dot internal and mDNS

[George at Clug]

I believe ICCAN are moving to possibly replacing .local, .home, .lan,
.corp, .mail, .localdomain, (and possibly others) with .internal ?


How could this affect mDNS and the use of .local?


https://www.icann.org/en/public-comment/proceeding/proposed-top-level-domain-string-for-private-use-24-01-2024
Staff have assessed that there have been no responses that would cause
them to view the analysis as erroneous or to require re-assessment or
a different conclusion. Therefore the proposed selection (.INTERNAL),
along with the outcome of the public comment proceeding, will be
presented to the ICANN Board for further consideration.

https://icannwiki.org/Name_Collision
ICANN deemed two strings, .home and .corp, as "high-risk" because of
the widespread use of the terms on internal networks. Currently, ICANN
is indefinitely delaying the delegation of these string to the root.
Public Comments
      2. Case Studies of Collision Strings (.corp, .home, .mail,
.internal, .lan, and .local) based on DNS query data from A and J root
servers in light of DNS evolution.


https://www.icann.org/en/system/files/files/name-collision-mitigation-01aug14-en.pdf
ICANN has stated that it will indefinitely defer delegating three
TLDs: .corp, .home, and .mail. These
gTLDs are still in common use in private namespaces, and thus pose a
significantly higher risk for
collisions than other TLDs. The deferral is not guaranteed to be
forever, so any organization using one
of those names as a private namespace should still follow the
directions in Section 4 or Section 5 for
migrating from the private namespace.


https://www.icann.org/en/system/files/files/name-collision-mitigation-01aug14-en.pdf


https://www.theregister.com/2024/01/29/icann_internal_tld/


https://datatracker.ietf.org/doc/html/rfc6762
   Using ".local" as a private top-level domain conflicts with
Multicast DNS and may cause problems for users.


https://itp.cdn.icann.org/en/files/security-and-stability-advisory-committee-ssac-reports/sac-113-en.pdf

https://wiki.archlinux.org/title/Systemd-resolved

https://www.freedesktop.org/software/systemd/man/latest/nss-resolve.html

[jeremy ardley]

Post by George at Clug
I believe ICCAN are moving to possibly replacing .local, .home, .lan,
.corp, .mail, .localdomain, (and possibly others) with .internal ?

I read the ICANN documents you referenced but did not see the proposal
was to replace those domains? It is more offered as a recognised TLD
that is preferred for use.

The above domains are not recognised and are seen as potentially
dangerous. Hence the proposal

The presently recognised non-routable TLDs are

.local (special case for mDNS)
.localhost (no to be confused with localhost)
.invalid
.test

The recognised non routed second level domain is

.home.arpa

[Andy Smith]

Hi,

Post by George at Clug
I believe ICCAN are moving to possibly replacing .local, .home, .lan,
.corp, .mail, .localdomain, (and possibly others) with .internal ?

home.arpa was defined by IANA in 2018. If they go ahead with
.internal then I can only imagine it will be in addition to, not
instead of, home.arpa.

Post by George at Clug
How could this affect mDNS and the use of .local?

It won't. mDNS will continue using .local.

If you use .local for other things it can interfere with mDNS but
picking almost anything else has very few repercussions (unless you
are very silly about it), so I don't understand why this topic
always generates so much debate on this list.

Thanks,
Andy

[Michael Kjörling]

Post by Andy Smith

Post by George at Clug
I believe ICCAN are moving to possibly replacing .local, .home, .lan,
.corp, .mail, .localdomain, (and possibly others) with .internal ?

home.arpa was defined by IANA in 2018. If they go ahead with
.internal then I can only imagine it will be in addition to, not
instead of, home.arpa.

The initial version of the relevant Internet Draft (as published Aug
2) doesn't even mention home.arpa, which seems like an oversight as
the intended use is very similar. Hopefully that will be corrected
before publication as a RFC.

https://www.icann.org/en/board-activities-and-meetings/materials/approved-resolutions-special-meeting-of-the-icann-board-29-07-2024-en#section2.a

https://datatracker.ietf.org/doc/draft-davies-internal-tld/

https://www.ietf.org/archive/id/draft-davies-internal-tld-00.txt

.home was _specifically_ for HNCP (see RFC 7788; just as .local is
_specifically_ for mDNS) and RFC 7788 was updated by RFC 8375 (the
reservation of .home.arpa) to use the more generic .home.arpa as a
default.

Assuming that there are no late showstoppers for the reservation of
.internal, we will going forward have two officially recommended
choices for where to place internal, non-unique hostnames; namely
*.internal and *.home.arpa. The third alternative is to register a
globally unique domain name and use that as the root for one's
internal DNS names; doing so guarantees global uniqueness in DNS for
the fully qualified names.