Re: DNS and subdomains

[Stephane Bortzmeyer via NANOG <nanog () nanog org>]

On Mon, Feb 24, 2025 at 08:58:48PM -0500,
 Harry Hoffman via NANOG <nanog () nanog org> wrote 
 a message of 195 lines which said:

> Has this become common practice? Is there a definitive way to determine
> subdomains? I seem to recall that "older" dns server software wouldn't
> allow this but it could be that my memory is faulty.

You already got three excellent replies but I may add that there *was*
an attempt at IETF to design a way to find administrative boundaries
in the DNS but it basically failed:

https://mailarchive.ietf.org/arch/msg/dbound/F9SkNAZmYHGKlRwbn5Il78pOkFs/
https://datatracker.ietf.org/doc/draft-sullivan-dbound-problem-statement/
https://datatracker.ietf.org/wg/dbound/

My favorite example, when I lecture on DNS, is gouv.fr (no zone cut
between gouv.fr and fr but it is administratively distinct).