more bind questions

[Cecil H. Whitley]

Hi,
Some answers and a couple more questions.

> I'm not sure I understand. The next level up is dhs.org. >Since they
aren't running any dns services for me but are >just my domain provider, I
don't see how they fit in.
Name resolution is more of a chain than a direct process.  For example, to
get to your web server from a host ppp01.stuff.com a dns server for
stuff.com would do the following:

query it's root.cache for ns for .org
query .org for ns for dhs.org
query dhs.org for ns for mydomain.dhs.org
query ns.mydomain.dhs.org for the host ip for www.mydomain.dhs.org

Therefore, dhs.org has to run a dns, that's how they provide you a
sub-domain.  Typically they have both an "a" record and a "ns" record for
your dns's.  Everything else for your sub-domain is provided by your own
dns.  However, a nslookup query for www.mydomain.dhs.org sent to ns.dhs.org
should come back with an answer.  Reverse entries however are not that
simple.  The dns entries for those reffering queries to your dns are
typically in the dns of your isp or even their provider.  Reverse entries
work on the ip address and are therefore reffered to the "owner" of that
particular class address for resolution.
Regards,
Cecil