One thing is for certain… If folks had put 0.10 as much effort into deploying IPv6 as has been put into arguing about whether or not ~17 /8s worth of IPv4 makes a meaningful difference to the internet as a whole, IPv4 would long since have become irrelevant as it must eventually be. Owen
On Mar 8, 2022, at 18:35, Seth David Schoen <schoen@loyalty.org> wrote:
John R. Levine writes:
This still doesn't mean that screwing around with 240/4 or, an even worse 127/8 minus 127/24, is a good idea.
I hope you'll be slightly mollified to learn that it's actually 127/8 minus 127/16.
https://datatracker.ietf.org/doc/draft-schoen-intarea-unicast-127/
That's the most challenging one, but we've still seen something of a lack of people getting in touch to point out concrete problems.
One person did get in touch to describe an unofficial use of, apparently, all of 127/8 as private address space in a VPN product. If people let us know about more, we can investigate workarounds or possible changes to our proposals.
We previously thought that the reference NTP implementation was using all of 127/8 to identify hardware clock drivers. But it turns out it doesn't actually connect to these.
If anyone reading this knows of something that uses a loopback address outside of 127/16 for an application, or something that can't be updated and would be harmed if the rest of the network stopped treating this as loopback, we'd be glad to hear about it.