[vox-tech] zones and DNS

[ME]

p@dirac.org said:
> hi all,
>
> can someone tell me the difference between a zone and domain?
>
> i've written very basic A, MX and CNAME records a long time
> ago, so i'm still probably a newbie on the subject of DNS.

A Zone is a system for organizating information about a domain and the
services of a domain. A Zone record includes information about how a
domain should be updated, what copy of the zone record is most up-to-date,
and specifics on services for a domain (NS, MX, CNAME, A(-name)) and in
special cases, specify priority for services (MX) when multiple servers
exist.

I look at it like this:
Zone records contain Domain Name information.
Domain Name information does not contain Zone records.
Zone records need not contain Domain Name information.
(localhost, root servers hints file, inaddr-arpa, etc.)

Depending upon how you view a domain, the entire information of a domain
may actually exist across more than one zone record. (Consider the cases
for rDNS and the inaddr-arpa.) Of course, some people do not view this
information as part of the domain, and some others don't even provide
reverse lookup services for their domains.

A really good example of how a Zone File may not be considered part of a
Domain, is when ISP provide Reverse Delegation for rDNS, or provide all
DNS (forward and reverse) for a "classed" network. They may have several
zone files for each domain, but may only have 1 zone file for rDNS.

Another example that is better, is the case with the "hints" file that
contains the list of "root" servers.

Of course, if you are talking NT Domains, then that is another story. ;-)

-ME