Program:  check-aaaa: AAAA response checker
Version:  2.0.0
Authors:  - Shumon Huque <shuque -@- upenn.edu>
          - Joerg Kastning <jkastning -@- my-it-brain.de>

check-aaaa: A small python program to query a set of DNS names
for the presence of AAAA records via a set of DNS recursive
resolvers.

Shumon Huque wrote this quick program on World IPv6 Launch Day (June 6th
2012), after he discovered that some websites were selectively delivering
AAAA records to DNS resolvers, based on measurements by those websites
of the quality of IPv6 connectivity from clients using those resolvers.
Running this program periodically against your own resolvers can
alert you to times when they end up on such AAAA blacklists.

I forked Shumon's project and edited the script to make it run with
Python 3.x. And I added some FQDNs to the list which I like to check
periodically if they return an AAAA record or not.

Pre-requisites:

	Python 3.x
	dnspython module (https://www.dnspython.org/)

Configuration:

    * Edit "check-aaaa" to configure your own list of DNS
      recursive resolvers in the python list RESOLVERS.
    * Write the domains you would like to check in a TXT file
      one domain per line, e.g. 'example.com.'.
      **The dot at the end is important!**
    * Pass the TXT file as an argument to the script
      E.g.: `./check-aaaa domains.txt`

Installation:

    * System wide (typically /usr/bin or /usr/local/bin), as root:

        python setup.py install

    * In your home directory ($HOME/bin):

        python setup.py install --home=$HOME

    * Or just copy the "check-aaaa" file to wherever you want to put it.

Example (hypothetical) runs:

The following example has no output (and a return code of 0)
indicating that all provided names eliciting AAAA reponses via
all provided recursive resolvers.

  $ check-aaaa domains.txt

The following example, shows that one of the resolvers (192.0.2.173)
did not get a AAAA response for www.google.com, while another 
(198.51.100.29) did not get a AAAA response for www.netflix.com.

  $ check-aaaa domains.txt
  resolver1,192.0.2.173 -> www.google.com. not returning AAAA
  resolver2,198.51.100.29 -> www.netflix.com. not returning AAAA


# Copyright (C) 2012, Shumon Huque
# Copyright (C) 2024, Joerg Kastning
#
# check-aaaa is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2, or (at your option)
# any later version.
#
# check-aaaa 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 the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with pydig; see the file COPYING.  If not, write to the Free
# Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
# MA 02110-1301, USA.
#
# Authors: - Shumon Huque <shuque -@- upenn.edu>
#          - Joerg Kastning <jkastning -@- my-it-brain.de>