Re: Strange DNS resolving behavior

Hi,

Your nameserver (148.85.1.1) resolves fine both forward and reverse from
here when I do a lookup for amherst.publishingconcepts.com. No timeouts -
looks normal.

HTH

On 21 Apr 2004 at 10:31, John Manly wrote:
Subject: Strange DNS resolving behavior
Date sent: Wed, 21 Apr 2004 10:31:47 -0400
From: "John Manly" <jwmanly@amherst.edu>
To: <bind-users@isc.org>

> Greetings, all. I'm experiencing a strange problem with DNS resolving
> that I'm hoping someone can shed some light on. A vendor that we work
> with has set up a DNS name in their domain,
> "amherst.publishingconcepts.com" as an A record with an IP address of
> 12.156.3.83. However, my site's DNS servers (and one other ISP's DNS
> servers that I can find) for some reason cannot resolve this address.
> But every other DNS server that I've tried querying can resolve the
> address. Further, the problem appears to be specific to this particular
> name -- other A records in the same domain (such as
> www.publishingconcepts.com or tigernet.publishingconcepts.com) resolve
> properly. I have no idea where to start looking for a solution (or even
> an explanation of this.)
>
> Below are the results of some of my NSLOOKUP attempts to my own
> nameserver, as well as those of Genuity/Level3 (the other set of DNS
> servers that appear to be unable to resolve the name), and then a bunch
> from DNS servers that appear to work properly.
>
> First, here are three tests against my own name server. The problematic
> name produces a timeout, but another name within the same domain that I
> know is valid works properly, and an attempt to translate a name that I
> know doesn't exist gives the expected error result (but not a timeout).
>
>
> $ nslookup -q=3DA amherst.publishingconcepts.com 148.85.1.1 # My
> nameserver
> ;; connection timed out; no servers could be reached # Timeout
> response
>
>
> $ nslookup -q=3DA www.publishingconcepts.com 148.85.1.1 # My
> nameserver, trying another name
> Server: 148.85.1.1
> Address: 148.85.1.1#53
> Non-authoritative answer:
> Name: www.publishingconcepts.com=20
> Address: 12.156.3.116 # Looks like
> it worked properly
>
>
> $ nslookup -q=3DA foo.publishingconcepts.com 148.85.1.1 # My
> nameserver, a name I know doesn't exist
> Server: 148.85.1.1
> Address: 148.85.1.1#53
> ** server can't find foo.publishingconcepts.com: NXDOMAIN # The
> expected error, not a timeout
>
>
> Next, here are a series of NSLOOKUPs of the problematic name against a
> series of other name servers, all of which appear to work fine:
>
>
> $ nslookup amherst.publishingconcepts.com 138.110.1.1 # Mount
> Holyoke College
> Server: 138.110.1.1
> Address: 138.110.1.1#53
> Non-authoritative answer:
> Name: amherst.publishingconcepts.com
> Address: 12.156.3.83 # <------------------------------- Correct
> answer
>
>
> $ nslookup amherst.publishingconcepts.com 128.119.166.8 # University
> of Mass
> Server: 128.119.166.8
> Address: 128.119.166.8#53
> Non-authoritative answer:
> Name: amherst.publishingconcepts.com
> Address: 12.156.3.83 # <------------------------------- Correct
> answer
>
>
> $ nslookup amherst.publishingconcepts.com 151.202.0.68 # Verizon New
> York DNS
> Server: 151.202.0.68
> Address: 151.202.0.68#53
> Non-authoritative answer:
> Name: amherst.publishingconcepts.com
> Address: 12.156.3.83 # <------------------------------- Correct
> answer
>
>
> $ nslookup amherst.publishingconcepts.com 199.45.45.14 # Verizon
> Washington DC DNS
> Server: 199.45.45.14
> Address: 199.45.45.14#53
> Non-authoritative answer:
> Name: amherst.publishingconcepts.com
> Address: 12.156.3.83 # <------------------------------- Correct
> answer
>
>
> $ nslookup amherst.publishingconcepts.com 192.9.9.3 # Sun
> Microsystems
> Server: 192.9.9.3
> Address: 192.9.9.3#53
> Non-authoritative answer:
> Name: amherst.publishingconcepts.com
> Address: 12.156.3.83 # <------------------------------- Correct
> answer
>
>
> $ nslookup amherst.publishingconcepts.com 207.217.126.41 # Earthlink
> Server: 207.217.126.41
> Address: 207.217.126.41#53
> Non-authoritative answer:
> Name: amherst.publishingconcepts.com
> Address: 12.156.3.83 # <------------------------------- Correct
> answer
>
>
> Finally, I ask Genuity/Level3's name servers. Genuity/Level3 acts
> provides secondary name service for our domains. In one case it reports
> the domain or name isn't valid, and in another it times out just like my
> own nameserver does. But again, when I look up a name within the
> publishingconcepts.com domain that I know doesn't exist, I get a
> different kind of error (the expected error) back:
>
>
> $ nslookup amherst.publishingconcepts.com 4.2.49.3 #
> Genuity/Level3
> Server: 4.2.49.3
> Address: 4.2.49.3#53
> Non-authoritative answer:
> *** Can't find amherst.publishingconcepts.com: No answer # WRONG ANSER
>
>
> $ nslookup -q=3DA amherst.publishingconcepts.com 4.2.2.1 # Another
> Genuity/Level3 server
> ;; connection timed out; no servers could be reached # No answer
> at all (timeout)
>
>
> $ nslookup -q=3DA foo.publishingconcepts.com 4.2.2.1 #
> Genuity/Level3 ISP DNS server
> Server: 4.2.2.1
> Address: 4.2.2.1#53
> ** server can't find foo.publishingconcepts.com: NXDOMAIN # NXDOMAIN
> (no such name)
>
> So, I'm completely stumped as to what is going on here. Somehow this
> particular name "amherst.publishingconcepts.com" is not resolving via
> some DNS servers, specifically mine. But other names in the
> publishingconcepts.com domain are resolving properly, and the error that
> the above DNS name yields is different from the name simply being
> missing.
>
> Any light that anyone can shed, or directions that anyone can sugggest
> for further debugging/troubleshooting/investigation on this issue would
> be most helpful.
>
> -- John W. Manly <jwmanly@amherst.edu>
> Systems and Networking, Amherst College
>
>