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NAME    [Toc]    [Back]

     dig -- send domain name query packets to name servers

SYNOPSIS    [Toc]    [Back]

     dig [@server] domain [<query-type>] [<query-class>] [+<query-option>]
	 [-<dig-option>] [%comment]

DESCRIPTION    [Toc]    [Back]

     Dig (domain information groper) is a flexible command line tool which can
     be used to gather information from the Domain Name System servers.  Dig
     has two modes: simple interactive mode for a single query, and batch mode
     which executes a query for each in a list of several query lines. All
     query options are accessible from the command line.

     The usual simple use of dig will take the form:

		 dig @server domain query-type query-class


     server	 may be either a domain name or a raw (IPv4 / IPv6) Internet
		 address. If this optional field is omitted, dig will attempt
		 to use the default name server for your machine.

		 Note: If a domain name is specified, this will be resolved
		 using the domain name system resolver (i.e., BIND). If your
		 system does not support DNS, you may have to specify a dotnotation
 address.  Alternatively, if there is a server at
		 your disposal somewhere,  all that is required is that
		 /etc/resolv.conf be present and indicate where the default
		 name servers reside,  so that server itself can be resolved.
		 See resolver(5) for information on /etc/resolv.conf.
		 WARNING: Changing /etc/resolv.conf will affect both the standard
 resolver library and (potentially) several programs
		 which use it.	As an option, the user may set the environment
		 variable LOCALRES to name a file which is to be used instead
		 of /etc/resolv.conf (LOCALRES is specific to the dig resolver
		 and is not referenced by the standard resolver).  If the
		 LOCALRES variable is not set or the specified file is not
		 readable, then /etc/resolv.conf will be used.

     domain	 is the domain name for which you are requesting information.
		 See the -x option (documented in the OTHER OPTIONS subsection
		 of this section) for convenient way to specify reverse
		 address query.

     query-type  is the type of information (DNS query type) that you are
		 requesting. If omitted, the default is ``a'' (T_A = address).
		 The following types are recognized:

		 a	 T_A	    network address
		 any	 T_ANY	    all/any information about specified domain
		 mx	 T_MX	    mail exchanger for the domain
		 ns	 T_NS	    name servers
		 soa	 T_SOA	    zone of authority record
		 hinfo	 T_HINFO    host information
		 axfr	 T_AXFR     zone transfer (must ask an authoritative
		 txt	 T_TXT	    arbitrary number of strings

		 (See RFC 1035 for the complete list.)

		 is the network class requested in the query. If omitted, the
		 default is ``in'' (C_IN = Internet).  The following classes
		 are recognized:

		 in	 C_IN	    Internet class domain
		 any	 C_ANY	    all/any class information

		 (See RFC 1035 for the complete list.)

		 Note: ``Any'' can be used to specify a class and/or a type of
		 query.  Dig will parse the first occurrence of ``any'' to
		 mean query-type = T_ANY.  To specify query-class = C_ANY, you
		 must either specify ``any'' twice, or set query-class using
		 the -c option (see below).

   OTHER OPTIONS    [Toc]    [Back]
		 ``%'' is used to included an argument that is simply not
		 parsed.  This may be useful  if running dig in batch mode.
		 Instead of resolving every @server-domain-name in a list of
		 queries, you can avoid the overhead of doing so, and still
		 have the domain name on the command line as a reference.

			     dig @ %venera.isi.edu mx isi.edu

     -<dig option>
		 ``-'' is used to specify an option which affects the operation
 of dig.  The following options are currently available
		 (although not guaranteed to be useful):

		 -x dot-notation-address
			     Convenient form to specify inverse address mapping.
  Instead of ``dig'',
			     one can simply ``dig -x''.

		 -x IPv6-address
			     Convenient form to specify inverse address mapping.
  Instead of ``dig'',
			     one can simply ``dig -x ::1''.

		 -f file     File for dig batch mode. The file contains a list
			     of query specifications ( dig command lines)
			     which are to be executed successively.  Lines
			     beginning with `;', `#', or `\n' are ignored.
			     Other options may still appear on command line,
			     and will be in effect for each batch query.

		 -T time     Time in seconds between start of successive
			     queries when running in batch mode. Can be used
			     to keep two or more batch dig commands running
			     roughly in sync.  Default is zero.

		 -p port     Port number. Query a name server listening to a
			     non-standard port number.	Default is 53.

			     After query returns, execute a ping(8) command
			     for response time comparison.  This rather unelegantly
 makes a call to the shell.	The last three
			     lines of statistics is printed for the command:

					 ping -s -server_name -56 -3

			     If the optional ``ping_string'' is present, it
			     replaces ``ping -s'' in the shell command.

		 -t query-type
			     Specify type of query.  May specify either an
			     integer value to be included in the type field or
			     use the abbreviated mnemonic as discussed above
			     (i.e., mx = T_MX).

		 -c query-class
			     Specify class of query. May specify either an
			     integer value to be included in the class field
			     or use the abbreviated mnemonic as discussed
			     above (i.e., in = C_IN).

		 -k keydir:keyname
			     Sign the query with the TSIG key named keyname
			     that is in the directory keydir.

		 -envsav     This flag specifies that the dig environment
			     (defaults, print options, etc.), after all of the
			     arguments are parsed, should be saved to a file
			     to become the default environment.  This is useful
 if you do not like the standard set of
			     defaults and do not desire to include a large
			     number of options each time dig is used.  The
			     environment consists of resolver state variable
			     flags, timeout, and retries as well as the flags
			     detailing dig output (see below).	If the shell
			     environment variable LOCALDEF is set to the name
			     of a file, this is where the default dig environment
 is saved.  If not, the file ``DiG.env'' is
			     created in the current working directory.

			     Note: LOCALDEF is specific to the dig resolver,
			     and will not affect operation of the standard
			     resolver library.

			     Each time dig is executed, it looks for
			     ``./DiG.env'' or the file specified by the shell
			     environment variable LOCALDEF.  If such file
			     exists and is readable, then the environment is
			     restored from this file before any arguments are

		 -envset     This flag only affects batch query runs. When
			     ``-envset'' is specified on a line in a dig batch
			     file, the dig environment after the arguments are
			     parsed becomes the default environment for the
			     duration of the batch file, or until the next
			     line which specifies ``-envset''.

		 -[no] stick
			     This flag only affects batch query runs.  It
			     specifies that the dig environment (as read initially
 or set by ``-envset'' switch) is to be
			     restored before each query (line) in a dig batch
			     file.  The default ``-nostick'' means that the
			     dig environment does not stick, hence options
			     specified on a single line in a dig batch file
			     will remain in effect for subsequent lines (i.e.
			     they are not restored to the ``sticky'' default).

		 ``+'' is used to specify an option to be changed in the query
		 packet or to change dig output specifics. Many of these are
		 the same parameters accepted by nslookup(8).  If an option
		 requires a parameter, the form is as follows:

			     + keyword [=value]

		 Most keywords can be abbreviated.  Parsing of the ``+''
		 options  is very  simplistic -- a value must not be separated
		 from its keyword by white space. The following keywords are
		 currently available:

		 Keyword      Abbrev.  Meaning [default]

		 [no] debug	(deb)	 turn on/off debugging mode [deb]
		 [no] d2		 turn on/off extra debugging mode
		 [no] recurse	(rec)	 use/don't use recursive lookup [rec]
		 retry=#       (ret)	 set number of retries to # [4]
		 time=#        (ti)	 set timeout length to # seconds [4]
		 [no] ko		 keep open option (implies vc) [noko]
		 [no] vc		 use/don't use virtual circuit [novc]
		 [no] defname	(def)	 use/don't use default domain name
		 [no] search	(sea)	 use/don't use domain search list
		 domain=NAME   (do)	 set default domain name to NAME
		 [no] ignore	(i)	 ignore/don't ignore trunc. errors
		 [no] primary	(pr)	 use/don't use primary server [nopr]
		 [no] aaonly	(aa)	 authoritative query only flag [noaa]
		 [no] cmd		 echo parsed arguments [cmd]
		 [no] stats	(st)	 print query statistics [st]
		 [no] Header	(H)	 print basic header [H]
		 [no] header	(he)	 print header flags [he]
		 [no] ttlid	(tt)	 print TTLs [tt]
		 [no] trunc	(tr)	 truncate origin from names [tr]
		 [no] cl		 print class info [nocl]
		 [no] qr		 print outgoing query [noqr]
		 [no] reply	(rep)	 print reply [rep]
		 [no] ques	(qu)	 print question section [qu]
		 [no] answer	(an)	 print answer section [an]
		 [no] author	(au)	 print authoritative section [au]
		 [no] addit	(ad)	 print additional section [ad]
		 [no] dnssec	(dn)	 set the DNSSEC OK bit in the OPT
					 pseudo record [nodn]
		 pfdef			 set to default print flags
		 pfmin			 set to minimal default print flags
		 pfset=#		 set print flags to # (# can be
		 pfand=#		 bitwise and print flags with #
		 pfor=# 		 bitwise or print flags with #

		 The retry and time options affect the retransmission strategy
		 used by the resolver library when sending datagram queries.
		 The algorithm is as follows:

		       for i = 0 to retry - 1
			   for j = 1 to num_servers
			       wait((time * (2**i)) / num_servers)

		 (Note: dig always uses a value of 1 for ``num_servers''.)

   DETAILS    [Toc]    [Back]
     Dig once required a slightly modified version of the BIND resolver(3)
     library.  As of BIND 4.9, BIND's resolver has been augmented to work
     properly with dig.  Essentially, dig is a straight-forward (albeit not
     pretty) effort of parsing arguments and setting appropriate parameters.
     Dig uses resolver(3) routines res_init(), res_mkquery(), res_send() as
     well as accessing the _res structure.

ENVIRONMENT    [Toc]    [Back]

     LOCALRES	 file to use in place of /etc/resolv.conf
     LOCALDEF	 default environment file

     See also the explanation of the -envsav, -envset, and -[no] stick
     options, above.

FILES    [Toc]    [Back]

     /etc/resolv.conf	 initial domain name and name server addresses
     ./DiG.env		 default save file for default options

SEE ALSO    [Toc]    [Back]

     named(8), resolver(3), resolver(5), nslookup(8).

STANDARDS    [Toc]    [Back]

     RFC 1035.

AUTHOR    [Toc]    [Back]

     Steve Hotz hotz@isi.edu

ACKNOWLEDGMENTS    [Toc]    [Back]

     Dig uses functions from nslookup(8) authored by Andrew Cherenson.

BUGS    [Toc]    [Back]

     Dig has a serious case of "creeping featurism" -- the result of considering
 several potential uses during its development.  It would probably
     benefit from a rigorous diet.  Similarly, the print flags and granularity
     of the items they specify make evident their rather ad hoc genesis.

     Dig does not consistently exit nicely (with appropriate status) when a
     problem occurs somewhere in the resolver (NOTE: most of the common exit
     cases are handled).  This is particularly annoying when running in batch
     mode.  If it exits abnormally (and is not caught), the entire batch
     aborts; when such an event is trapped, dig simply continues with the next

4th Berkeley Distribution	August 30, 1990      4th Berkeley Distribution
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