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DIG(1)				     BIND9				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] [-x addr] [-y	[hmac:]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
       administrators use dig to troubleshoot DNS problems because of its
       flexibility, 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 BIND 9
       implementation 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, 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 IN and CH class names overlap with the IN and CH top	level domains
       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/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 supplied,
	   dig will perform a lookup for an A record.

OPTIONS
       The -b option sets the source IP	address	of the query to	address. This
       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>"

       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
       organized in the	same way they would be presented as queries to dig
       using the command-line interface.

       The -m option enables memory usage debugging.

       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 BIND 9. 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, type is set 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.

       The -q option sets the query name to name. This useful do distinguish
       the name	from other arguments.

       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
       transaction 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; hmac is the	type of	the TSIG, default HMAC-MD5,
       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-keygen(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
       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. The query options are:

       +[no]tcp
	   Use [do not use] TCP	when querying name servers. The	default
	   behavior is to use UDP unless an AXFR or IXFR query is requested,
	   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]showsearch
	   Perform [do not perform] a search showing intermediate results.

       +[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. 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 a OPT-OUT
	   range. AD=0 indicate	that some part of the answer was insecure or
	   not validated.

       +[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]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.

       +[no]cmd
	   Toggles the printing	of the initial comment in the output
	   identifying 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 supplied
	   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
	   behavior 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 timeout 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, the number
	   of tries is silently	rounded	up to 1.

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

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

       +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.

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

       +[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]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 behavior.

       +[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=####
	   Specifies a file containing trusted keys to be used with +sigchase.
	   Each	DNSKEY record must be on its own line.

	   If not specified, dig will look for /etc/trusted-key.key then
	   trusted-key.key in the current directory.

	   Requires dig	be compiled with -DDIG_SIGCHASE.

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

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

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
       standard	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.

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, defines the	IDN_DISABLE
       environment variable. The IDN support is	disabled if the	variable is
       set when	dig runs.

FILES
       /etc/resolv.conf

       ${HOME}/.digrc

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

BUGS
       There are probably too many query options.

COPYRIGHT
       Copyright (C) 2004-2010 Internet	Systems	Consortium, Inc. ("ISC")
       Copyright (C) 2000-2003 Internet	Software Consortium.

BIND9				 Jun 30, 2000				DIG(1)

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

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