Let's Focus on Moving Forward Re: V6 still not supported

John Gilmore gnu at toad.com
Sun Mar 27 01:42:14 UTC 2022

Tom Beecher <beecher at beecher.cc> wrote:
> > */writing/* and */deploying/* the code that will allow the use of 240/4 the
> > way you expect
> While Mr. Chen may have considered that, he has repeatedly hand waved that
> it's 'not that big a deal.', so I don't think he adequately grasps the
> scale of that challenge.

>From multiple years of patching and testing, the IPv4 Unicast Extensions
Project knows that 240/4 ALREADY WORKS in a large fraction of the
Internet.  Including all the Linux servers and desktops, all the Android
phones and tablets, all the MacOS machines, all the iOS phones, many of
the home wifi gateways.  All the Ethernet switches.  And some less
popular stuff like routers from Cisco, Juniper, and OpenWRT.  Most of
these started working A DECADE AGO.  If others grasp the scale of the
challenge better than we do, I'm happy to learn from them.

A traceroute from my machine to goes through six routers at my
ISP before stopping (probably at the first default-route-free router).

Today Google is documenting to its cloud customers that they should use
240/4 for internal networks.  (Read draft-schoen-intarea-unicast-240 for
the citation.)  We have received inquiries from two other huge Internet
companies, which are investigating or already using 240/4 as private
IPv4 address space.

In short, we are actually making it work, and writing a spec for what
already works.  Our detractors are arguing: not that it doesn't work,
but that we should instead seek to accomplish somebody else's goals.


PS: Mr. Abraham Chen's effort is not related to ours.  Our drafts are
agnostic about what 240/4 should be used for after we enable it as
ordinary unicast.  His EzIP overlay network effort is one that I don't
fully understand.  What I do understand is that since his effort uses
240/4 addresses as the outer addresses in IPv4 packets, it couldn't work
without reaching our goal first: allowing any site on the Internet to
send unicast packets to or from and having them arrive.

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