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The State of IPv6-only

Statistics abound on the deployment of IPv6 and where it might be in a couple years (hint: with a Logistic adoption curve, 50% of the world may be using IPv6 mid-2019).

So that's the first half of the transition: dual stack. How are we doing on actually migrating to IPv6? What is the state of IPv6-only?

It's not as crazy a question as it probably seems to those who haven't started deploying IPv6. In the U.S., according to APNIC, some major networks are already 100% IPv6 enabled (or margin-of-error close).

We see here not just retail tech giants Facebook, Google, Microsoft, and Oracle, but universities like Virginia Tech and Rensselaer, cell giants Verizon, AT&T, and T-Mobile.

Independently, Apple's Tommy Pauly provided this chart at a recent IETF:

Hurricane Electric keeps tabs on many things IPv6, including this table:

IPv4 ASNs5805499.1%
IPv6 ASNs1372223.4%
IPv4-only ASNs4468276.3%
IPv6-only ASNs3500.60%
Dual-stack ASNs5860522.8%

A quick glance at many of those IPv6-only ASNs suggests that they have parallel IPv4-only ASNs. That further suggests that the networks are being built either separately, or modularly: the IPv6 network should not be dependent on the IPv4 network.

This is all consistent with initiatives at Microsoft, Cisco, Deutsche Telekom, T-Mobile, LinkedIn, and Facebook to make at least part of their networks IPv6-only. In most cases, there is translation for IPv4 at the edge, but the network is internally IPv6-only.

To the same end, I've begun working on Retevia, offering IPv4 translation as a service to IPv6 networks.

We no longer need to wonder whether IPv6-only networks will happen someday: they are already happening.

Lee Howard
28 June 2017