Reverse lookup problem

[Jane Lemmer]

We are having a reverse lookup problem.  I reviewed some of the messages
is the archive and they helped some, but I'm still not quite clear if the problem
lies with our end, or our ISPs.  I am also not a BIND expert.

We have a Class C network, 198.17.244.x and we run our own DNS locally.
Sometime last week (around April 12), reverse lookups started failing
(i.e., nslookup on 198.17.244.10 returns nothing).  Forward lookups still
work (i.e., nslookup on arclx.reston.carsoninc.com returns 198.17.244.10).

What is confusing to me is that the reverse lookups work fine on hosts
in our address space (i.e. if I'm on the host where the DNS is located,
the reverse lookup works, same if I'm on one of our web servers).

We've contacted our ISP twice and they are saying that since we are
the primary for the IP range, we are responsible for reverse lookup.

But, what I'm not clear on is this:  doesn't someone above us (our
parent, or whatever they are called) have to let the world know that
we are the primary for that IP range?  

Some terminology I've seen is "the ISP needs to delegate the
reverse domain to our server".

I can't seem to ask the right question to the ISP to figure out if this
is the problem or not.

We haven't made any changes to our DNS that I know of that 
might be causing this problem.  We did update our version of
BIND, but that was done March 7.  We also updated one file
to include a new host, but that was done after the problem
manifested.

Any help would be greatly appreciated.  If someone could just
give me a clue as to whether the problem is on our end or
with our ISP, that would be a great help.

Frustrated,

Jane

Jane M. Lemmer
Director
Advanced Research Division
Richard S. Carson & Associates, Inc.
(703) 742-6600
(703) 742-6605 (fax)
lemmerj at reston.carsoninc.com