In the DNS hierarhy you have Top Level Domanis (TLD) in the root zone (like .com, .net and in our case .org). Then you have 'ampr' as single domain.
All entries resolvable directly to an host IP in 'ampr' are in this domain and are not delegated. e.g. yo2loj.ampr.org (44.182.20.36).
If I would set up a subdomain, I would have different machines with different IPS under yo2loj.ampr.org, an that would be a subdomain. e.g. mail.yo2loj.ampr.org, www.yo2loj.ampr.org, ftp.yo2loj.ampr.org, ns.yo2loj.ampr.org and so on. In that case, name resolutions could be delegated for all *.yo2loj.ampr.org names to lets say ns.yo2loj.ampr.org and I would need to maintain my own DNS server(s).
That means that in a DNS resolution there would be 2 lookups, first one to the ampr.org NS to get my NS as defined there, and a second lookup to my local NS to resolve that name. And it also means that if my NS is down, resolution will not be possible.
Now if one uses a single <callsign>.ampr.org with one IP, this is resolved directly at ampr.org level, avoiding both issues, but keeping the name resolution out of his hands.
Marius, YO2LOJ
-----Original Message----- From: 44net-bounces+marius=yo2loj.ro@hamradio.ucsd.edu [mailto:44net-bounces+marius=yo2loj.ro@hamradio.ucsd.edu] On Behalf Of Pedja YT9TP Sent: Friday, May 29, 2015 22:43 To: AMPRNet working group Subject: Re: [44net] Bad MX records in the ampr.org DNS
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Can you point out of some sample of domain usage which is not subdomain?
Pedja YT9TP