John, On Nov 18, 2021, at 12:54 PM, John Gilmore <gnu@toad.com> wrote:
Is it even *doable*?
With enough thrust, pigs fly quite well, although the landing can be messy.
What's the *risk*?
Some (not me) might argue it could (further) hamper IPv6 deployment by diverting limited resources.
What will it *cost* to upgrade every node on the Internet? And *how long* might it take?
These are the pertinent questions, which are, of course extremely hard to estimate.
We succeeded in upgrading every end-node and every router in the Internet in the late '90s and early 2000's, when we deployed CIDR.
My recollection was that CIDR deployment was a bit early than that, but regardless, the Internet of the late '90s and early 2000’s was vastly different than the Internet today. For one thing, most of the end nodes still had people with technical clue managing them. That’s not the case today.
So today if we decide that unicast use of the 268 million addresses in 240/4 is worth doing, we can upgrade every node.
Can we? We can’t even get some DNS resolvers to stop querying root server IP addresses that were renumbered two decades ago. People aren’t even patching/updating publicly available systems with active security exploits that are impacting them directly and you believe they’ll be willing to update all their devices to benefit other people (the ones who want the 240/4 space)? You must be more optimistic than I. Regards, -drc