sourCEntral - mobile manpages

pdf

Net::DNS::Resolver::Recurse

NAME

Net::DNS::Resolver::Recurse − Perform recursive dns lookups

SYNOPSIS

  use Net::DNS::Resolver::Recurse;
  my $res = Net::DNS::Resolver::Recurse−>new;

DESCRIPTION

This module is a sub class of Net::DNS::Resolver. So the methods for Net::DNS::Resolver still work for this module as well. There are just a couple methods added:

hints
Initialize the hint servers. Recursive queries need a starting name server to work off of. This method takes a list of IP addresses to use as the starting servers. These name servers should be authoritative for the root (.) zone.

  $res−>hints(@ips);

If no hints are passed, the default nameserver is asked for the hints. Normally these IPs can be obtained from the following location:

  ftp://ftp.internic.net/domain/named.root

recursion_callback
This method is takes a code reference, which is then invoked each time a packet is received during the recursive lookup. For example to emulate dig’s "+trace" function:

 $res−>recursion_callback(sub {
     my $packet = shift;
     $_−>print for $packet−>additional;
     printf(";; Received %d bytes from %s\n\n",
         $packet−>answersize,
         $packet−>answerfrom
     );
 });

query_dorecursion
This method is much like the normal query() method except it disables the recurse flag in the packet and explicitly performs the recursion.

  $packet = $res−>query_dorecursion( "www.netscape.com.", "A");

IPv6 transport

If the appropriate IPv6 libraries are installed the recursive resolver will randomly choose between IPv6 and IPv4 addresses of the nameservers it encounters during recursion.

If you want to force IPv4 transport use the force_v4() method. Also see the IPv6 transport notes in the Net::DNS::Resolver documentation.

AUTHOR

Rob Brown, bbb AT cpan DOT org

SEE ALSO

Net::DNS::Resolver,

COPYRIGHT

Copyright (c) 2002, Rob Brown. All rights reserved. Portions Copyright (c) 2005, Olaf M Kolkman.

This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

$Id: Recurse.pm 740 2008−12−17 23:20:53Z olaf $

pdf