The death of IPv6?

Debunking IPv6

I get somewhat annoyed when people call IPv6  the next generation Internet.  Far from that, IPv6 is a twenty year old failed experiment that people just won’t let go of.

The dominant myth for IPv6 adoption is that the Internet is running out of addresses, and, to be perfectly honest, the only thing IPv6 does offer is more address space. But many argue it’s unnecessary since NATs have been introduced (about a decade ago I guess). And no-one has a compelling reason to go to the expense of adopting it – hence the unbelievably long timeframes.

But couple with this address issue are some significant other ones. The biggest of these, and the subject of much debate in both Internet Architecture Board and the GENI next generation Internet initiative over the last few weeks, is the fact that Ipv6 adoption in parallel with IPv4 (a situation which would exist probably for at least 20 years) will break the routing infrastructure of the Internet.

The problem is serious enough that IAB reps call it urgent. You can get a good analysis here.

The IETF approach is to look for a fix. Nothing emerging to date, but a few ideas.

The GENI approach is to ask “what can we learn from the failure of Ipv6”. Perhaps an easier question, and perhaps the more important one.

Not too many people read both lists. The difference in approach is revealing.

Some seriously respected engineers are even suggesting we abandon IPv6 – many others are saying so quietly but it’s a huge admission for the Internet engineering community to admit this one just ain’t gonna cut it.

A few quotes from here and there over the last week or so:
Jessica Yu:

“The Internet is facing serious scaling problem in its routing system and IPv6, with larger address space but mainly the same routing architecture as IPv4, does not address the issues. With the current routing system, routing aggregation is the only way to make it scalable.
However, Multi-homing makes the aggregation harder.

The sense in the IETF and the operational world is that there is no point to deploy IPv6 until the routing scaling issue got resolved, otherwise IPv6 won’t last long. Changes are needed some in routing architecture in IPv6 to make it more scalable.

The presentation at recent IETF plenary has more information on this issue.”
Deep Mehdi:

“While NAT has provided relief in the IPv4 address space and “delayed”
the need for IPv6, I believe, there is more to it. Note that IPv6 was
designed with a hierarchical addressing structure (sort of similar to
E.164 addressing for telephony), which can be simply stated as a
“provider-dependent” model (using “provider” to mean a  country or an
ISP, and so on). The difficulty with this approach is that it doesn’t
easily allow multi-homing; that is, if you get an IPv6 address block
from an RIR, you cannot home to two different providers. Multihoming has
become a necessity for customers for diversity etc; it that works quite
well in IPv4 because at ‘net-id’ level IPv4 address can be thought of as
based on flat addressing. A related benefit of IPv4 address block (IP
prefix), even without multihoming, is that if as a customer you don’t
like your provider, you can change your provider *without* having to
renumber your network/devices; this isn’t possible in the
provider-dependent IPv6 addressing. IMO, the provider-dependent issue is
one of the key reasons for the ‘non-popularity’ of IPv6 address

Finally, it seems that different addressing will have to live together
in today’s and tomorrow’s networks. I couldn’t have said it better than
Jon Turner when he wrote in an earlier mail:

“We need to move beyond a system in which progress requires universal
agreement. We don’t require universal agreement in any other technology
domain. There is no longer any reason to require it in networking


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