Introduction
------------

This is DDT, Domain Debug Tools, version 2.0, a package to debug the
DNS tree.

DDT is a package to help zone administrators to avoid as much as possible these
problems, providing a set of commands to analyze any portion of the DNS tree.

DDT works on cached data because, as such, it can be reasonably efficient.  A 
command (ddt-xfer) is available to try to cache the "real world" situation as 
close as possible.  This command is a slightly modified version of named-xfer,
that transfers a zone to the cache and, optionally, all its descendents zones.
See ddt(1) for details.

Given its philosophy, DDT is fatser than if it would be constantly querying 
servers on-line, as it doesn't rely on available bandwith or line speed 
(caching may be done in the background or overnigh, retrying any failed 
transfer); you only have to worry about disk space.  As such, it is suited for
analizyng large quantities of data, as is the case of NOCs and top-level 
domains (togehter with their children).

You must have dig installed in order to run one of the commands (soac).  We 
hope to eliminate this need in a future release, by using some perl library to 
do what dig does now.  Thanks to David Barr <barr@pop.psu.edu> we have bind.pl
to start playing with.

DDT 2.0 is entirely written in perl, which means we had to completely rewrite
DDT 1.0, which was written in GNU awk.  The decision to change was taken after
querying JABPH (Just Another Bunch of Perl Hackers), from comp.lang.perl, about
the virtues of perl.

Both perl and dig can be found almost anywhere, and we can't recommend THE
site to get them.


Changes
-------

Most probably you haven't heard of DDT before, since the world wasn't too much
told about it (not so true any more, since Paul Vixie included some info in the
contrib/misc directory of BIND 4.9), so it doesn't make much sense listing the 
differences between 1.0 and 2.0.  You only have to believe :-) that 2.0 does 
a more complete set of tests over DNS data, and it is, in general, a bit 
faster.


Installation
------------

The procedure is very simple, you only have to edit conf/config and tailor it
according to your choices.  After that run ./build and all the work will be
done for you.


Contents
--------

	Makefile	    - as expected
	README		    - you are doing it
	SOA-timers.template - a template for a table of recommended SOA timers
	build		    - a script to do all the installation
	cmd		    - the commands to play with
	conf		    - configuration data
	doc		    - TeX sources for a paper about DDT
	man		    - man pages
	xfer		    - sources for ddt-xfer


Whish list
----------

DDT 2.1 will (eventually :-):

	- get rid of dig (as stated above)	
	- mxc should care only for MXs for the analised zone
	- rrc should consider all kinds of RRs
	- rrc must take into account changes introduced by RFC 1101
	- include a report generator
	- perhaps improve ddt-xfer - we'll take a look at 4.9 named-xfer
	- ... (anything else we can think about)

Please report all bugs, comments, requests for features, etc to frazao@puug.pt 
and/or artur@dns.pt

Enjoy!

	Jorge Frazao
	Artur Romao
