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Six things small networks need to know about IPv6

The four horsemen of the Apocalypse.

Above: The four horsemen of the Apocalypse.

Chris Phillips is a network engineering consultant.

In the first week of August, American Registry for Internet Numbers’ remaining IPv4 pool dropped below a critical mark: two /8s, or about 33.5 million IP addresses. A week later, it fell again to 1.88 /8s, meaning another 2 million IP addresses were gone.

If IPv4 were the only protocol out there, the four horsemen would be saddling up right about now.

Of course, it’s not. There’s also IPv6, which has enough addresses to ensure exhaustion won’t be our generation’s problem. But with upgrades come questions.

A /8 is a block of 16,777,216 IP addresses. These blocks can be acquired as a whole — Level(3), for example, owns two /8s — but are most often divided into smaller blocks and allocated to organizations as needed.

As the countdown ticks closer to zero, my consulting clients increasingly ask what this will mean for their networks. Should they worry? Are they too late to be IPv6-ready? The answers vary depending on the networks in question, but the same few queries keep popping up.

Here are some myth-busting pointers about IPv4 and IPv6.

31.5 million isn’t as big as it sounds

31.5 million. That’s all the American Registry for Internet Numbers (ARIN) has left. Sounds like a lot, right? It’s not. This is less than 1 percent of the total approximately 3.75 billion assignable IP addresses that IANA was responsible for assigning to the five regional registries: ARIN (North America); RIPE (Europe); LatNIC (Latin America); APNIC (Asia Pacific); AFRINIC (Africa).

To put that number further into perspective, the remaining pool only has one IP for every 10 Americans. And that’s assuming nobody in Canada or Mexico needs an IP.

With today’s current growth rate of the Internet – not to mention the ever-increasing number of Internet-connected mobile devices – complete IPv4 depletion is imminent. Unless ARIN changes its allocation policies, it’s likely to happen within two years. If last week’s pace continues – 1.5 million addresses gone in a single week – it could be as soon as the coming spring.

IPv6 may be ‘new,’ but it’s older than your intern

It’s true that IPv6 is the newest Internet Protocol (IP) technology, but it isn’t new. In fact, Internet-addressing expansion has been in development for some 20 years. In 1992 the Internet Engineering Task Force (IETF) called for white papers regarding expanding the Internet addressing system.

In 1996, IPv6 support was added to the Linux kernel, and the 6bone IPv6 test and development network was launched. This was all done back in the days of AOL floppies and dial-up modems (but not 56K — that kind of mind-boggling speed wouldn’t be available for another year).

IPv6 was designed to be more reliable, more secure, and easier to deploy. So far, it has been just that.

Some deployment and transition issues are expected in the future, as more networks begin to support IPv6. However, those aren’t IPv6 protocol issues, but rather planning and engineering issues — plus the inevitable human error.

There’s no hurry (but hurry)

At the current rate of allocation, it appears ARIN will be completely depleted of IPv4 addresses sometime in the next 12 to 24 months.

However, there’s no clear answer to the question of exactly when IPv4 addresses will finally be exhausted. Even when ARIN is officially out of IPv4 address space, many smaller service providers and end-user networks will turn to the larger networks such as Verizon, Sprint, AT&T and Level(3), who will surely have some IP space available, at least in the short term.

It will likely be three to four years before we see the first IPv6-only-by-necessity hosts on the Internet.

That said, businesses should start adopting IPv6 as soon as possible. There’s no use in delaying the inevitable.

The Internet at large is not IPv6-compliant

So, is everyone jumping on board and utilizing the protocol upgrade? Sadly, no. As of October 2011, only around 3 percent of domain names and 12 percent of networks had IPv6 support. Those numbers are sure to spike, however, as demand for IPs outstrips IPv4 supply.

Fortunately, thanks to 6to4 proxy gateways, you send your elderly aunt an email across your IPv6 server, and her retirement center (still on IPv4, still running Netscape 2.0 on a 486) will receive the email.

Your PC may not be running on IPv6, but what about your phone?

Many mobile providers have already adopted IPv6, for a variety of reasons. First, and most obviously, demand for mobile devices is exceeding IPv4 availability. Other factors include the increasingly stringent ARIN guidelines for IPv4 allocations and much longer application processing times. Securing 79 decillion (yes, that’s actually a word) IP addresses with very little pushback is a whole lot easier than the painful grind of getting just an additional 1,024 IPv4 addresses from ARIN.

And, yes, while it is true that many cable and DSL have not yet issued IPv6 addresses to end users, it won’t be long before they have no other choice. Most cable and DSL providers have already implemented IPv6 in their core networks and are running what is known as “native dual stack.” This means that a network is IPv4 and IPv6 compatible at the same time.

Making the transition isn’t ridiculously complicated

To most people’s surprise, adding IPv6 to their existing networks is usually not a difficult process. In fact, most routers manufactured within the last five years have IPv6 support already. Those that don’t usually only require a software upgrade to add the functionality.

Once you have confirmed that your router is IPv6-capable, you can request IPv6 address space from your service provider or ARIN. You can use the same autonomous system number on both your IPv4 and IPv6 networks.

The opportunity to position yourself as an early adopter has come and gone, but being IPv6-ready still places you ahead of most networks. It may even create differentiation between you and your competition, giving you a leg up.

Having a network that complies with the latest protocol should be a source of pride, and it’s easier to achieve than you might think.

Chris Phillips is a managing partner with Aptient Consulting Group, a consultancy specializing in network design and implementation. With 17 years in the field, he has guided hundreds of ASN/IP applications. He was also OpenDNS’ sole network engineer when they implemented IPv6 in 2011(OpenDNS was the first IPv6-ready public DNS service in the world).