Greetings all,
I have recently become enamoured with Net::DNS, and being able to send and process not only queries, but replies. I have been having good success up until this point, and what appears to me like it should work is, at present, refusing to do so.

I'm attempting to use Net::DNS to complete a step-by-step recursive DNS query, like a "real" DNS server. By this, I'm attempting to take an unknown address to a root nameserver, and then follow the tree of DNS servers down until I get an authoritative answer.
This is not working as I plan, in that when I use Net::DNS to query a root nameserver, instead of returning what I'd expect (a packet with a list of DNS servers to ask next in the 'Authority' section), I get, well, nothing. Net::DNS::Resolver returns an undefined response.
I have traversed the route from root nameserver to the target myself, using 'dig', and everything works - but using Net::DNS, querying the exact same servers, gives me nothing, until I ask the actual authoritative DNS server itself - which, of course, defeats the purpose.
My code is included below to show how I am testing this:

#!/usr/bin/perl -w
use strict;
use Net::DNS::Resolver;
use Net::DNS::Packet;

my $ns = shift(@ARGV);

# New resolver, use the above nameserver
my $res = new Net::DNS::Resolver;
$res->nameservers($ns);

# Run the query
my $res_packet = $res->query("www.slashdot.org");
if (!defined $res_packet) { die("res_packet undefined\n"); }

# Process the returned packet so we can read it
my $d_packet = bless \%{$res_packet}, "Net::DNS::Packet";
if (!defined $d_packet) { die("d_packet undefined\n"); }
print "Packet:\n", $d_packet->string;
[download]

Perhaps there is something about the DNS structure that I don't fully understand?
The route I've taken was using A.ROOT-SERVERS.NET, A.GTLD-SERVERS.NET to NS1.ANDOVER.NET... Or 193.0.14.129, 192.5.6.30, 64.28.67.55.

My thanks in helping me to understand this,
JP

-- Alexander Widdlemouse undid his bellybutton and his bum dropped off --