dig(1M) 																   dig(1M)

NAME

       dig - domain information groper

SYNOPSIS

   Single Query
       class] filename] filename] port] type] addr] [name] [type] [class] [queryopt]...

   Help

   Multiple Query
       [global-queryopt]... [query]...

DESCRIPTION

       the domain information groper, is a flexible tool for interrogating Domain Name System (DNS) servers.  It performs DNS lookups and displays
       the answers that are returned from the name servers that were queried.  Most DNS administrators use to troubleshoot DNS problems because of
       its  flexibility, ease of use, and clarity of output.  The command has two modes: a simple command-line mode for single or multiple queries
       and a batch mode for reading lookup requests from a file option).

       Unless it is told to query a specific name server option), tries each of the servers listed in

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

       A simple, typical invocation of looks like:

   Options
       Options can be specified in any order.

       Use	 server as the name server to query.  server can be a host name, an IPv4 address in dotted-decimal notation, or an IPv6 address in
		 colon-delimited  notation.   When  server  is	a  host name, resolves that name before querying that name server.  If is omitted,
		 queries the name servers listed in The reply from the name server that responds is displayed.

       Use the IPv4 query transport only.

       Use the IPv6 query transport only.

       Set the source IP address of the query to
		 address.  This must be a valid address on one of the host's network interfaces or or An optional port on the source may be speci-
		 fied by appending

       Set the query class.
		 The default is for Internet.  class can also be for Hesiod records, or for Chaosnet records.

       Make	 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 it would be presented as a query to using  the
		 command-line interface.

       Display the annotated syntax for the command.
		 If other options or operands are specified, they are ignored.

       Look up IPv6 addresses using the older IP6.INT domain,
		 described in RFC 1886.  See the option.

       Specify a TSIG key file in order to sign the DNS queries sent by
		 and their responses using transaction signatures (TSIG).

       Send queries to a port number,
		 port,	instead  of  to the standard DNS port number 53.  Use this option to test a name server that has been configured to listen
		 for queries on a nonstandard port number.

       Set the query type to
		 type.	It can be any valid query type which is supported in BIND 9.  For potential values, see the command in nslookup(1) and the
		 discussion in named.conf(4).

		 The default query type is unless the option is supplied to indicate a reverse lookup.	A zone transfer can be requested by speci-
		 fying a type of When an incremental zone transfer is required, set type to The incremental zone transfer will contain the changes
		 made to the zone since the serial number in the zone's record was

       Simplify reverse lookups (mapping addresses to names).
		 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, or type operands.	automatically performs a lookup for a name like and sets the query type and  class
		 to  and  respectively.  By default, IPv6 addresses are looked up using nibble format under the IP6.ARPA domain.  To use the older
		 RFC 1886 method (IP6.INT) domain, also specify the option.

       Specify the TSIG key itself on the command line.
		 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  (see
		 dnssec-keygen(1)).  Be cautious when using the option on multiuser systems as the key can be visible in the output from or in the
		 shell's history file.	When using TSIG authentication with 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

   Operands
       Operands are order-dependent.

       class	 Set the query class.  See the option.	The class operand overrides any preceding option.

       global-queryopt
		 Query options (see the queryopt operand) at the beginning of the command are "global".  They affect all subsequent queries on the
		 command line (see the query operand).

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

       query	 A set of command-line options, operands, and query options that form a single lookup query, as shown in the  syntax  in  (without
		 the command word).

       queryopt  Query options at the end of a query modify the lookup for that query only.  They override any global query options.  See the sub-
		 section for details.

       type	 Set the query type.  See the option.  The type operand overrides any preceding option.

   Query Options
       uses a number of query options to modify lookups and the results that are displayed.  Some options set or clear	flag  bits  in	the  query
       header,	some  options  determine which sections of the answer get displayed, and other options determine the timeout and retry strategies.
       There are two formats:

	      The prefix	  causes an option to be reset, negated, or cleared.  The action is described in brackets ([...]).

	      The keyword assigns a value to an option.
       The query options are:

       A synonym for
		 The default is

       Set [do not set] the AA (authoritative answer) flag in the query.
		 The default is

       Display [do not display] the additional section of a reply.
		 The default is

       Set [do not set] the AD (authenticate data) bit in the query.
		 The AD bit currently has a standard meaning only in responses and not in queries.  The ability to set the bit	in  the  query	is
		 provided for completeness.  The default is

       Set [clear] all display flags.
		 The default is

       Display [do not display] the answer section of a reply.
		 The default is

       Display [do not display] the authority section of a reply.
		 The default is

       Attempt [do not attempt] to display the contents of messages that are malformed.
		 The default is

       Set the UDP message buffer size advertised using Extended DNS ( EDNS) to
		 B bytes.  The maximum and minimum sizes of this buffer are 65535 and 0, respectively.	If the B size is specified outside of this
		 range, then the size is adjusted appropriately.  The default is 2048.

       Set [do not set] the CD (checking disabled) bit in the query,
		 which requests the server not to perform DNSSEC validation of responses.  The default is

       Display [do not display] the CLASS when printing the record.
		 The default is

       Display [do not display] an initial comment in the output
		 identifying the version of and the command-line arguments that were specified.  The default is

       Display [do not display] comment lines in the output.
		 The default is

       Deprecated; treated as a synonym for
		 The default is

       Request DNSSEC records be sent by setting the DNSSEC OK bit (DO)
		 in the OPT record in the additional section of the query.  The default is

       Set the default domain to
		 somename as if specified in a directive in the file, and enable search list processing as if the option were given.  If  this	is
		 not used, the query has to contain a fully qualified domain name (FQDN) for forward lookup.

       Do not try [try] the next server if you receive a SERVFAIL.
		 The default is which is the reverse of normal stub resolver behavior.

       Show [do not show]
		 the IP address and port number that supplied the answer when short form answers are requested with the query option.  The default
		 is

       Ignore [do not ignore] truncation in UDP responses instead
		 of retrying with TCP.	The default is (perform TCP retries).

       Print [do not print] records like the
		 records in a verbose multiline format with human-readable comments.  The default is print each record on a single  line,  thereby
		 facilitating machine parsing of the output.

       Set the number of dots (periods) that appear in
		 hostname  to D.  The default for D is the value given in the statement in or if there is no statement.  Names with fewer dots are
		 interpreted as relative names and will be searched for in the domains listed in the search or the domain directive in the file.

       Attempt [do not attempt] to find the authoritative
		 name servers for the zone containing the name being looked up and display the record that each name  server  has  for	the  zone.
		 also sets the query option.  The default is

       Print [do not print] the query before actually sending the query.
		 The default is

       Print [do not print] the question section of a query when an
		 answer is returned.  The default is print the question section as a comment.

       Set [do not set] the RD (recursion desired) bit in the query,
		 to have send recursive queries.  The default is except that recursion is automatically disabled when the or query option is used.

       Set the number of times to retry UDP queries to server to
		 A.  Unlike this count does not include the initial query.  The default is 2.

       Use [do not use] the search list in
		 (if any).  The default is

       Display [do not display] a short answer.
		 The  query  results  can be displayed in two forms: Complete and Short answers.  In the short form, only the result is displayed.
		 In the complete form, additional information (for example, about other servers that might answer your query)  is  also  included.
		 The default is

       Print [do not print] statistics such as the size of the reply
		 when the query was made.  The default is

       Use [do not use] TCP when querying name servers.
		 The default is use TCP if an or query is requested, and use UDP otherwise.

       Set the timeout for a query to
		 T seconds.  The minimum value of T is	1 second.  If T is less than 1, it is set to 1 second.	The default timeout is 5 seconds.

       Trace [do not trace] the delegation path from the root name
		 servers  for the name being looked up.  When tracing is enabled, makes iterative queries to resolve the name that is being looked
		 up.  It will follow referrals from the root servers, showing the answer from each server that was used  to  resolve  the  lookup.
		 also sets the query option.  The default is

       Set the number of times to retry UDP queries to server to
		 A.  If A is less than 1, it is set to 1.  The default is 3.

       Display [do not display] the TTL when printing the record.
		 The default is

       Use [do not use] virtual circuit when querying name servers.
		 This alternate syntax to is provided for backward compatibility.  The default is

   Multiple Queries
       The  BIND 9 implementation of allows multiple queries on the command line (in addition to supporting the batch file option).  Each of those
       queries can be supplied with its own set of options, query type, query class, and query options.  See in

   Global Query Options
       A global set of query options, which is applied to all queries, can precede the first set of options, name, query type,	query  class,  and
       query  options  supplied on the command line.  Any global query options (except the query option) can be overridden by a query-specific set
       of query options.  See in

EXAMPLES

   Example 1
       To look up information about domain using DNS-Server asking for host address records:

   Example 2
       To query using DNS-Server without authentication, asking for records:

   Example 3
       To request a transfer:

   Example 4
       To request a transfer with Transaction Signature (TSIG):

       The key is

       To secure server-to-server communication, BIND 9 primarily uses TSIG for zone transfer, notify, and recursive query messages.  TSIG is very
       useful for dynamic updates.

   Example 5
       To make three lookups from the command line:

       The three queries are:

	      An		       query for domain name

	      A reverse lookup of 127.0.0.1

	      A name server lookup for domain
				       suppressing the query display for this query only

AUTHOR

       was developed by the Internet Systems Consortium (ISC).

SEE ALSO

       dnssec-keygen(1), dnssec-signzone(1), host(1), nsupdate(1), hosts_to_named(1M), named(1M), gethostent(3N), hostname(5).

       Requests for Comments (RFC): 1886, available online at

       available online at

       available from the Internet Systems Consortium at

								     BIND 9.3								   dig(1M)