured or upgraded.

Geoff Huston, chief scientist at APNIC, which allocates IP addresses for the Asia-Pacific region, has been trying to raise awareness of the problem for 10 years.

He says the rise of smartphones, PCs and internet-connected appliances means the address pool will run dry within a year, decades quicker than even he predicted.

Huston said one of the biggest impediments to solving the problem was the sheer scale - all devices on IPv4 will need to be upgraded to support IPv6, as the two versions aren't backwards compatible. Consumers will need to upgrade the software on their computers and networking equipment and, in some cases, buy completely new hardware.

"This is almost like a lot of the other challenges we face in society like climate change ... if everyone does something, the right thing will happen, but if one individual does the right thing, it doesn't make a difference," said Huston.

"Your ISP needs to do a lot of work, and if you're not willing to pay more money to your ISP, your poor old ISP has got to spend [extra] money without [extra] income."

Huston said that, once the available internet addresses ran out, a kind of black market for IP addresses would be created where "those services that have the highest capacity to pay will still be able to get more addresses, but those who can't get denied".

Upfront costs of moving to the new protocol will be high but Huston said delays would push costs even higher.

As a stop-gap measure, Huston said ISPs would begin forcing multiple customers and devices to share single internet addresses, which would lead to common web applications ceasing to work. Huston pointed to web applications such as Gmail, Google Maps and iTunes as examples of those that would break.

"Over the years unless we embark on IPv6 then the internet will get slowly more and more strangled and applications will work in stranger ways," Huston said.

James Spenceley, chief executive at wholesale ISP Vocus, gave another example of an application that might cease to work under a shared IP address system: internet telephony.

"A VoIP phone needs to have a certain port number, so across 20 customers only one of them will work," he said.

"An internet service that resembles the service today might become a premium service, where you do have a unique IP address, [but] you might pay more."

Fortunately, some vendors have taken steps to support the move to IPv6. The Windows and Mac operating systems both support the new protocol, as do some smartphones such as the iPhone. Australian ISP Internode is the first to offer IPv6 as a commercial service.

Providers of popular web services such as Google and Facebook are also making good progress in adopting IPv6.

Google's chief internet evangelist and one of the founding fathers of the internet, Vint Cerf, appeared in an online video in June urging ISPs to do more to transition to IPv6.

"Moving from IPv4 to IPv6 is a little like changing the roads and tyres while continuing to drive along in your car," said Lindsay from Internode.

"It's been expensive, it's been time-consuming and it doesn't produce an immediate return on investment so it's the kind of thing that isn't popular with CFOs. However, it's laying an important foundation for what happens over the next few years as it becomes increasingly difficult to obtain IPv4 addresses."