Looking for DNS tracing tool

David Botham dns at botham.net
Fri Jul 12 19:03:23 UTC 2002




> -----Original Message-----
> From: bind-users-bounce at isc.org [mailto:bind-users-bounce at isc.org] On
> Behalf Of phil-news-nospam at ipal.net
> Sent: Friday, July 12, 2002 1:12 AM
> To: comp-protocols-dns-bind at isc.org
> Subject: Looking for DNS tracing tool
> 
> I'm looking for a DNS tracing tool that doesn't stop and NS records,
> but follows through and completes the trace, not only following
> delegations all the way, but also getting the final record and show
> it, PLUS, if it is a CNAME and something other than CNAME was
requested,
> it should follow the CNAME as well, exactly like any recursive lookup
> would do, and shows everything down to the final record, including it.
> So if I'm doing a A record lookup for a name which has a couple of
CNAME
> references, it will follow through both CNAME references and give the
> final A record (and everything in between).  Basically it would be a
> full recursive trace.

I could be wrong about this, but, if you look up an A record, there is
no way to also find CNAME records that reference that A record.  I think
this will not work because domain names are only index on the "left"
side of the RR.  In other words, how would you know if www.domain.com
was on the Right side of these records by looking up www.domain.com?:

www.domain.com.		A	192.168.1.10

ftp.domain.com		CNAME	www.doamin.com.
gopher.domain.com.	CNAME	www.domain.com.


In other words, the information you are looking for is not really in the
DNS...

Dave...

> 
> I've tried "dig +trace" and a program called dnstracer, but both of
> the stop at the last name server and won't finish, and both fail to
> follow a CNAME.
> 
> An added plus, which dnstracer can do somewhat, is to do a "full
spread"
> recursion, where ever reference is followed through at every level,
even
> if they go different ways.  For example, every name server is queried
> for multiple NS records.  And if those servers have different data
that
> would recurse in different directions, all of them would be followed.
> 
> It would also be nice if it encounters obvious errors, to note the
errors
> and keep on working.
> 
> Another added plus would be to follow PTR records to corresponding A
> recors.
> 
> --
> -----------------------------------------------------------------
> | Phil Howard - KA9WGN |   Dallas   | http://linuxhomepage.com/ |
> | phil-nospam at ipal.net | Texas, USA | http://phil.ipal.org/     |
> -----------------------------------------------------------------



More information about the bind-users mailing list