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dig(1)                               BIND9                              dig(1)


       dig - DNS lookup utility


       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...]


       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. 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 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.


       A typical invocation of dig looks like:

            dig @server name type


           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;
           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.

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

           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.


           Use IPv4 only.

           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 "" or
           "::". An optional port may be specified by appending "#<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.

           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.

       -k keyfile
           Sign queries using TSIG using a key read from the given file. Key
           files can be generated using tsig-keygen(8). 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

           Enable memory usage debugging.

       -p port
           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.

       -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
           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, 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.

           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 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-md5, hmac-sha1, hmac-sha224, hmac-sha256, hmac-sha384, or
           hmac-sha512. If hmac is not specified, the default is hmac-md5.

           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 ps(1) or in a
           history file maintained by the user's shell.


       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

       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
       options are:

           A synonym for +[no]aaonly.

           Sets the "aa" flag in the query.

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

           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.

           Set or clear all display flags.

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

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

           Attempt to display the contents of messages which are malformed.
           The default is to not display malformed answers.

           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

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

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

           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.

           Toggle the display of comment lines in the output. The default is
           to print comments.

           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

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

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

           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.

           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

           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.

           Enable / disable EDNS version negotiation. By default EDNS version
           negotiation is enabled.

           Specify EDNS option with code point code and optionally payload of
           value as a hexadecimal string.  +noednsopt clears the EDNS options
           to to be sent.

           Send an EDNS Expire option.

           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.

           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.

           Ignore truncation in UDP responses instead of retrying with TCP. By
           default, TCP retries are performed.

           Keep the TCP socket open between queries and reuse it rather than
           creating a new TCP socket for each lookup. The default is

           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.

           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 if +search is set.

           Include an EDNS name server ID request when sending a query.

           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.

           Print only one (starting) SOA record when performing an AXFR. The
           default is to print both the starting and ending SOA records.

           Set [restore] the DNS message opcode to the specified value. The
           default value is QUERY (0).

           Print [do not print] the query as it is sent. By default, the query
           is not printed.

           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

           A synonym for +[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.

           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.

           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

           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.

           Provide a terse answer. The default is to print the answer in a
           verbose form.

           Perform [do not perform] a search showing intermediate results.

           Chase DNSSEC signature chains. Requires dig be compiled with

           Send a Source Identity Token EDNS option, with optional value.
           Replaying a SIT from a previous response will allow the server to
           identify a previous client. The default is +nosit. Currently using
           experimental value 65001 for the option code.

           Split long hex- or base64-formatted fields in resource records into
           chunks of W characters (where W 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.

           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.

           Send an EDNS Client Subnet option with the specified IP address or
           network prefix.

           Use [do not use] TCP when querying name servers. The default
           behavior is to use UDP unless an ixfr=N query is requested, in
           which case the default is TCP. AXFR queries always use TCP.

           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.

           When chasing DNSSEC signature chains perform a top-down validation.
           Requires dig be compiled with -DDIG_SIGCHASE.

           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

           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
           default queries from a nameserver.

           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.

           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.

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

           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".


       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

       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

           dig +qr any -x ns +noqr

       shows how dig could be used from the command line to make three
       lookups: an ANY query for, a reverse lookup of
       and a query for the NS records of 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


       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.





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


       There are probably too many query options.


       Copyright (C) 2004-2011, 2013-2015 Internet Systems Consortium, Inc.
       Copyright (C) 2000-2003 Internet Software Consortium.

BIND9                          February 19, 2014                        dig(1)

bind 9.10.3 - Generated Thu Sep 17 18:58:22 CDT 2015
© 2000-2015
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