On Mon, Dec 27, 2004 at 08:08:32PM -0800, william(at)elan.net wrote:
> You talk about DNS domains as a group of records. I think this is
> not correct.
> In "inmail-backup1.elan.net", this entire name is a DNS domain,
> so are "inmail-backup2.elan.net" and "inmail-backup3.elan.net".
> The way you describe it, the domain would be "elan.net".
> DNS ZONE has a similar problem.
DNS domains are in fact groups of HOST records and DOMAIN is something
that has been delegated within DNS hierarchy (i.e. its what is pointed
Again: I think you are confusing zones, domains and other related
stuff. If you are going to present it as a fact sheet, make sure
you get it right.
You are describing a ZONE and are calling it a domain. That in
itself is not wrong, because a zone _is_ a domain. However, it
is not true that a domain must be a group of hosts.
inmail-backup1.elan.net is ALSO a domain.
Zones are where delegation occurs. This is part of the DNS-tree
that is delegated to another authority, it has a SOA record.
Starting somewhere inside the DNS-tree, follow the entire path
upto the root and concatenate every LABEL you find (separated
by dots) to get a domain.
A hostname is just one kind of domain.
A hostname is always a domain; domain is not always a hostname
See rfc 1035, section 3.1 (and the rest of the doc)