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dig(1)

NAME

       dig - DNS lookup utility

SYNOPSIS

       dig  [  @server	]  [ -b address ]  [ -c class ]  [ -f filename ]  [ -k
       filename ]  [ -p port# ]  [ -t type ]  [ -x addr ]  [ -y name:key ]   [
       -4 ]  [ -6 ]  [ name ]  [ type ]  [ class ]  [ queryopt... ]

       dig [ -h ]

       dig [ global-queryopt... ]  [ query... ]

DESCRIPTION

       dig  (domain  information  groper) is a flexible tool for interrogating
       DNS name servers. It performs DNS lookups and displays the answers that
       are returned from the name server(s) that were queried. Most DNS admin-
       istrators use dig to troubleshoot DNS problems because of its flexibil-
       ity, ease of use and clarity of output. Other lookup tools tend to have
       less functionality than dig.

       Although dig is normally used with command-line arguments, it also  has
       a  batch  mode  of operation for reading lookup requests from a file. A
       brief summary of its command-line arguments and options is printed when
       the -h option is given.	Unlike earlier versions, the BIND9 implementa-
       tion of dig allows multiple lookups to be issued from the command line.

       Unless it is told to query a specific name server, dig will try each of
       the servers listed in /etc/resolv.conf.

       When no command line arguments or options are given, will perform an NS
       query for "." (the root).

       It  is  possible  to  set per-user defaults for dig via ${HOME}/.digrc.
       This file is read and any options in it are applied before the  command
       line arguments.

SIMPLE USAGE

       A typical invocation of dig looks like:

	dig @server name type

       where:

       server is  the name or IP address of the name server to query. This can
	      be an IPv4 address in dotted-decimal notation or an IPv6 address
	      in  colon-delimited  notation. When the supplied server argument
	      is a hostname, dig resolves that name before querying that  name
	      server.	If  no	server	argument  is  provided,  dig  consults
	      /etc/resolv.conf and queries the name servers listed there.  The
	      reply from the name server that responds is displayed.

       name   is the name of the resource record that is to be looked up.

       type   indicates  what  type  of  query is required -- ANY, A, MX, SIG,
	      etc.  type can be any valid query type. If no type  argument  is
       The default query class (IN for	internet)  is  overridden  by  the  -c
       option.	class  is any valid class, such as HS for Hesiod records or CH
       for CHAOSNET records.

       The -f option makes dig	operate in batch mode by  reading  a  list  of
       lookup  requests to process from the file filename. The file contains a
       number of queries, one per line. Each  entry  in  the  file  should  be
       organised  in  the  same  way they would be presented as queries to dig
       using the command-line interface.

       If a non-standard port number is to be queried, the -p option is  used.
       port#  is the port number that dig will send its queries instead of the
       standard DNS port number 53. This option would be used to test  a  name
       server that has been configured to listen for queries on a non-standard
       port number.

       The -4 option forces dig to only  use  IPv4  query  transport.  The  -6
       option forces dig to only use IPv6 query transport.

       The  -t	option	sets the query type to type. It can be any valid query
       type which is supported in BIND9. The default query  type  "A",	unless
       the  -x option is supplied to indicate a reverse lookup.  A zone trans-
       fer can be requested by specifying a type of AXFR. When an  incremental
       zone transfer (IXFR) is required, type is set to ixfr=N.  The incremen-
       tal zone transfer will contain the changes made to the zone  since  the
       serial number in the zone's SOA record was N.

       Reverse lookups - mapping addresses to names - are simplified by the -x
       option. addr is an IPv4 address in dotted-decimal notation, or a colon-
       delimited  IPv6 address.  When this option is used, there is no need to
       provide the name, class and type arguments. dig automatically  performs
       a  lookup  for  a name like 11.12.13.10.in-addr.arpa and sets the query
       type and class to PTR and IN respectively. By default,  IPv6  addresses
       are  looked  up	using nibble format under the IP6.ARPA domain.	To use
       the older RFC1886 method  using	the  IP6.INT  domain  specify  the  -i
       option.	Bit  string  labels (RFC2874) are now experimental and are not
       attempted.

       To sign the DNS queries sent by dig and their responses using  transac-
       tion  signatures  (TSIG),  specify a TSIG key file using the -k option.
       You can also specify the TSIG key itself on the command line using  the
       -y  option; name is the name of the TSIG key and key is the actual key.
       The key is a base-64 encoded string, typically generated by dnssec-key-
       gen(8).	Caution should be taken when using the -y option on multi-user
       systems as the key can be visible in the output from ps(1)  or  in  the
       shell's history file. When using TSIG authentication with dig, the name
       server that is queried needs to know the  key  and  algorithm  that  is
       being  used.  In  BIND,	this  is done by providing appropriate key and
       server statements in named.conf.

QUERY OPTIONS

       dig provides a number of query options which affect the	way  in  which
       lookups	are made and the results displayed. Some of these set or reset
       flag bits in the query header, some determine  which  sections  of  the
       answer  get printed, and others determine the timeout and retry strate-
       gies.

       Each query option is identified by a keyword preceded by  a  plus  sign
	      in which case a TCP connection is used.

       +[no]vc
	      Use [do not use] TCP when querying name servers. This  alternate
	      syntax  to +[no]tcp is provided for backwards compatibility. The
	      "vc" stands for "virtual circuit".

       +[no]ignore
	      Ignore truncation in UDP responses instead of retrying with TCP.
	      By default, TCP retries are performed.

       +domain=somename
	      Set the search list to contain the single domain somename, as if
	      specified in a domain directive in /etc/resolv.conf, and	enable
	      search list processing as if the +search option were given.

       +[no]search
	      Use  [do	not  use] the search list defined by the searchlist or
	      domain directive in resolv.conf (if any).  The  search  list  is
	      not used by default.

       +[no]defname
	      Deprecated, treated as a synonym for +[no]search

       +[no]aaonly
	      Sets the "aa" flag in the query.

       +[no]aaflag
	      A synonym for +[no]aaonly.

       +[no]adflag
	      Set  [do	not set] the AD (authentic data) bit in the query. The
	      AD bit currently has a standard meaning only in  responses,  not
	      in  queries, but the ability to set the bit in the query is pro-
	      vided for completeness.

       +[no]cdflag
	      Set [do not set] the CD (checking disabled) bit  in  the	query.
	      This  requests  the  server  to not perform DNSSEC validation of
	      responses.

       +[no]cl
	      Display [do not display] the CLASS when printing the record.

       +[no]ttlid
	      Display [do not display] the TTL when printing the record.

       +[no]recurse
	      Toggle the setting of the RD  (recursion	desired)  bit  in  the
	      query.   This  bit  is  set by default, which means dig normally
	      sends recursive queries.	Recursion  is  automatically  disabled
	      when the +nssearch or +trace query options are used.

       +[no]nssearch
	      When  this option is set, dig attempts to find the authoritative
	      name servers for the zone containing the name  being  looked  up
	      and  display  the  SOA  record that each name server has for the
	      zone.

       +[no]cmd
	      toggles  the printing of the initial comment in the output iden-
	      tifying the version of dig and the query options that have  been
	      applied. This comment is printed by default.

       +[no]short
	      Provide  a terse answer. The default is to print the answer in a
	      verbose form.

       +[no]identify
	      Show [or do not show] the IP address and port number  that  sup-
	      plied  the  answer  when	the +short option is enabled. If short
	      form answers are requested, the  default	is  not  to  show  the
	      source  address  and port number of the server that provided the
	      answer.

       +[no]comments
	      Toggle the display of comment lines in the output.  The  default
	      is to print comments.

       +[no]stats
	      This  query  option toggles the printing of statistics: when the
	      query was made, the size of the reply and so on. The default be-
	      haviour is to print the query statistics.

       +[no]qr
	      Print  [do  not print] the query as it is sent.  By default, the
	      query is not printed.

       +[no]question
	      Print [do not print] the question section of  a  query  when  an
	      answer is returned. The default is to print the question section
	      as a comment.

       +[no]answer
	      Display [do not display] the answer  section  of	a  reply.  The
	      default is to display it.

       +[no]authority
	      Display  [do  not display] the authority section of a reply. The
	      default is to display it.

       +[no]additional
	      Display [do not display] the additional section of a reply.  The
	      default is to display it.

       +[no]all
	      Set or clear all display flags.

       +time=T
	      Sets  the timeout for a query to T seconds. The default time out
	      is 5 seconds.  An attempt to set T to less than 1 will result in
	      a query timeout of 1 second being applied.

       +tries=T
	      Sets  the  number  of  times  to	try UDP queries to server to T
	      instead of the default, 3. If T is less than or equal  to  zero,
	      Set  the	number of dots that have to appear in name to D for it
	      to be considered absolute. The default  value  is  that  defined
	      using  the ndots statement in /etc/resolv.conf, or 1 if no ndots
	      statement is present. Names with fewer dots are  interpreted  as
	      relative names and will be searched for in the domains listed in
	      the search or domain directive in /etc/resolv.conf.

       +bufsize=B
	      Set the UDP message buffer size  advertised  using  EDNS0  to  B
	      bytes.  The  maximum  and minimum sizes of this buffer are 65535
	      and 0 respectively. Values outside this range are rounded up  or
	      down appropriately.

       +[no]multiline
	      Print  records like the SOA records in a verbose multi-line for-
	      mat with human-readable comments. The default is to  print  each
	      record  on  a  single line, to facilitate machine parsing of the
	      dig output.

       +[no]fail
	      Do not try the next  server  if  you  receive  a	SERVFAIL.  The
	      default  is  to  not try the next server which is the reverse of
	      normal stub resolver behaviour.

       +[no]besteffort
	      Attempt to display the contents of messages which are malformed.
	      The default is to not display malformed answers.

       +[no]dnssec
	      Requests	DNSSEC	records  be  sent by setting the DNSSEC OK bit
	      (DO) in the OPT record in the additional section of the query.

       +[no]sigchase
	      Chase DNSSEC signature chains. Requires  dig  be	compiled  with
	      -DDIG_SIGCHASE.

       +trusted-key=####
	      Specify  a  trusted key to be used with +sigchase.  Requires dig
	      be compiled with -DDIG_SIGCHASE.

       +[no]topdown
	      When chasing DNSSEC signature chains perform a top down  valida-
	      tion.  Requires dig be compiled with -DDIG_SIGCHASE.

MULTIPLE QUERIES

       The  BIND 9 implementation of dig  supports specifying multiple queries
       on the command line (in	addition  to  supporting  the  -f  batch  file
       option).  Each  of  those  queries  can be supplied with its own set of
       flags, options and query options.

       In this case, each query argument represent an individual query in  the
       command-line  syntax described above. Each consists of any of the stan-
       dard options and flags, the name to be looked  up,  an  optional  query
       type  and  class  and  any query options that should be applied to that
       query.

       A global set of query options, which should be applied to all  queries,
       can also be supplied. These global query options must precede the first
       lookups: an ANY query for www.isc.org, a reverse  lookup  of  127.0.0.1
       and  a  query  for the NS records of isc.org.  A global query option of
       +qr is applied, so that dig shows the initial query it  made  for  each
       lookup.	The  final query has a local query option of +noqr which means
       that dig will not print the initial query  when	it  looks  up  the  NS
       records for isc.org.

FILES

       /etc/resolv.conf

       ${HOME}/.digrc

SEE ALSO

       host(1), named(8), dnssec-keygen(8), RFC1035.

BUGS

       There are probably too many query options.

BIND9				 Jun 30, 2000				DIG(1)

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