nanog mailing list archives

Re: Recent changes to UltraDNS, problems?


From: Mark Andrews <Mark_Andrews () isc org>
Date: Tue, 24 Aug 2004 11:31:07 +1000 (EST)


In article <412A8369.8000609 () inoc net> you write:

Has anyone else noticed any strange problems lately when querying 
UltraDNS for name server records?

I have a few scripts that seem to have broken in the past week.  A 
simple PERL script that looks up NS records from the root servers, which 
worked fine last week, suddenly starts reporting that the query is 
returning an empty answer.

If I change it to any other TLD servers/domains, it works fine.  What is 
even more strange is that when I use dig, the lookups are just fine. 
(most of the time)  Can anyone at UltraDNS (or anyone else for that 
matter) shed some light on what might have changed/broken?

        There is nothing wrong.  The real NS records for the zone
        can be found in the child zone.  The UltraDNS servers are
        returning a referral to them.

        Also when you are querying authoritative only servers it
        is a good idea to disable recursion.

        Mark

; <<>> DiG 8.3 <<>> ns isc.org @TLD1.ULTRADNS.NET 
; (1 server found)
;; res options: init recurs defnam dnsrch
;; got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 51679
;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 2, ADDITIONAL: 1
;; QUERY SECTION:
;;      isc.org, type = NS, class = IN

;; AUTHORITY SECTION:
isc.org.                1D IN NS        ns1.gnac.com.
isc.org.                1D IN NS        ns-ext.isc.org.

;; ADDITIONAL SECTION:
ns-ext.isc.org.         1D IN A         204.152.184.64

;; Total query time: 431 msec
;; FROM: drugs.dv.isc.org to SERVER: 204.74.112.1
;; WHEN: Tue Aug 24 11:28:40 2004
;; MSG SIZE  sent: 25  rcvd: 95


#!/usr/bin/perl

use strict;
use Net::DNS;    #version 0.48

my @tld = ("tld1.ultradns.net", "tld2.ultradns.net");
my $res = Net::DNS::Resolver->new;
$res->nameservers(@tld);

my $query = $res->query("adaconline.org", "NS");
if($query) {
    print "It worked!\n";
} else {
    print "It failed!\n";
}

exit;



In the above case the query always returns undef and the errorstring 
returned is no error.  My initial thought was a bug in Net::DNS, but 
I've also heard from others they've started noticing strange lookup 
problems when asking UltraDNS directly for answers.

-- 
Robert Blayzor, BOFH
INOC, LLC
rblayzor () inoc net
PGP: http://www.inoc.net/~dev/
Key fingerprint = 1E02 DABE F989 BC03 3DF5  0E93 8D02 9D0B CB1A A7B0

Profanity is the one language all programmers know best.




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