[vox-tech] zones and DNS

[vox-tech@lists.lugod.org]

On Tue 02 Sep 03,  7:40 AM, ME <dugan@passwall.com> said:
> 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

let me see if i understand you correctly by rephrasing what you said.

for the case of a home user who runs a domain out of his living room
that only offers basic services like www, smtp and ftp, a zone record
is an ecapsulation of all the information needed for the outside world
to access his computer sitting in the living room.  namely, the A, MX
and CNAME records.   here domain and zone records coincide.

but for the more general case, a domain like ibm.com may be broken down
into different zones.  perhaps software.ibm.com and hardware.ibm.com.
a zone record points to the different domain records, and it's these
domain records that contain the A, MX and CNAME records.

is this more or less accurate?

thanks!
pete