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27 .TH "DIG" "1" "2014\-02\-12" "ISC" "BIND9"
28 .\" -----------------------------------------------------------------
29 .\" * Define some portability stuff
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31 .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
32 .\" http://bugs.debian.org/507673
33 .\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
34 .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
37 .\" -----------------------------------------------------------------
38 .\" * set default formatting
39 .\" -----------------------------------------------------------------
40 .\" disable hyphenation
42 .\" disable justification (adjust text to left margin only)
44 .\" -----------------------------------------------------------------
45 .\" * MAIN CONTENT STARTS HERE *
46 .\" -----------------------------------------------------------------
48 dig \- DNS lookup utility
51 \fBdig\fR [@server] [\fB\-b\ \fR\fB\fIaddress\fR\fR] [\fB\-c\ \fR\fB\fIclass\fR\fR] [\fB\-f\ \fR\fB\fIfilename\fR\fR] [\fB\-k\ \fR\fB\fIfilename\fR\fR] [\fB\-m\fR] [\fB\-p\ \fR\fB\fIport#\fR\fR] [\fB\-q\ \fR\fB\fIname\fR\fR] [\fB\-t\ \fR\fB\fItype\fR\fR] [\fB\-v\fR] [\fB\-x\ \fR\fB\fIaddr\fR\fR] [\fB\-y\ \fR\fB\fI[hmac:]\fR\fIname:key\fR\fR] [\fB\-4\fR] [\fB\-6\fR] [name] [type] [class] [queryopt...]
55 \fBdig\fR [global\-queryopt...] [query...]
59 (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
61 to troubleshoot DNS problems because of its flexibility, ease of use and clarity of output\&. Other lookup tools tend to have less functionality than
66 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
68 option is given\&. Unlike earlier versions, the BIND 9 implementation of
70 allows multiple lookups to be issued from the command line\&.
72 Unless it is told to query a specific name server,
74 will try each of the servers listed in
75 /etc/resolv\&.conf\&. If no usable server addresses are found,
77 will send the query to the local host\&.
79 When no command line arguments or options are given,
81 will perform an NS query for "\&." (the root)\&.
83 It is possible to set per\-user defaults for
86 ${HOME}/\&.digrc\&. This file is read and any options in it are applied before the command line arguments\&.
88 The IN and CH class names overlap with the IN and CH top level domain names\&. Either use the
92 options to specify the type and class, use the
94 the specify the domain name, or use "IN\&." and "CH\&." when looking up these top level domains\&.
97 A typical invocation of
105 dig @server name type
115 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
117 argument is a hostname,
119 resolves that name before querying that name server\&.
123 argument is provided,
126 /etc/resolv\&.conf; if an address is found there, it queries the name server at that address\&. If either of the
130 options are in use, then only addresses for the corresponding transport will be tried\&. If no usable addresses are found,
132 will send the query to the local host\&. The reply from the name server that responds is displayed\&.
137 is the name of the resource record that is to be looked up\&.
142 indicates what type of query is required \(em ANY, A, MX, SIG, etc\&.
144 can be any valid query type\&. If no
146 argument is supplied,
148 will perform a lookup for an A record\&.
162 \-b \fIaddress\fR\fI[#port]\fR
164 Set the source IP address of the query\&. The
166 must be a valid address on one of the host\*(Aqs network interfaces, or "0\&.0\&.0\&.0" or "::"\&. An optional port may be specified by appending "#<port>"
171 Set the query class\&. The default
173 is IN; other classes are HS for Hesiod records or CH for Chaosnet records\&.
180 reads a list of lookup requests to process from the given
181 \fIfile\fR\&. Each line in the file should be organized in the same way they would be presented as queries to
183 using the command\-line interface\&.
188 Do reverse IPv6 lookups using the obsolete RFC1886 IP6\&.INT domain, which is no longer in use\&. Obsolete bit string label queries (RFC2874) are not attempted\&.
193 Sign queries using TSIG using a key read from the given file\&. Key files can be generated using
194 \fBtsig-keygen\fR(8)\&. When using TSIG authentication with
195 \fBdig\fR, 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
205 Enable memory usage debugging\&.
210 Send the query to a non\-standard port on the server, instead of the defaut 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\&.
215 The domain name to query\&. This is useful to distinguish the
217 from other arguments\&.
222 The resource record type to query\&. It can be any valid query type which is supported in BIND 9\&. The default query type is "A", unless the
224 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
227 ixfr=N\&. The incremental zone transfer will contain the changes made to the zone since the serial number in the zone\*(Aqs SOA record was
233 Print the version number and exit\&.
238 Simplified reverse lookups, for mapping addresses to names\&. The
240 is an IPv4 address in dotted\-decimal notation, or a colon\-delimited IPv6 address\&. When the
242 is used, there is no need to provide the
249 automatically performs a lookup for a name like
250 94\&.2\&.0\&.192\&.in\-addr\&.arpa
251 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
256 \-y \fI[hmac:]\fR\fIkeyname:secret\fR
258 Sign queries using TSIG with the given authentication key\&.
260 is the name of the key, and
262 is the base64 encoded shared secret\&.
264 is the name of the key algorithm; valid choices are
272 is not specified, the default is
275 NOTE: You should use the
281 the shared secret is supplied as a command line argument in clear text\&. This may be visible in the output from
283 or in a history file maintained by the user\*(Aqs shell\&.
288 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\&.
290 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
292 to negate the meaning of that keyword\&. Other keywords assign values to options like the timeout interval\&. They have the form
293 \fB+keyword=value\fR\&. Keywords may be abbreviated, provided the abbreviation is unambiguous; for example,
296 +cdflag\&. The query options are:
306 Sets the "aa" flag in the query\&.
309 \fB+[no]additional\fR
311 Display [do not display] the additional section of a reply\&. The default is to display it\&.
316 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\&. This bit is set by default\&.
321 Set or clear all display flags\&.
326 Display [do not display] the answer section of a reply\&. The default is to display it\&.
331 Display [do not display] the authority section of a reply\&. The default is to display it\&.
334 \fB+[no]besteffort\fR
336 Attempt to display the contents of messages which are malformed\&. The default is to not display malformed answers\&.
341 Set the UDP message buffer size advertised using EDNS0 to
343 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\&.
348 Set [do not set] the CD (checking disabled) bit in the query\&. This requests the server to not perform DNSSEC validation of responses\&.
353 Display [do not display] the CLASS when printing the record\&.
358 Toggles the printing of the initial comment in the output identifying the version of
360 and the query options that have been applied\&. This comment is printed by default\&.
365 Toggle the display of comment lines in the output\&. The default is to print comments\&.
370 Deprecated, treated as a synonym for
376 Requests DNSSEC records be sent by setting the DNSSEC OK bit (DO) in the OPT record in the additional section of the query\&.
379 \fB+domain=somename\fR
381 Set the search list to contain the single domain
382 \fIsomename\fR, as if specified in a
385 /etc/resolv\&.conf, and enable search list processing as if the
392 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\&.
394 clears the remembered EDNS version\&. EDNS is set to 0 by default\&.
399 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\&.
404 Show [or do not show] the IP address and port number that supplied the answer when the
406 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\&.
411 Ignore truncation in UDP responses instead of retrying with TCP\&. By default, TCP retries are performed\&.
416 Keep the TCP socket open between queries and reuse it rather than creating a new TCP socket for each lookup\&. The default is
422 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
429 Set the number of dots that have to appear in
433 for it to be considered absolute\&. The default value is that defined using the ndots statement in
434 /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
447 Include an EDNS name server ID request when sending a query\&.
452 When this option is set,
454 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\&.
459 Print only one (starting) SOA record when performing an AXFR\&. The default is to print both the starting and ending SOA records\&.
464 Print [do not print] the query as it is sent\&. By default, the query is not printed\&.
469 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\&.
475 \fI+[no]recurse\fR\&.
480 Toggle the setting of the RD (recursion desired) bit in the query\&. This bit is set by default, which means
482 normally sends recursive queries\&. Recursion is automatically disabled when the
486 query options are used\&.
491 Sets the number of times to retry UDP queries to server to
493 instead of the default, 2\&. Unlike
494 \fI+tries\fR, this does not include the initial query\&.
497 \fB+[no]rrcomments\fR
499 Toggle the display of per\-record comments in the output (for example, human\-readable key information about DNSKEY records)\&. The default is not to print record comments unless multiline mode is active\&.
504 Use [do not use] the search list defined by the searchlist or domain directive in
506 (if any)\&. The search list is not used by default\&.
510 (default 1) which may be overridden by
512 determines if the name will be treated as relative or not and hence whether a search is eventually performed or not\&.
517 Provide a terse answer\&. The default is to print the answer in a verbose form\&.
520 \fB+[no]showsearch\fR
522 Perform [do not perform] a search showing intermediate results\&.
527 Chase DNSSEC signature chains\&. Requires dig be compiled with \-DDIG_SIGCHASE\&.
532 Split long hex\- or base64\-formatted fields in resource records into chunks of
536 is rounded up to the nearest multiple of 4)\&.
540 causes fields not to be split at all\&. The default is 56 characters, or 44 characters when multiline mode is active\&.
545 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\&.
550 Use [do not use] TCP when querying name servers\&. The default behavior is to use UDP unless an
552 query is requested, in which case the default is TCP\&. AXFR queries always use TCP\&.
557 Sets the timeout for a query to
559 seconds\&. The default timeout is 5 seconds\&. An attempt to set
561 to less than 1 will result in a query timeout of 1 second being applied\&.
566 When chasing DNSSEC signature chains perform a top\-down validation\&. Requires dig be compiled with \-DDIG_SIGCHASE\&.
571 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,
573 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\&.
575 If @server is also specified, it affects only the initial query for the root zone name servers\&.
578 is also set when +trace is set to better emulate the default queries from a nameserver\&.
583 Sets the number of times to try UDP queries to server to
585 instead of the default, 3\&. If
587 is less than or equal to zero, the number of tries is silently rounded up to 1\&.
590 \fB+trusted\-key=####\fR
592 Specifies a file containing trusted keys to be used with
593 \fB+sigchase\fR\&. Each DNSKEY record must be on its own line\&.
598 /etc/trusted\-key\&.key
601 in the current directory\&.
603 Requires dig be compiled with \-DDIG_SIGCHASE\&.
608 Display [do not display] the TTL when printing the record\&.
613 Use [do not use] TCP when querying name servers\&. This alternate syntax to
615 is provided for backwards compatibility\&. The "vc" stands for "virtual circuit"\&.
617 .SH "MULTIPLE QUERIES"
619 The BIND 9 implementation of
621 supports specifying multiple queries on the command line (in addition to supporting the
623 batch file option)\&. Each of those queries can be supplied with its own set of flags, options and query options\&.
627 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\&.
629 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
631 option) can be overridden by a query\-specific set of query options\&. For example:
637 dig +qr www\&.isc\&.org any \-x 127\&.0\&.0\&.1 isc\&.org ns +noqr
645 could be used from the command line to make three lookups: an ANY query for
646 www\&.isc\&.org, a reverse lookup of 127\&.0\&.0\&.1 and a query for the NS records of
647 isc\&.org\&. A global query option of
651 shows the initial query it made for each lookup\&. The final query has a local query option of
655 will not print the initial query when it looks up the NS records for
661 has been built with IDN (internationalized domain name) support, it can accept and display non\-ASCII domain names\&.
663 appropriately converts character encoding of domain name before sending a request to DNS server or displaying a reply from the server\&. If you\*(Aqd like to turn off the IDN support for some reason, defines the
665 environment variable\&. The IDN support is disabled if the variable is set when
677 \fBdnssec-keygen\fR(8),
681 There are probably too many query options\&.
684 \fBInternet Systems Consortium, Inc\&.\fR
687 Copyright \(co 2004-2011, 2013-2015 Internet Systems Consortium, Inc. ("ISC")
689 Copyright \(co 2000-2003 Internet Software Consortium.