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DIG(1)			FreeBSD	General	Commands Manual			DIG(1)

NAME
     dig -- DNS	lookup utility

SYNOPSIS
     dig [@server] [-46hiuv] [-b sourceaddr[#port]] [-c	class] [-f file]
	 [-k keyfile] [-p port]	[-q name] [-t type] [-x	addr]
	 [-y [hmac:]name:key] [name] [type] [class] [+queryopt ...]

DESCRIPTION
     The dig command is	a flexible tool	for interrogating DNS name servers.
     It	performs DNS lookups and displays the answers that are returned	from
     the name servers that were	queried.  Although dig is normally used	with
     command line arguments, it	also has a batch mode of operation for reading
     lookup requests from a file.  When	no command line	arguments or options
     are given,	dig will perform an NS query for '.' (the root).

     A typical invocation of dig looks like:

	   dig @server [options] name type [class] [+queryopt]

     @server	The name or IP address of the name server to query.  When the
		argument is a hostname,	dig resolves that name before querying
		that name server.  If no server	argument is provided, dig will
		try each of the	servers	listed in resolv.conf(5).  If no us-
		able addresses are found, dig will send	the query to the local
		host.  The reply from the name server that responds is dis-
		played.

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

     type	The type of query, as documented for -t.  The default is A.

     class	The query class, as documented for -c.	The default is IN.

     +queryopt	One or more query options, as documented in QUERY OPTIONS, be-
		low.

     The options are as	follows:

     -4	     Use IPv4 only.

     -6	     Use IPv6 only.

     -b	sourceaddr[#port]
	     Set the source IP address of the query, which is useful on	ma-
	     chines with multiple interfaces.  The sourceaddr 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	appending "#<port>".

     -c	class
	     Set the query class.  The default is IN; other classes are	HS for
	     Hesiod records and	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 com-
	     mand-line interface.

     -h	     Display a brief summary of	command	line arguments and options.

     -i	     Do	reverse	IPv6 lookups using the obsolete	RFC 1886 IP6.INT do-
	     main, which is no longer in use.  Obsolete	bit string label
	     queries (RFC 2874)	are not	attempted.

     -k	keyfile
	     Sign queries using	TSIG.  The format of the keyfile is as fol-
	     lows:

		   key "keyname" {
			   algorithm hmac;
			   secret "base64-secret";
		   };

	     keyname is	the name of the	key, and base64-secret is the
	     base64-encoded shared secret.  hmac is the	name of	the key	algo-
	     rithm; valid choices are hmac-sha1, hmac-sha224, hmac-sha256,
	     hmac-sha384, and hmac-sha512.

     -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.

     -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 de-
	     fault query type is A, unless the -x option is supplied to	indi-
	     cate a reverse lookup.  A zone transfer can be requested by spec-
	     ifying a type of AXFR.  When an incremental zone transfer is re-
	     quired, set the type to IXFR=N.  The incremental zone transfer
	     will contain the changes made to the zone since the serial	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 sup-
	     ported in BIND 9, the result will be displayed as described 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 automatically
	     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 (but see also the -i option).

     -y	[hmac:]keyname:secret
	     Sign queries using	TSIG with the given authentication key.
	     keyname 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-sha1, hmac-sha224, hmac-sha256, hmac-sha384, and
	     hmac-sha512.  If hmac is not specified, the default is
	     hmac-sha256.

	     NOTE: You should use the -k option	and avoid the -y option, be-
	     cause with	-y the shared secret is	supplied as a command line ar-
	     gument in clear text.  This may be	visible	in the output from
	     ps(1) or in a history file	maintained by the user's shell.

     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	to specify the domain name, or use "IN." and "CH." when	look-
     ing up these top level domains.

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 strategies.

     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
     +keyword=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
	     Set the "aa" flag in the query (off by default).

     +[no]additional
	     Display the additional section of a reply (on by default).

     +[no]adflag
	     Set the AD	(authentic data) bit in	the query (on by default).
	     This requests the server to return	whether	all of the answer and
	     authority 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
	     an	OPT-OUT	range.	AD=0 indicates that some part of the answer
	     was insecure or not validated.

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

     +[no]answer
	     Display the answer	section	of a reply (on by default).

     +[no]authority
	     Display the authority section of a	reply (on by default).

     +[no]besteffort
	     Attempt to	display	the contents of	messages which are malformed
	     (on by default).

     +bufsize=#
	     Set the UDP message buffer	size advertised	using EDNS0 to #
	     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 an EDNS
	     query to be sent.

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

     +[no]class
	     Display the CLASS when printing the record	(on by default).

     +[no]cmd
	     Print an initial comment identifying the version of dig and the
	     query options that	have been applied (on by default).

     +[no]comments
	     Display comment lines in the output (on by	default).

     +[no]cookie[=value]
	     Send a COOKIE EDNS	option,	containing an optional value (off by
	     default).	Replaying a COOKIE from	a previous response will allow
	     the server	to identify a previous client.

	     +cookie is	automatically set when +trace is in use, to better em-
	     ulate the default queries from a name server.

	     This option was formerly called +[no]sit (Server Identity Token).
	     In	BIND 9.10.0 through BIND 9.10.2, it sent the experimental op-
	     tion code 65001.  This was	changed	to option code 10 in BIND
	     9.10.3 when the DNS COOKIE	option was allocated.

	     The +[no]sit option is now	deprecated, but	has been retained as a
	     synonym for +[no]cookie for backward compatibility	within the
	     BIND 9.10 branch.

     +[no]crypto
	     Display cryptographic fields in DNSSEC records (on	by default).
	     The contents of these field are unnecessary to debug most DNSSEC
	     validation	failures and removing them makes it easier to see the
	     common failures.  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
	     Request DNSSEC records be sent by setting the DNSSEC OK bit (DO)
	     in	the OPT	record in the additional section of the	query (off by
	     default).

     +domain=name
	     Set the search list to contain the	single domain name, as if
	     specified in a domain directive in	resolv.conf(5),	and enable
	     search list processing as if the +search option were given	(off
	     by	default).

     +[no]edns[=#]
	     Use EDNS in the query (on by default).  A version may also	be
	     specified,	from 0 (the default) to	255.  +noedns disables EDNS
	     and clears	the remembered version.

     +ednsflags[=#]
	     Set the must-be-zero EDNS flags bits (Z bits) to the specified
	     value (0 by default).  Decimal, hex and octal encodings are ac-
	     cepted.  Setting a	named flag (e.g. DO) will silently be ignored.

     +[no]ednsnegotiation
	     Enable EDNS version negotiation (off by default).

     +[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	(off by	default).

     +[no]fail
	     Do	not try	the next server	if you receive a SERVFAIL.  This op-
	     tion is on	by default, which is the reverse of normal stub	re-
	     solver behavior.

     +[no]identify
	     Show the IP address and port number that supplied the answer (off
	     by	default).  This	option has no effect unless the	+short option
	     is	enabled.

     +[no]idnout
	     Convert puny code on output.  This	version	of dig does not	sup-
	     port IDN.

     +[no]ignore
	     Ignore truncation in UDP responses.  This option is off by	de-
	     fault, which means	truncated responses cause retrying with	TCP.

     +[no]keepopen
	     Keep the TCP socket open between queries and reuse	it.  This op-
	     tion is off by default, which means that a	new TCP	socket is cre-
	     ated for each lookup.

     +[no]multiline
	     Print records like	the SOA	records	in a verbose multi-line	format
	     with human-readable comments.  This option	is off by default,
	     which means that each record is printed on	a single line to fa-
	     cilitate machine parsing of the dig output.

     +ndots=#
	     Set the number of dots that have to appear	in name	to # for it to
	     be	considered absolute.  The default value	is that	defined	using
	     the ndots statement in resolv.conf(5), 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 resolv.conf(5) if +search is	set.

     +[no]nsid
	     Include an	EDNS name server ID request when sending a query (off
	     by	default).

     +[no]nssearch
	     Attempt to	find the authoritative name servers for	the zone con-
	     taining the name being looked up and display the SOA record that
	     each name server has for the zone (off by default).

     +[no]onesoa
	     Print only	one (starting) SOA record when performing an AXFR.
	     This option is off	by default, which means	that both the starting
	     and the ending SOA	records	are printed.

     +[no]opcode=#
	     Set or restore the	DNS message opcode to the specified value,
	     which can be QUERY	(the default), IQUERY, STATUS, NOTIFY, UPDATE,
	     or	an integer number in the range from 0 to 15.

     +[no]qr
	     Print the query as	it is sent (off	by default).

     +[no]question
	     Print the question	section	of a query as a	comment	when an	answer
	     is	returned (on by	default).

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

     +[no]recurse
	     Set the RD	(recursion desired) bit	in the query (on by default).
	     Recursion is automatically	disabled when the +nssearch or +trace
	     query options are used.

     +retry=#
	     Set the number of times to	retry UDP queries to server to #.  The
	     default is	2.  Unlike +tries, this	does not include the initial
	     query.

     +[no]rrcomments
	     Display per-record	comments in the	output (for example, human-
	     readable key information about DNSKEY records).  The default is
	     +rrcomments if +multiline mode is active or +norrcomments other-
	     wise.

     +[no]search
	     Use the search list defined by the	searchlist or domain directive
	     in	resolv.conf(5),	if any (off by default).  'ndots' from
	     resolv.conf(5) (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 (off by default).

     +[no]showsearch
	     Perform a search showing intermediate results (off	by default).

     +[no]split=#
	     Split long	hex- or	base64-formatted fields	in resource records
	     into chunks of # characters (where	# is rounded up	to the nearest
	     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
	     Print statistics: when the	query was made,	the size of the	reply
	     and so on (on by default).

     +[no]subnet=addr[/prefix]
	     Send an EDNS Client Subnet	option with the	specified IP address
	     or	network	prefix (off by default).

	     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]tcp
	     Use TCP when querying name	servers	(off by	default).  IXFR=N
	     queries use TCP unless it is explicitly disabled with +notcp.
	     AXFR queries always use TCP.

     +timeout=#
	     Set the timeout for a query to # seconds.	The default is 5 sec-
	     onds for UDP and 10 seconds for TCP.  An attempt to set # to less
	     than 1 will result	in a query timeout of 1	second being applied.

     +[no]trace
	     Trace the delegation path from the	root name servers for the name
	     being looked up (off 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 re-
	     solve 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 name server.

     +tries=#
	     Set the number of times to	try UDP	queries	to server to #.	 The
	     default is	3.  If # is less than or equal to zero,	the number of
	     tries is silently rounded up to 1.

     +[no]ttlid
	     Display the TTL when printing the record (on by default).

     +[no]vc
	     Use TCP when querying name	servers.  This alternate syntax	to
	     +[no]tcp is provided for backwards	compatibility.	The "vc"
	     stands for	"virtual circuit".

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
     tuple of name, class, type, options, flags, and query options supplied on
     the command line.	Any global query options (except the +[no]cmd option)
     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.

FILES
     /etc/resolv.conf
	     Resolver configuration file.

SEE ALSO
     host(1), resolv.conf(5)

STANDARDS
     P.	Mockapetris, Domain Names - Implementation and Specification, RFC
     1035, November 1987.

AUTHORS
     Internet Systems Consortium, Inc.

BUGS
     There are probably	too many query options.

FreeBSD	13.0			March 12, 2021			  FreeBSD 13.0

NAME | SYNOPSIS | DESCRIPTION | QUERY OPTIONS | MULTIPLE QUERIES | FILES | SEE ALSO | STANDARDS | AUTHORS | BUGS

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