[Dnsmasq-discuss] Is empty domain OK?

[Grant Edwards]

On 2022-10-18, William Edwards <wedwards at cyberfusion.nl> wrote:
> Grant Edwards schreef op 2022-10-18 15:50:

>> If there is no domain name for a network, then it seems logical to not
>> use a domain name for that network. Making up a fake one which might
>> later conflict with a real, external, domain seems like the wrong way
>> to go about things.
>
> That's why .local is a reserved TLD.

My understanding was that .local is reserved for use by mDNS. I'm not
using mDNS, and using it in non-mDNS contexts is reported to cause
problems (mostly with Macs?).

>> That's an interesting point. Where does one run into such "hostname
>> validators"?
>
> Anywhere in userland.
>
>>> Would a search domain work for you?
>> 
>> I don't know what you mean by "a search domain".
>
> https://en.wikipedia.org/wiki/Search_domain

OK, I knew about that, but I didn't see how it was relevent to my
questions:

 1. Does dnsmasq support configurations without a local domain name?

 2. Are actual problems created by using such a configuration?

 3. If a local domain name is required, what local domain names are
    officially endorsed for use in a non-residential network that has
    no real, registered domain name?

Multiple people (in other fora) have vaguely stated that you do need a
local domain name, but nobody can point to concrete reasons why. [I
use hostnames without dots all the time, and have never run into a
problem with that.]

I'm leaning towards using 'test' as my local domain. The relevent RFCs
seem to guarantee that it will never collide with a valid TLD. And the
network in question has always been colloquially referred to as "the
test network".

There are other TLDs that are currently reserved and seem to be
popular for this use (e.g. .lan). A handful of others were popular for
this use, but were then proposed as real TLDs (e.g. .home .corp
..mail). Those three appear to have been rejected (with prejudice) as
real TLDs by ICANN — but there still doesn't seem to be any real
approval for using those locally either.

The assumption seems to be that all non-residential networks are going
to have a real, registered, domain name.

Yes, I know I'm obsessing over this and should just pick something
that doesn't currently exist as a valid TLD and get on with it...

--
Grant