Tom Beecher <beecher@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 240.1.2.3 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. John 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 240.0.0.1 and having them arrive.