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] [-v] [-x addr] [-y [hmac:]name:key] [[-4] |
           [-6]] [name] [type] [class] [queryopt...]

       dig [-h]

       dig [global-queryopt...] [query...]

DESCRIPTION
       dig 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.

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; 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.

       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
       -4
           Use IPv4 only.

       -6
           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 "0.0.0.0" 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.

       -i
           Do reverse IPv6 lookups using the obsolete RFC 1886 IP6.INT domain, which is
           no longer in use. Obsolete bit string label queries (RFC 2874) 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 named.conf.

       -m
           Enable memory usage debugging.

       -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 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.

           All resource record types can be expressed as "TYPEnn", where "nn" is the
           number of the type. If the resource record type is not supported 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-md5, hmac-sha1,
           hmac-sha224, hmac-sha256, hmac-sha384, or hmac-sha512. If hmac is not
           specified, the default is hmac-md5 or if MD5 was disabled hmac-sha256.

           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.

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. Keywords may be
       abbreviated, provided the abbreviation is unambiguous; for example, +cd is
       equivalent to +cdflag. The query options are:

       +[no]aaflag
           A synonym for +[no]aaonly.

       +[no]aaonly
           Sets the "aa" flag in the query.

       +[no]additional
           Display [do not display] the additional section of a reply. The default is
           to display it.

       +[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. This bit is set by default.

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

       +[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]badcookie
           Retry lookup with the new server cookie if a BADCOOKIE response is received.

       +[no]besteffort
           Attempt to display the contents of messages which are malformed. The default
           is to not display malformed answers.

       +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.

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

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

       +[no]cookie[=####]
           Send a COOKIE EDNS option, with optional value. Replaying a COOKIE from a
           previous response will allow the server to identify a previous client. The
           default is +cookie.

           +cookie is also set when +trace is set to better emulate the default queries
           from a nameserver.

       +[no]crypto
           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 ]".

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

       +[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.

       +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.

       +dscp=value
           Set the DSCP code point to be used when sending the query. Valid DSCP code
           points are in the range [0..63]. By default no code point is explicitly set.

       +[no]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. EDNS is set to 0 by default.

       +[no]ednsflags[=#]
           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.

       +[no]ednsnegotiation
           Enable / disable EDNS version negotiation. By default EDNS version
           negotiation is enabled.

       +[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 option 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.

       +[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]header-only
           Send a query with a DNS header without a question section. The default is to
           add a question section. The query type and query name are ignored when this
           is set.

       +[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]idnin
           Process [do not process] IDN domain names on input. This requires IDN
           SUPPORT to have been enabled at compile time. The default is to process IDN
           input.

       +[no]idnout
           Convert [do not convert] puny code on output. This requires IDN SUPPORT to
           have been enabled at compile time. The default is to convert output.

       +[no]ignore
           Ignore truncation in UDP responses instead of retrying with TCP. By default,
           TCP retries are performed.

       +[no]keepopen
           Keep the TCP socket open between queries and reuse it rather than creating a
           new TCP socket for each lookup. The default is +nokeepopen.

       +[no]mapped
           Allow mapped IPv4 over IPv6 addresses to be used. The default is +mapped.

       +[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.

       +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
           if +search is set.

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

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

       +[no]opcode=value
           Set [restore] the DNS message opcode to the specified value. The default
           value is QUERY (0).

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

       +[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.

       +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.

       +[no]rrcomments
           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.

       +[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.

           '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.

       +[no]short
           Provide a terse answer. The default is to print the answer in a verbose
           form.

       +[no]showsearch
           Perform [do not perform] a search showing intermediate results.

       +[no]sigchase
           Chase DNSSEC signature chains. Requires dig be compiled with -DDIG_SIGCHASE.
           This feature is deprecated. Use delv instead.

       +split=W
           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.

       +[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]subnet=addr[/prefix-length]
           Send (don't send) an EDNS Client Subnet option with the specified IP address
           or network prefix.

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

       +timeout=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.

       +[no]topdown
           When chasing DNSSEC signature chains perform a top-down validation. Requires
           dig be compiled with -DDIG_SIGCHASE. This feature is deprecated. Use delv
           instead.

       +[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.

           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.

       +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.

       +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. This feature is deprecated.
           Use delv instead.

       +[no]ttlid
           Display [do not display] the TTL when printing the record.

       +[no]ttlunits
           Display [do not display] the TTL in friendly human-readable time units of
           "s", "m", "h", "d", and "w", representing seconds, minutes, hours, days and
           weeks. Implies +ttlid.

       +[no]unknownformat
           Print all RDATA in unknown RR type presentation format (RFC 3597). The
           default is to print RDATA for known types in the type's presentation format.

       +[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]zflag
           Set [do not set] the last unassigned DNS header flag in a DNS query. This
           flag is off by default.

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, use parameters +noidnin and +noidnout.

FILES
       /etc/resolv.conf

       ${HOME}/.digrc

SEE ALSO
       delv(1), host(1), named(8), dnssec-keygen(8), RFC 1035.

BUGS
       There are probably too many query options.

AUTHOR
       Internet Systems Consortium, Inc.

COPYRIGHT
       Copyright © 2000-2011, 2013-2019 Internet Systems Consortium, Inc. ("ISC")

ISC                                    2014-02-19                                DIG(1)

Usage:  dig [@global-server] [domain] [q-type] [q-class] {q-opt}
            {global-d-opt} host [@local-server] {local-d-opt}
            [ host [@local-server] {local-d-opt} [...]]
Where:  domain    is in the Domain Name System
        q-class  is one of (in,hs,ch,...) [default: in]
        q-type   is one of (a,any,mx,ns,soa,hinfo,axfr,txt,...) [default:a]
                 (Use ixfr=version for type ixfr)
        q-opt    is one of:
                 -4                  (use IPv4 query transport only)
                 -6                  (use IPv6 query transport only)
                 -b address[#port]   (bind to source address/port)
                 -c class            (specify query class)
                 -f filename         (batch mode)
                 -i                  (use IP6.INT for IPv6 reverse lookups)
                 -k keyfile          (specify tsig key file)
                 -m                  (enable memory usage debugging)
                 -p port             (specify port number)
                 -q name             (specify query name)
                 -t type             (specify query type)
                 -u                  (display times in usec instead of msec)
                 -x dot-notation     (shortcut for reverse lookups)
                 -y [hmac:]name:key  (specify named base64 tsig key)
        d-opt    is of the form +keyword[=value], where keyword is:
                 +[no]aaflag         (Set AA flag in query (+[no]aaflag))
                 +[no]aaonly         (Set AA flag in query (+[no]aaflag))
                 +[no]additional     (Control display of additional section)
                 +[no]adflag         (Set AD flag in query (default on))
                 +[no]all            (Set or clear all display flags)
                 +[no]answer         (Control display of answer section)
                 +[no]authority      (Control display of authority section)
                 +[no]badcookie      (Retry BADCOOKIE responses)
                 +[no]besteffort     (Try to parse even illegal messages)
                 +bufsize=###        (Set EDNS0 Max UDP packet size)
                 +[no]cdflag         (Set checking disabled flag in query)
                 +[no]class          (Control display of class in records)
                 +[no]cmd            (Control display of command line)
                 +[no]comments       (Control display of comment lines)
                 +[no]cookie         (Add a COOKIE option to the request)
                 +[no]crypto         (Control display of cryptographic fields in records)
                 +[no]defname        (Use search list (+[no]search))
                 +[no]dnssec         (Request DNSSEC records)
                 +domain=###         (Set default domainname)
                 +[no]dscp[=###]     (Set the DSCP value to ### [0..63])
                 +[no]edns[=###]     (Set EDNS version) [0]
                 +ednsflags=###      (Set EDNS flag bits)
                 +[no]ednsnegotiation (Set EDNS version negotiation)
                 +ednsopt=###[:value] (Send specified EDNS option)
                 +noednsopt          (Clear list of +ednsopt options)
                 +[no]expire         (Request time to expire)
                 +[no]fail           (Don't try next server on SERVFAIL)
                 +[no]header-only    (Send query without a question section)
                 +[no]identify       (ID responders in short answers)
                 +[no]idnin          (Parse IDN names)
                 +[no]idnout         (Convert IDN response)
                 +[no]ignore         (Don't revert to TCP for TC responses.)
                 +[no]keepopen       (Keep the TCP socket open between queries)
                 +[no]mapped         (Allow mapped IPv4 over IPv6)
                 +[no]multiline      (Print records in an expanded format)
                 +ndots=###          (Set search NDOTS value)
                 +[no]nsid           (Request Name Server ID)
                 +[no]nssearch       (Search all authoritative nameservers)
                 +[no]onesoa         (AXFR prints only one soa record)
                 +[no]opcode=###     (Set the opcode of the request)
                 +[no]qr             (Print question before sending)
                 +[no]question       (Control display of question section)
                 +[no]rdflag         (Recursive mode (+[no]recurse))
                 +[no]recurse        (Recursive mode (+[no]rdflag))
                 +retry=###          (Set number of UDP retries) [2]
                 +[no]rrcomments     (Control display of per-record comments)
                 +[no]search         (Set whether to use searchlist)
                 +[no]short          (Display nothing except short
                                      form of answer)
                 +[no]showsearch     (Search with intermediate results)
                 +[no]sigchase       (Chase DNSSEC signatures)
                 +[no]split=##       (Split hex/base64 fields into chunks)
                 +[no]stats          (Control display of statistics)
                 +subnet=addr        (Set edns-client-subnet option)
                 +[no]tcp            (TCP mode (+[no]vc))
                 +timeout=###        (Set query timeout) [5]
                 +[no]topdown        (Do +sigchase in top-down mode)
                 +[no]trace          (Trace delegation down from root [+dnssec])
                 +trusted-key=####   (Trusted Key to use with +sigchase)
                 +tries=###          (Set number of UDP attempts) [3]
                 +[no]ttlid          (Control display of ttls in records)
                 +[no]ttlunits       (Display TTLs in human-readable units)
                 +[no]unknownformat  (Print RDATA in RFC 3597 "unknown" format)
                 +[no]vc             (TCP mode (+[no]tcp))
                 +[no]zflag          (Set Z flag in query)
        global d-opts and servers (before host name) affect all queries.
        local d-opts and servers (after host name) affect only that lookup.
        -h                           (print help and exit)
        -v                           (print version and exit)