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Internet engineers tear into United Nations' plan to move us all to IPv6

Flawed beyond repair, utterly broken, critically endangers the web – and that's the good news

A newly released draft of the United Nations' masterplan to transition the internet to IPv6 has met a furious and despairing response from internet engineers.

"Utterly, utterly, broken. It has no redeeming or worthwhile qualities at all," commented one engineer to an dedicated IPv6 working group at Europe's regional internet registry, RIPE.

Others called the draft "fundamentally flawed," "ill-conceived," "awful," and "pointless to the degree of being self-destructive."

With one day left before RIPE is due to provide formal comments, there is not a single positive sentence, and the general consensus appears to be that the entire document should be binned.

So what is this draft that attracted so much ire from the internet community and why is it so flawed?

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The recommendation [PDF] has been produced by a study group (SG 20) within the UN's International Telecommunications Union (ITU) and was shared for the first time last month with RIPE after the organization specifically requested to see what the group had been working on.

The aim of the recommendation is, in its own words, to "ease the adoption and transition to IPv6 by end-users in developing countries and to reduce the risks of a digital divide in terms of IPv6 adoption."

And to that end, the document paints a picture of advanced Western economies that are slowly moving to 128-bit IPv6 addresses from the traditional and overcrowded 32-bit network address space of IPv4 – while emerging economies remain almost entirely reliant on IPv4 addresses that are in increasingly short supply.

It therefore aims to provide a "reference model" for such countries to help them get to IPv6 faster and more efficiently, with a specific focus on the "internet of things" (IoT) which will require huge numbers of fresh IP addresses to properly function.

So, um, no

The problem that the internet engineers immediately identified, however, is the document's main proposed solution: that IPv4 addresses be mapped to IPv6 addresses, one-to-one.

The document argues: "To enable mapping between and consistency between IPv4 and IPv6 subnet addressing plans, a dual strategy is proposed, with part of the IPv6 subnet addressing plan designed to map corresponding IPv4 addresses, with the possibility to extend the IPv6 subnet addressing plan and benefit from its scalability where this constraint is not required."

That may seem like a logical approach – basically moving everything step-by-step from IPv4 to IPv6 and then expanding once done – but internet backbone engineers who actually build out real-world networks are horrified. One guru broke down his concerns into five bullet points:

  1. The model is inapplicable to real-world networks.
  2. The model will dramatically hinder any further evolution of all IP based networking.
  3. The model carries all legacy problems from IPv4 into the IPv6 era.
  4. The model precludes the application of several of the most basic security measures considered best practice by todays standards.
  5. The model shortens the expected usable life time of IPv6 by at least 25 per cent, or 42-plus years at the current internet growth.

Basically what the ITU is proposing would not only pull over many of the problems associated with IPv4, but would also chew up valuable space making sure that the 1:1 mapping worked. In effect, it would downgrade IPv6 into IPv4+, with the plus simply being more addresses.

Living in the past

"This document seems to have been written with a world view from 2012-2014," complained another engineer who noted that references to transition technologies like 6to4 and Teredo was already out of date.

Another chimed in: "IPv4 suffers from potentially crippling shortages and address allocation optimization requirements for IPv4 bear no relation to sensible and relevant optimization strategies for IPv6. It is extraordinary to see the two conflated in a document like this."

And another: "This plan seems too far removed from operational reality to be really usable. It looks like an academic exercise without operational experience."

Others pointed to a broad range of errors in the document from how address allocation actually works to mistakes made in protocol names and references.

"There are a number of explicit misunderstandings in the document, and they are not small misunderstandings. They will (not might) create operational issues if implemented as explained," warned another.

On top of which, the approach goes directly against fundamental principles decided on by the Internet Engineering Task Force (IETF) and the Internet Architecture Board (IAB) several years ago – a key one of which is even quoted in the document – that future network standards "assume the use of IPv6, and be written so they do not require IPv4."

In effect, the ITU is arguing that because the roads are bad in some countries, every car – from old bangers to modern sports motors – should have their engines pulled out, wheels taken off, and replaced with tractor engines and tires. That way, they will all be able to drive on the road. The engineers, on the other hand, want to lay down new tarmac.

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