Internet Protocol (IP) addresses allow computers or other digital devices to communicate with each other via the internet. Simply put, if a computer wants to send another computer an electronic file, it needs to know the IP address of the remote device. This also means each device must have a unique IP address.

Ensuring that each device has a distinct IP address falls under the auspices of the nonprofit organization Internet Corporation for Assigned Names and Numbers (ICANN). A department of ICAAN, Internet Assigned Numbers Authority (IANA), is directly responsible for coordinating the IP-addressing systems, of which there are two versions: IPv4 and IPv6.

The IPv4 addressing scheme was deployed in 1983 and is still the most commonly used version. It consists of 32-bit numbers that are usually depicted in dotted decimal notation similar to the diagram.

As noted in the diagram, using a 32-bit numbering scheme allows for just over four billion addresses. Even back in 2008, experts were raising the alarm that ICANN would run out of numbers. And even more to the point, if pundits’ estimates are correct, Internet of Things (IoT) devices will number more than the total possible IPv4 addresses by the end of 2015.

Executive summary

  • What it is: IPv6 or Internet Protocol version 6 is an address system not unlike addresses used to identify homes and buildings. IPv4 and IPv6 protocols define how addresses associated with networked (internet or otherwise) digital devices are created.
  • Why it matters: The IPv4 numbering system will soon run out of addresses. Even more important, the internet will run better on IPv6.
  • When this is happening: Now, though the transition is slow going.
  • Who this affects: Everyone — from consumers at home to employees of huge enterprise organizations — as long as internet access is required.
  • What individuals need to do: Visit one of the numerous websites that test whether your network connection is running IPv4, IPv6, or both.
  • Will IPv6 addresses run out like IPv4? There are brave souls who say it is impossible to use all 340 undecillion IPv6 addresses. I remember a similar statement being made back in 1981 when IPv4 was ratified.
  • What happened to IPv5? IPv5 or Internet Streaming Protocol never became ratified. IPv5 defines an experimental real-time streaming protocol that was eventually melded into Asynchronous Transfer Mode protocols. IPv5 was not used to avoid confusion, hence IPv6.

What it is

IPv6 uses a 128-bit numbering scheme and should have enough addresses — 340 undecillion — for the foreseeable future. Besides having sufficient addresses, the IPv6 protocol offers improvements in network management, mobility, and Quality of Service (QoS).

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Why it matters

Tech pundits, including me, have been warning for years that the IPv4 numbering system will run out of addresses. That said, smart engineers always seem to figure out a way around the numeric limitation — Network Address Translation (NAT) for example.

The better answer as to why it matters is that the internet will run better on IPv6. Simply put, afterthought fixes such as NAT break capabilities that equipment manufacturers, especially those building IoT devices, are counting on being available.

For example, current IoT devices supplied with NAT (non-routable across the internet) addresses due to the lack of internet-routable IPv4 IP addresses are able to access the internet just fine. However, these same IoT devices hiding behind a NAT perimeter are invisible to other IoT devices on the internet, which defeats the whole purpose behind the IoT.

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Who this affects

This affects anyone that requires internet access. Other than IT professionals, most people will not know whether they are using an IPv4 or IPv6 address. The switchover has been in progress for so long that most of the issues have been addressed.

There are five Regional Internet Registries (RIR). Each RIR provides services related to the technical coordination and management of address resources in its respective service region. Each RIR has valuable general information about IPv6, plus information specific to the RIR’s area of responsibility.

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When this is happening

Right now, though the transition is slow going. It’s not as if equipment is not ready for IPv6.

The following image from Google displays the number of users who connect to Google using IPv6 for the years 2009 to 2015. Seven percent is not many.

There are several reasons why the transition to IPv6 has been slow. One reason is: Why replace perfectly good equipment just to transition to IPv6? That is a financial outlay most companies are not willing to make until absolutely necessary. Besides concern for the bottom line, company executives are cognizant that customers will not notice any improvement in service. To quote the executives I talked to, “There is no real benefit of being an early adopter.”

The protocol was ratified in 1998, and most if not all network-based equipment is capable of running IPv4, IPv6, or both simultaneously. When it comes right down to it, IPv6 is complicated. One does not just turn off IPv4 and start using IPv6. The good news is that engineers and administrators are working hard to make this as painless as possible.

As to when the transition will begin in earnest, that is anyone’s guess. Networking gurus have stated it will take a significant event, like the bad guys finding a major flaw in IPv4, to hasten the migration to IPv6.

Leslie Daigle, former Chief Internet Technology Officer for the Internet Society, offered another reason why IPv6 does not have a large installed base after so many years: “The lack of real backwards compatibility for IPv4 was the single critical failure.”

Throughout IT’s history, most next-step innovation allowed the previous version to coexist — that’s not the case with IPv4 and IPv6. And as complex as IPv6 is, companies are not going to drop IPv4 and immediately start using IPv6. That became especially apparent when an entire cottage industry blossomed into existence creating tools that allowed IPv4 and IPv6 to exist concurrently on the same network.

What is dual stack, tunneling, and NAT-PT?

Welcome to the transition phase. The Internet Engineering Task Force (IETF) set up the Next Generation Transition (NGTrans) working group to figure out ways to make the IPv4/IPv6 interworking and ultimate transition as smooth as possible. To accomplish that, the NGTrans working group decided on the following interworking/transition technologies: dual stack (RFC2893), tunneling (RFC2893), and NAT-PT (RFC2766).

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What you need to do

One way to keep on top of the situation is to visit one of the numerous websites that test whether your network connection is running IPv4, IPv6, or both. Test is one such website. The following screen shot indicates the computer has either IPv6 turned off or the network is not running the protocol.

To determine whether IPv6 is enabled on the networked device requires checking the network adapter’s properties. As shown below, the computer tested at Test IPv6 has IPv6 enabled. As noted in the comment section of the Test screen shot, the decision to run only IPv4 was made upstream of the networked device. CenturyLink’s DNS server either cannot access the IPv6 internet or is not configured to use IPv6.

Closing thoughts

More or less, this is where we are today. I have been told it will take a major event to build enough momentum for businesses to switch over to IPv6. Time will tell.

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