NAME Net::DNS::QueryID - random Query ID numbers SYNOPSIS Functions to manage a cache of random Query ID's for DNS packets. The purpose of this module is to provide and unpredictable source of 16 bit DNS Query ID numbers to help defeat cache poisoning using DNS Spoofing or "Man in the Middle" attacks as describe in the Wikipedia article and its references: http://en.wikipedia.org/wiki/DNS_cache_poisoning use Net::DNS::QueryID qw( id_get id_clr id_busy ); $queryID = id_get(); $result = id_clr($queryID); $result = id_busy($queryID); * $queryID = id_get(); input: none returns: 16 bit integer from 1 - 65535 that is not currently in the cache. false (0) if all 65535 ID's are in use * $result = id_clr($queryID); input: Query ID to clear returns: true (the Query ID) on success false if the Query ID is not in use false if the Query ID is out of range i.e. not 1 -1 65535 * $result = id_busy($queryID); input: Query ID returns: true if Query ID is in the cache false if Query ID is not in the cache false if Query ID is out of range i.e. not 1 -165535 EXPORTS_OK id_get id_clr id_busy AUTHOR Michael Robinton COPYRIGHT 2012-2014 Michael Robinton All rights reserved. This program is free software; you can redistribute it and/or modify it under the terms of either: a) the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version, or b) the "Artistic License" which comes with this distribution. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See either the GNU General Public License or the Artistic License for more details. You should have received a copy of the Artistic License with this distribution, in the file named "Artistic". If not, I'll be glad to provide one. You should also have received a copy of the GNU General Public License along with this program in the file named "Copying". If not, write to the Free Software Foundation, Inc. 59 Temple Place, Suite 330 Boston, MA 02111-1307, USA or visit their web page on the internet at: http://www.gnu.org/copyleft/gpl.html.