Goodbye, IPv4

The last two IPv4 address blocks for the Internet have just been assigned, and now all new Internet addresses now employ IPv6 address spacing. Should companies care?

NetworkWorld reports the last two IPv4 (Internet Protocol version 4) address blocks for the Internet have just been assigned, and, in line with predictions, we've run out of addresses. All new Internet addresses now employ IPv6 address spacing.

As NetworkWorld reports:

"The Internet Assigned Numbers Authority (IANA) assigned two of the remaining blocks of IPv4 addresses - each containing 16.7 million addresses - to the Asia Pacific Network Information Centre (APNIC) on Tuesday, as predicted. This action sparks an immediate distribution of the remaining five blocks of IPv4 address space, with one block going to each of the five Regional Internet Registries (RIR). The American Registry for Internet Numbers (ARIN), which doles out IPv4 addresses to carriers and other network operators in North America, is expected to receive its last allotment of IPv4 addresses today.

Experts say it will take anywhere from three to seven months for the registries to distribute the remaining IPv4 addresses to carriers."

A press conference will be held on Thursday by the IANA to discuss the matter further.

So what?

Companies may feel some issues if they are using networking equipment more than a decade old. Vendors have been preparing for the changeover to IPv6 -- which employs 128-bit address spacing to accommodate an exponentially larger number of Internet addresses -- for several years now. For network operators, there is some work, as they "must either deploy complex, expensive network address translation technologies to share IPv4 addresses among multiple users or adopt IPv6," according to NetworkWorld.

The impending changeover from IP version 4 to IP version 6 won't really be a big deal, and most people won't even notice it as it happens. But the Internet will be running on both protocols for a while, and the head of the American Registry for Internet Numbers (ARIN) cautions that some online applications may run slower as a result.

Still, as John Curran, president and CEO of ARIN, said in a 2009 interview, businesses need to sit up and take notice of the shift from IPv4 to the more expansive IP version 6. The original IPv4 Internet numbering system — which assigns addresses such as —  is a 32-bit system with four billion possible combinations. “That sounds like a lot of numbers, but it really isn’t when you think about the size of the globe and the number of devices being connected these days,” Curran says.  IPv6, with 128-bit addressing space, enables “numbering of all of the molecules in the galaxy,” he says.

All new devices or sites that come along will now use IPv6. Don’t lose too much sleep over your systems, however. Industry planners have been aware of this matter since the 1990s. Most hardware and software has been ready for IPv6 for some time.

Curran advises businesses to check their configurations before the changeover takes place, as glitches may come up. “We can’t actually get an IPv6 host and an IPv4 server to talk to each other, because the IPv4 server only knows 32 bits. It’s much like if your telephone was set up to only ever dial seven digits, and it wouldn’t let you dial 10. Sure you could almost have a conversation, but you couldn’t call most of the world.”

As the changeover occurs, “ISPs are going to have to start using IPv6 to connect customers,” he explains. “Then, they’re going to have to put IPv6 gateways in, boxes that work like network address boxes, to translate IPv6-connected customers to the IPv4 websites on the Internet. That will work, but that’s going to be suboptimal, because those are gateways doing the translation.” This may slow down online applications such as Skype, Voice over IP, real-time video games, which “won’t necessarily run smoothly going through those translators.”

Curran points out that the Internet will be running on two protocols for some time. “If you really want to start a business that’s Internet based, you’re going to want to take your equipment, and make it connected by both IPv4 and IPv6.”

Some businesses have more of a challenge ahead of them than others, Curran says. While the major ISPs have been underway with IPv6, “the content providers are just beginning to work on this,” Curran says. “And that’s going to take a lot of work, and they need to enable a lot of software that we think of as the Web 2.0 software infrastructure. While all the parts may run IPv6, that doesn’t mean your infrastructure is ready.”