finding out parent DNS of local DNS or local forwarder (provided FQDN is not defined)

[Vishwas]

Hello Adam and Kevin,

Adam:
+trace option gives me the list of DNSes placed between ROOT DNS and
local DNS. Thanks.

Kevin:
Am sorry for using the term "parent" without thinking about its
possible interpretations. What I meant by using the term "parent DNS"
was -- A parent DNS is a DNS that serves its subordinate forwarding
DNSes. As you know, in some networks local DNS is nothing but a
forwarder and forwards all incoming queries to another DNS - which I
called parent DNS (in my previous mail, attached below). And such a
parent DNS need not be part of the name-authority-delegation hierarchy
of the local DNS. That is, a forwarder of domain example.com can
forward its DNS queries to dns.ISP.com. Provided, ISP.com intended so.

I want to find out how many DNS servers are there over the Internet
and how they are placed, and connected to each other. As Kevin points
out, its not a reliable (though partially useful) way to start with a
FQDN and traverse the authoritative DNS tree downwards. Another
concrete way is to rely only on IP addresses and traverse the DNS tree
upwards with +trace option. But the problem with this IP based
approach is that I may not be able fire the requests (dig @x y +trace)
from all the domains of the Internet.

In near future I would like to obtain all possible details of DNSes
over the Internet and make a graph representing connections among
DNSes. But do you people think there can be a time bound method to
make DNS topology. At present, my feeling is that to obtain the list
of all visible DNSes over the Internet and their details, a mix of
approaches will be required. I have come across previous such efforts
but the statistics is somewhat stale now. Any suggestions or comments
are very much welcome.

kind regards,
Vishwas.

On 6/5/07, Kevin Darcy <kcd at daimlerchrysler.com> wrote:
> Vishwas wrote:
> > Hello, (sorry for the previous mail with incomplete info.)
> >
> > 1. What is the way to find out the parent DNS of local DNS server? I
> > have no access to the local DNS, except port 53. And the local network
> > has not been registered with any DNS.
> >
> > 2. If there is a way to find out parent DNS of local DNS, can I trace
> > all the DNSes until the root server?
> >
> >
> Delegations go "down", not "up". Although you can trace a delegation
> chain for a particular zone down from the root to (potentially) a
> particular nameserver, there's no good, reliable way to start with the
> name of a particular nameserver, and find all of the delegations that
> point to it.
>
> Is that what you meant? Or did you have some other definition of
> "parent", in the DNS context?
>
>
>                               -Kevin
>
>
>


-- 
Best Regards,
Vishwas.
ivishwas.googlepages.com

He gives twice who gives quickly.  --  Publisus Mimus