dig(1)                     OpenBSD Reference Manual                     dig(1)

NAME
     dig - send domain name query packets to name servers



SYNOPSIS
     dig [@server] domain [query-type] [query-class] [-f file] [-T time] [-p
         port] [-P[ping-string]] [-t query-type] [-c query-class] [-envsav]
         [-envset] [-stick | -nostick] [+keyword[=value]] [%comment]
     dig [@server] -x dot-notation-address [...]

DESCRIPTION
     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 which makes a single query, and
     batch 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
     where:

     server       may be either a domain name or a dot-notation Internet ad-
                  dress. 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 dot-
                  notation 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 resolv.conf(5) for information on /etc/resolv.conf.

                  Warning: Changing /etc/resolv.conf will affect 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 not referenced by the standard resolver). If the
                  LOCALRES variable is not set or the file is not readable
                  then /etc/resolv.conf will be used.

     domain       is the domain name for which you are requesting information.
                  See OTHER OPTIONS (-x) for a convenient way to specify in-
                  verse address query.

     query-type   is the type of information (DNS query type) that you are re-
                  questing. 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 server)
                  txt    T_TXT    arbitrary number of strings



                  (See RFC 1035 for the complete list.)

     query-class  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
                  -c option (see below).

OTHER OPTIONS
     %ignored-comment
                   ``%'' 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.
                   Example:
                         dig @128.9.0.32 %venera.isi.edu mx isi.edu

     -x dot-notation-address
                   Convenient form to specify inverse address mapping.  In-
                   stead of
                         dig 32.0.9.128.in-addr.arpa
                   one can simply
                         dig -x 128.9.0.32

     -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 ze-
                   ro.

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

     -P[ping-string]
                   After query returns, execute a ping(1) command for response
                   time comparison. This rather inelegantly makes a call to
                   the shell. The last three lines of statistics are 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 the type of query. This may specify either an inte-
                   ger value to be included in the type field or use the ab-
                   breviated mnemonic as discussed above (i.e., mx = T_MX).

     -c query-class
                   Specify the class of query. This may specify either an in-
                   teger value to be included in the class field or use the

                   abbreviated mnemonic as discussed above (i.e., in = C_IN).

     -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 en-
                   vironment.  Useful if you do not like the standard set of
                   defaults and do not desire to include a large number of op-
                   tions 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 int the
                   working directory, or the file specified by the shell envi-
                   ronment variable LOCALDEF. If the file exists and is read-
                   able, then the environment is restored from it before any
                   arguments are parsed.

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

     -stick | -nostick
                   These flags only affects batch query runs.  -stick speci-
                   fies 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; that is, 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).

     +keyword[=value]
                   ``+'' 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).

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

                   Keyword      Abbrev. Meaning [default]

                   [no]debug    (deb)   turn on/off debugging mode [deb]
                   [no]d2               turn on/off extra debugging mode [nod2]
                   [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 [def]
                   [no]search   (sea)   use/don't use domain search list [sea]
                   domain=NAME  (do)    set default domain name to NAME
                   [no]ignore   (i)     ignore/don't ignore trunc. errors [noi]
                   [no]primary  (pr)     use/don't use primary server [nopr]
                   [no]aaonly   (aa)    authoritative query only flag [noaa]
                   [no]sort     (sor)   sort resource records [nosor]
                   [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]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]
                   pfdef                set to default print flags
                   pfmin                set to minimal default print flags
                   pfset=#              set print flags to #
                                        (# can be hex/octal/decimal)
                   pfand=#              bitwise and print flags with #
                   pfor=#               bitwise or print flags with #

                   The keywordfile ...  and time keywords affect the retrans-
                   mission strategy used by resolver library when sending
                   datagram queries. The algorithm is as follows:

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

                   Note: dig always uses a value of 1 for num_servers.

DETAILS
     dig once required a slightly modified version of the BIND resolver(3) li-
     brary. BIND's resolver has (as of BIND 4.9) been augmented to work prop-
     erly with dig. Essentially, dig is a straight-forward (albeit not pretty)
     effort of parsing arguments and setting appropriate parameters.  dig uses
     resolver routines res_init(), res_mkquery(), res_send() as well as ac-
     cessing the _res structure.

FILES
           /etc/resolv.conf                  initial domain name and name
                                             server addresses
           DiG.env                           default save file for default op-
                                             tions

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

AUTHOR
     Steve Hotz hotz@isi.edu

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

BUGS
     dig has a serious case of ``creeping featurism'' -- the result of consid-
     ering several potential uses during it's 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 the resolver exits abnormally (and is not caught), the entire
     batch aborts; when such an event is trapped, dig simply continues with
     the next query.

SEE ALSO
     resolver(3),  resolv.conf(5),  named(8),  nslookup(8)

OpenBSD 2.6                     August 30, 1990                              5