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DIG(1)				    BIND 9				DIG(1)

NAME
       dig - DNS lookup	utility

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

       dig [-h]

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

DESCRIPTION
       dig  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 administrators use dig to trou-
       bleshoot	DNS problems because of	its flexibility, ease of use and clar-
       ity  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 BIND 9 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. If no usable server addresses
       are found, dig will send	the query to the local host.

       When no command line arguments or options are given, dig	 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.	 The -r	option disables	this feature, for scripts that
       need predictable	behaviour.

       The IN and CH class names overlap with the IN and CH top	 level	domain
       names.  Either use the -t and -c	options	to specify the type and	class,
       use the -q the specify the domain name, or use  "IN."  and  "CH."  when
       looking up these	top level domains.

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/re-
	      solv.conf; if an address is found	there,	it  queries  the  name
	      server at	that address. If either	of the -4 or -6	options	are in
	      use, then	only addresses for the corresponding transport will be
	      tried. If	no usable addresses are	found, dig will	send the query
	      to the local host. 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	MDASH ANY, A, MX, SIG,
	      etc.  type can be	any valid query	type. If no type  argument  is
	      supplied,	dig will perform a lookup for an A record.

OPTIONS
       -4     Use IPv4 only.

       -6     Use IPv6 only.

       -b address[#port]
	      Set  the	source	IP address of the query. The address must be a
	      valid address on	one  of	 the  host's  network  interfaces,  or
	      "0.0.0.0"	 or "::". An optional port may be specified by append-
	      ing "#<port>"

       -c class
	      Set the query class. The default class is	IN; other classes  are
	      HS for Hesiod records or CH for Chaosnet records.

       -f file
	      Batch  mode: dig reads a list of lookup requests to process from
	      the given	file. Each line	in the file should be organized	in the
	      same  way	 they  would  be presented as queries to dig using the
	      command-line interface.

       -k keyfile
	      Sign queries using TSIG using a key read from  the  given	 file.
	      Key  files  can be generated using tsig-keygen8. 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.

       -m     Enable memory usage debugging.

       -p port
	      Send  the	query to a non-standard	port on	the server, instead of
	      the default port 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.

       -q name
	      The domain name to query.	This is	useful to distinguish the name
	      from other arguments.

       -r     Do  not  read  options  from  ${HOME}/.digrc. This is useful for
	      scripts that need	predictable behaviour.

       -t type
	      The resource record type to query. It can	 be  any  valid	 query
	      type.  If	 it  is	a resource record type supported in BIND 9, it
	      can be given by the type mnemonic	(such as "NS" or "AAAA").  The
	      default  query  type is "A", unless the -x option	is supplied to
	      indicate a reverse lookup. A zone	transfer can be	 requested  by
	      specifying  a  type  of  AXFR. When an incremental zone transfer
	      (IXFR) is	required, set the type to ixfr=N. The incremental zone
	      transfer will contain the	changes	made to	the zone since the se-
	      rial number in the zone's	SOA record was N.

	      All resource record types	can be expressed  as  "TYPEnn",	 where
	      "nn"  is	the number of the type.	If the resource	record type is
	      not supported in BIND 9, the result will	be  displayed  as  de-
	      scribed in RFC 3597.

       -u     Print query times	in microseconds	instead	of milliseconds.

       -v     Print the	version	number and exit.

       -x addr
	      Simplified  reverse lookups, for mapping addresses to names. The
	      addr is  an  IPv4	 address  in  dotted-decimal  notation,	 or  a
	      colon-delimited  IPv6  address. When the -x is used, there is no
	      need to provide the name,	class and type arguments.   dig	 auto-
	      matically	   performs    a    lookup    for    a	  name	  like
	      94.2.0.192.in-addr.arpa and sets the query type and class	to PTR
	      and  IN  respectively. IPv6 addresses are	looked up using	nibble
	      format under the IP6.ARPA	domain.

       -y [hmac:]keyname:secret
	      Sign queries using TSIG with the given authentication key.  key-
	      name  is	the  name of the key, and secret is the	base64 encoded
	      shared secret. hmac is the name  of  the	key  algorithm;	 valid
	      choices	are  hmac-md5,	hmac-sha1,  hmac-sha224,  hmac-sha256,
	      hmac-sha384, or hmac-sha512. If hmac is not specified,  the  de-
	      fault is hmac-md5	or if MD5 was disabled hmac-sha256.

       NOTE:
	  You  should  use the -k option and avoid the -y option, because with
	  -y the shared	secret is supplied as a	command	line argument in clear
	  text.	 This  may  be	visible	in the output from ps1 or in a history
	  file maintained by the user's	shell.

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 an-
       swer  get  printed,  and	others determine the timeout and retry strate-
       gies.

       Each query option is identified by a keyword preceded by	 a  plus  sign
       (+). Some keywords set or reset an option. These	may be preceded	by the
       string no to negate the meaning of that keyword.	Other keywords	assign
       values  to  options like	the timeout interval. They have	the form +key-
       word=value. Keywords may	be abbreviated,	provided the  abbreviation  is
       unambiguous;  for  example, +cd is equivalent to	+cdflag. The query op-
       tions are:

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

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

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

       +[no]adflag
	      Set  [do not set]	the AD (authentic data)	bit in the query. This
	      requests the server to return whether all	of the answer and  au-
	      thority  sections	have all been validated	as secure according to
	      the security policy of  the  server.  AD=1  indicates  that  all
	      records have been	validated as secure and	the answer is not from
	      a	OPT-OUT	range. AD=0 indicate that some part of the answer  was
	      insecure or not validated.  This bit is set by default.

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

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

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

       +[no]badcookie
	      Retry  lookup with the new server	cookie if a BADCOOKIE response
	      is received.

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

       +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. Values other than zero  will	cause  a  EDNS
	      query to be sent.

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

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

       +[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 option always has global effect; it cannot	be set
	      globally and then	overridden on a	per-lookup basis.  The default
	      is to print this comment.

       +[no]comments
	      Toggles  the  display  of	some comment lines in the output, con-
	      taining information about	the packet header and  OPT  pseudosec-
	      tion,  and the names of the response section.  The default is to
	      print these comments.

	      Other types of comments in the output are	not affected  by  this
	      option, but can be controlled using other	command	line switches.
	      These   include	+[no]cmd,   +[no]question,   +[no]stats,   and
	      +[no]rrcomments.

       +[no]cookie=####
	      Send  a  COOKIE  EDNS  option,  with optional value. Replaying a
	      COOKIE from a previous response will allow the server  to	 iden-
	      tify a previous client. The default is +cookie.

	      +cookie is also set when +trace is set to	better emulate the de-
	      fault queries from a nameserver.

       +[no]crypto
	      Toggle the display of cryptographic fields  in  DNSSEC  records.
	      The contents of these field are unnecessary to debug most	DNSSEC
	      validation failures and removing them makes it easier to see the
	      common  failures.	 The  default  is  to display the fields. When
	      omitted they are replaced	by the string "[omitted]"  or  in  the
	      DNSKEY  case the key id is displayed as the replacement, e.g. "[
	      key id = value ]".

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

       +[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.

       +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.

       +dscp=value
	      Set the DSCP code	point to be used when sending the query. Valid
	      DSCP code	points are in the range	[0..63]. By  default  no  code
	      point is explicitly set.

       +[no]edns[=#]
	      Specify  the  EDNS  version to query with. Valid values are 0 to
	      255.  Setting the	EDNS version will cause	a  EDNS	 query	to  be
	      sent.   +noedns  clears the remembered EDNS version. EDNS	is set
	      to 0 by default.

       +[no]ednsflags[=#]
	      Set the must-be-zero EDNS	flags bits (Z bits) to	the  specified
	      value.  Decimal, hex and octal encodings are accepted. Setting a
	      named flag (e.g. DO) will	silently be ignored. By	default, no  Z
	      bits are set.

       +[no]ednsnegotiation
	      Enable  /	disable	EDNS version negotiation. By default EDNS ver-
	      sion negotiation is enabled.

       +[no]ednsopt[=code[:value]]
	      Specify EDNS option with code point code and optionally  payload
	      of value as a hexadecimal	string.	code can be either an EDNS op-
	      tion name	(for example, NSID or ECS), or	an  arbitrary  numeric
	      value. +noednsopt	clears the EDNS	options	to be sent.

       +[no]expire
	      Send an EDNS Expire option.

       +[no]fail
	      Do  not  try  the	next server if you receive a SERVFAIL. The de-
	      fault is to not try the next server which	is the reverse of nor-
	      mal stub resolver	behavior.

       +[no]header-only
	      Send  a  query with a DNS	header without a question section. The
	      default is to add	a question section. The	query type  and	 query
	      name are ignored when this is set.

       +[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]idnin
	      Process  [do  not	 process]  IDN domain names on input. This re-
	      quires IDN SUPPORT to have been enabled at compile time.

	      The default is to	process	IDN input when standard	 output	 is  a
	      tty.  The	IDN processing on input	is disabled when dig output is
	      redirected to files, pipes, and other non-tty file descriptors.

       +[no]idnout
	      Convert [do not convert] puny code on output. This requires  IDN
	      SUPPORT to have been enabled at compile time.

	      The default is to	process	puny code on output when standard out-
	      put is a tty. The	puny code processing  on  output  is  disabled
	      when dig output is redirected to files, pipes, and other non-tty
	      file descriptors.

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

       +[no]keepalive
	      Send [or do not send] an EDNS Keepalive option.

       +[no]keepopen
	      Keep  the	 TCP  socket  open between queries and reuse it	rather
	      than creating a new TCP socket for each lookup. The  default  is
	      +nokeepopen.

       +[no]mapped
	      Allow mapped IPv4	over IPv6 addresses to be used.	The default is
	      +mapped.

       +[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.

       +ndots=D
	      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 us-
	      ing  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 if +search is
	      set.

       +[no]nsid
	      Include an EDNS name server ID request when sending a query.

       +[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.  Addresses of servers that that did	not respond  are  also
	      printed.

       +[no]onesoa
	      Print  only  one	(starting) SOA record when performing an AXFR.
	      The default is  to  print	 both  the  starting  and  ending  SOA
	      records.

       +[no]opcode=value
	      Set [restore] the	DNS message opcode to the specified value. The
	      default value is QUERY (0).

       +padding=value
	      Pad the size of the query	packet using the EDNS  Padding	option
	      to blocks	of value bytes.	For example, +padding=32 would cause a
	      48-byte query to be padded to 64 bytes. The default  block  size
	      is 0, which disables padding. The	maximum	is 512.	Values are or-
	      dinarily expected	to be powers of	two,  such  as	128;  however,
	      this  is	not mandatory. Responses to padded queries may also be
	      padded, but only if the query uses TCP or	DNS COOKIE.

       +[no]qr
	      Toggles the display of the query message as it is	sent.  By  de-
	      fault, the query is not printed.

       +[no]question
	      Toggles  the  display of the question section of a query when an
	      answer is	returned.  The default is to print the	question  sec-
	      tion as a	comment.

       +[no]raflag
	      Set  [do not set]	the RA (Recursion Available) bit in the	query.
	      The default is +noraflag.	This bit  should  be  ignored  by  the
	      server for QUERY.

       +[no]rdflag
	      A	synonym	for +[no]recurse.

       +[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.

       +retry=T
	      Sets the number of times to retry	UDP queries to server to T in-
	      stead  of	 the  default, 2. Unlike +tries, this does not include
	      the initial query.

       +[no]rrcomments
	      Toggle the display of per-record comments	in the output (for ex-
	      ample, human-readable key	information about DNSKEY records). The
	      default is not to	print record comments unless multiline mode is
	      active.

       +[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.

	      'ndots'  from resolv.conf	(default 1) which may be overridden by
	      +ndots determines	if the name will be treated as relative	or not
	      and hence	whether	a search is eventually performed or not.

       +[no]short
	      Provide a	terse answer.  The default is to print the answer in a
	      verbose form.  This option always	has global effect;  it	cannot
	      be set globally and then overridden on a per-lookup basis.

       +[no]showsearch
	      Perform [do not perform] a search	showing	intermediate results.

       +[no]sigchase
	      This  feature is now obsolete and	has been removed; use delv in-
	      stead.

       +split=W
	      Split long hex- or base64-formatted fields in  resource  records
	      into  chunks of W	characters (where W is rounded up to the near-
	      est multiple of 4). +nosplit or +split=0 causes fields not to be
	      split  at	 all.  The  default is 56 characters, or 44 characters
	      when multiline mode is active.

       +[no]stats
	      Toggles the printing of statistics: when the query was made, the
	      size  of	the reply and so on.  The default behavior is to print
	      the query	statistics as a	comment	after each lookup.

       +[no]subnet=addr[/prefix-length]
	      Send (don't send)	an EDNS	Client Subnet option with  the	speci-
	      fied IP address or network prefix.

	      dig  +subnet=0.0.0.0/0, or simply	dig +subnet=0 for short, sends
	      an EDNS CLIENT-SUBNET option with	an empty address and a	source
	      prefix-length  of	 zero,	which  signals	a  resolver  that  the
	      client's address information must	not  be	 used  when  resolving
	      this query.

       +[no]tcflag
	      Set  [do	not set] the TC	(TrunCation) bit in the	query. The de-
	      fault is +notcflag. This bit should be ignored by	the server for
	      QUERY.

       +[no]tcp
	      Use [do not use] TCP when	querying name servers. The default be-
	      havior is	to use UDP unless a type any or	ixfr=N	query  is  re-
	      quested,	in  which case the default is TCP. AXFR	queries	always
	      use TCP.

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

       +[no]topdown
	      This feature is related to dig +sigchase,	which is obsolete  and
	      has been removed.	Use delv instead.

       +[no]trace
	      Toggle tracing of	the delegation path from the root name servers
	      for the name being looked	up. Tracing is	disabled  by  default.
	      When  tracing is enabled,	dig makes iterative queries to resolve
	      the name being looked up.	It will	follow referrals from the root
	      servers,	showing	 the  answer from each server that was used to
	      resolve the lookup.

	      If @server is also specified, it affects only the	initial	 query
	      for the root zone	name servers.

	      +dnssec is also set when +trace is set to	better emulate the de-
	      fault queries from a nameserver.

       +tries=T
	      Sets the number of times to try UDP queries to server to	T  in-
	      stead of the default, 3. If T is less than or equal to zero, the
	      number of	tries is silently rounded up to	1.

       +trusted-key=####
	      Formerly specified trusted keys for use with dig +sigchase. This
	      feature is now obsolete and has been removed; use	delv instead.

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

       +[no]ttlunits
	      Display [do not display] the TTL in friendly human-readable time
	      units of "s", "m", "h", "d", and "w", representing seconds, min-
	      utes, hours, days	and weeks. Implies +ttlid.

       +[no]unexpected
	      Accept  [do not accept] answers from unexpected sources.	By de-
	      fault, dig won't accept a	reply from a source other than the one
	      to which it sent the query.

       +[no]unknownformat
	      Print  all  RDATA	 in  unknown  RR type presentation format (RFC
	      3597).  The default is to	print RDATA for	 known	types  in  the
	      type's presentation format.

       +[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]yaml
	      Print  the  responses  (and,  if <option>+qr</option> is in use,
	      also the outgoing	queries) in a detailed YAML format.

       +[no]zflag
	      Set [do not set] the last	unassigned DNS header flag  in	a  DNS
	      query.  This flag	is off by default.

MULTIPLE QUERIES
       The  BIND  9 implementation of dig supports specifying multiple queries
       on the command line (in addition	to supporting the -f  batch  file  op-
       tion). 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
       tuple of	name, class, type, options, flags, and query options  supplied
       on  the	command	 line.	Any  global query options (except +[no]cmd and
       +[no]short options) can be overridden by	a query-specific set of	 query
       options.	For example:

	  dig +qr www.isc.org any -x 127.0.0.1 isc.org ns +noqr

       shows  how  dig	could  be  used	 from  the  command line to make three
       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.

IDN SUPPORT
       If dig has been built with IDN (internationalized domain	name) support,
       it can accept and display non-ASCII  domain  names.  dig	 appropriately
       converts	 character encoding of domain name before sending a request to
       DNS server or displaying	a reply	from the server. If you'd like to turn
       off the IDN support for some reason, use	parameters +noidnin and	+noid-
       nout or define the IDN_DISABLE environment variable.

FILES
       /etc/resolv.conf

       ${HOME}/.digrc

SEE ALSO
       delv(1),	host(1), named(8), dnssec-keygen(8), RFC 1035.

BUGS
       There are probably too many query options.

AUTHOR
       Internet	Systems	Consortium

COPYRIGHT
       2020, Internet Systems Consortium

9.16.6				  2020-08-10				DIG(1)

NAME | SYNOPSIS | DESCRIPTION | SIMPLE USAGE | OPTIONS | QUERY OPTIONS | MULTIPLE QUERIES | IDN SUPPORT | FILES | SEE ALSO | BUGS | AUTHOR | COPYRIGHT

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