doc man page

doc — diagnose unhealthy DNS domains


doc [-p] [-e][-w][-v][-d] domain_name [parent_domain_name]


Doc is an automated tool for verifying (to an extent) that a domain is configured and functioning correctly. It makes no attempt to validate the data inside a domain, only the structure. The only required parameter is the valid domain name of an existing domain. Example:

doc isi.edu.

Previous versions of doc required that you specify the parent (delegating) domain if it was not precisely one level up from the domain being checked (or specify the parent nameservers in an appropriately named file). Although the option still exists to do that (and it may be required with some complex configurations), some heuristics have been added that make some attempt to handle parent domains that are more than one level up from the current domain. Additional "short-cut" heuristics have been added in the "in-addr.arpa" case. Examples:

doc isi.edu. edu.			(correct, but not required)
doc isi.edu.    			(this works too)
doc 9.128.in-addr.arpa. arpa.	(correct, but not required)
doc 9.128.in-addr.arpa.		(this works too)

If you have problems, giving the parent information information explicitly may help.


Skip testing the information held at delegating domain's servers.

The default operation of doc includes testing that all of the servers for the delegating (parent) domain agree about the delegation information held for the domain in question. Since inconsistencies discovered at this level may or may not indicate serious problems, one can choose to skip the parent testing. If so, doc uses the first non-authoritative list of NS records from a parent domain server as those to direct further queries. If all of the parent domain servers are additionally authoritative for the domain, the answer from the last one queried is used. This may be a useful timesaver if you are regularly checking up on a large number of domains. [See also section Files Used for a similar functionality.]
-[e][w][v][d] Specify the level of verbosity to standard output.

The default mode of operation is to only print to standard output a summary of what is discovered. In addition, errors made in the process of testing (i.e. query errors, errors causing doc to abort, etc) are noted.

  -e	Output comments about errors discovered.
  -w	Output comments about warnings issued.
  -v	Verbose output. Include misc. comments and output
confirming correct behavior.
  -d	Debug output. Checkpoint current (last)
nameserver query.

These output options are cumulative (i.e. -v implies -v -w -e).

NOTE: Parsing is very simple. All option flags must come before the domain names.

Files Created

In addition to the standard output, doc produces a log file named log.<domain_name>, which it places in the .doclogs directory in the users home directory. This file includes all "verbose" level comments, followed by the nameserver responses to the queries (in a slightly masticated form).

While running, doc creates several temporary files in the ~/.doclogs/ directory. These files have names of the form:


Files Used

Doc expects the auxiliary files: doc1.awk, doc3.awk, and doc4.awk to reside in the current libexec directory. This can be overridden by changing the program to look for them in a directory indicated in a shell variable intended for this purpose. If your System Administrator installed doc, they'll need to make the necessary modification.

Doc looks for the file DNsrv.<parent_domain_name> in the working directory. If it exists, doc does not make a standard query to discover the list of nameservers for the parent domain. Rather it queries the list of servers contained in this file to obtain delegation information for the domain being tested. This may be useful if one regularly tests a series of domains, all with the same delegating zone, where one of the servers in known to be foul. This server would simply be omitted from the the DNsrv.* file.

awk, sed & dig (version 2.0 or higher) are expected to be found in your normal path. If not, you may want to alias to the full path inside of doc itself.


See file Info (included with distribution tar) for details of procedure.


The exit code returned via the shell is only 8 bits. This could cause a problem in the value returned by the auxiliary file doc3.awk. This hasn't been seen yet (a "poison configuration" is not likely to occur yet), and hopefully will be corrected if/when doc is re-implemented (see below).

The current implementation is fairly simple (albeit not pretty), so it is not expected to abort unexpectedly. However, this version (2.0) is an initial attempt at automating this task. Further development is expected in identifying the appropriate queries, analysis, and subsequent conclusions that are made. Hopefully once the design of the test suite has become more stable, a less "patchwork" production version of doc will be done.


The previous authors effectively stopped further development and support in 1990. Starting with version 2.1, the official anonymous FTP site for doc is ftp.vix.com as part of the the latest distribution of BIND (see the BIND Home Page at <URL:http://www.isc.org/isc/>). It will also be separately available in the DNS Resources Directory <URL:http://www.is.co.za/andras/computer/dns…>.

Relatively minor modifications have been made with version 2.1, mostly to make the program a bit more robust in handling parent (delegating) domains.

This program is being shared with the rest of the Internet on a unsupported basis. If you have any enhancements or changes you have made, please let me know. I'd love to see them, with an eye towards integrating them into my version (and also into the publicly available version). However, keep in mind that I'm not getting paid (nor do I have the time) to support the whole Internet on this tool.

Now that I have changed employers, and I am going to be involved in writing all sorts of administrative tools for our internal use, I intend to use doc and some other programs as "excuses" to learn Perl and Tcl/Tk. I hope to make these updated version publicly available, but I have yet to get formal approval for that. I will make available whatever I can, likely through the URLs provided above, and through related URLs that will be widely publicized.


The name doc comes from Domain Obscenity Control, in that the kinds of structure problems it looks for are considered "obscene" from the perspective of a well-managed DNS.

To Do

RFC 1537 SOA value conformance checking (warnings only).

Previous Authors

Steve Hotz (hotz@isi.edu) Paul Mockapetris (pvm@isi.edu)

Modifications by

Brad Knowles (BKnowles@aol.net)

See Also

dig(1), bind operators guide (BOG), RFCs: 1034,1035,1535-1537,1713,xxxx


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