dlint - Internet Domain Name System (DNS) error checking utility
DNS administrators can use dlint
to scan recursively through the domain
records of the fully-qualified zone zone
, to get a report on any errors
therein. You can scan a zone you own, or anyone else's zone on the Internet.
talks directly to a primary or secondary nameserver for the zone,
to make sure it's working with up-to-date information.
also suggests ways of fixing problems instead of just complaining
about them like other debugging tools.
The argument zone
should always have an ending period to indicate it is a
fully qualified domain name.
By default, dlint
recursively traverses the entire hierarchy below the
zone specified. The -n
option may be used to disable recursive
traversal, causing it to only examine the records in the given zone. Note that
a zone may or may not contain any number of sub-domains (all of which will be
checked with or without this option).
- example% dlint nau.edu.
recursively scans the DNS records in zone nau.edu for problems.
- example% dlint 64.114.134.in-addr.arpa.
recursively scans the DNS records associated with IP subnet 18.104.22.168 for
problems. You had to already know that 22.214.171.124 was subnetted.
The output from dlint
is computer parsable, each line has a special
meaning. Lines beginning with a semicolon (;) are comments only. Lines
beginning with the phrase ``WARNING'' are useful information that you should
consider. A warning is not necessarily an error, but may be a problem. Lines
beginning with the phrase ``ERROR'' are definite errors and should be dealt
- Successful run, no problems encountered with zone.
- Successful run, worst problem with zone was a WARNING.
- Successful run, worst problem with zone was an ERROR.
- Usage error.
- A signal interrupted the program run (i.e. user typed
interrupt key sequence).
doesn't work behind some firewalls because it needs to talk to a
root nameserver to get started.
uses the zone transfer mechanism (AXFR) which some nameservers deny
to unauthorized hosts.
Other nameservers happily return zero records instead of an error, in response
to an unauthorized AXFR! That is just wrong.
Paul Balyoz <firstname.lastname@example.org>
Copyright (C) 1993-1998 Paul A. Balyoz <email@example.com>
This program 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 of the License, or (at your option) any later
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 the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 675 Mass
Ave, Cambridge, MA 02139, USA.