[IPv6]Re: Analysis of Ungleich ULA Registry

[Lorenzo Colitti <[e-mail]>]

On Thu, May 23, 2024 at 11:36 AM Brian E Carpenter <
[e-mail]> wrote:

> Right. If I want to use fd00:bec0::/32 (BEC being my initials), I
> certainly can, and it will disturb nobody.
>

I believe Jen presented some data a few years ago on what prefixes are in
use, based on backscatter. I don't have the link right now, but I
remember that what emerged from the data is that people did not commonly
use their initials. They commonly used fd00:: or fd01::. In other words,
the chance of collision for human-picked ULA prefixes is very much larger
than for randomly-assigned prefixes.

To use your words... will it "disturb" anyone to pick fd00::? I don't know.
Networks that picked fd00:: will be disturbed if they ever interconnect
with other networks that picked fd00::. Do you thik they are more likely to
try to fix this using renumbering, or via NAT or NPTv6? I'd say the latter.
If they do that, they will disturb application developers and users.

Is it "foolish" to pick fd00::? Well, I would say yes. But the people who
picked it didn't think it was. Or maybe they just didn't know.

I don't have an issue when people make unwise or broken deployment choices.
I just don't like it when people make unwise or broken deployment choices,
and app developers and users end up paying the price. That's not fair.