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diff --git a/bin/dig/dig.rst b/bin/dig/dig.rst new file mode 100644 index 0000000..59ac9f1 --- /dev/null +++ b/bin/dig/dig.rst @@ -0,0 +1,809 @@ +.. Copyright (C) Internet Systems Consortium, Inc. ("ISC") +.. +.. SPDX-License-Identifier: MPL-2.0 +.. +.. This Source Code Form is subject to the terms of the Mozilla Public +.. License, v. 2.0. If a copy of the MPL was not distributed with this +.. file, you can obtain one at https://mozilla.org/MPL/2.0/. +.. +.. See the COPYRIGHT file distributed with this work for additional +.. information regarding copyright ownership. + +.. highlight: console + +.. iscman:: dig +.. program:: dig +.. _man_dig: + +dig - DNS lookup utility +------------------------ + +Synopsis +~~~~~~~~ +:program:`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...] + +:program:`dig` [**-h**] + +:program:`dig` [global-queryopt...] [query...] + +Description +~~~~~~~~~~~ + +:program:`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 :program:`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 :program:`dig`. + +Although :program:`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 :option:`-h` option is given. The BIND 9 +implementation of :program:`dig` allows multiple lookups to be issued from the +command line. + +Unless it is told to query a specific name server, :program:`dig` tries each +of the servers listed in ``/etc/resolv.conf``. If no usable server +addresses are found, :program:`dig` sends the query to the local host. + +When no command-line arguments or options are given, :program:`dig` +performs an NS query for "." (the root). + +It is possible to set per-user defaults for :program:`dig` via +``${HOME}/.digrc``. This file is read and any options in it are applied +before the command-line arguments. The :option:`-r` option disables this +feature, for scripts that need predictable behavior. + +The IN and CH class names overlap with the IN and CH top-level domain +names. Either use the :option:`-t` and :option:`-c` options to specify the type and +class, use the :option:`-q` to specify the domain name, or use "IN." and +"CH." when looking up these top-level domains. + +Simple Usage +~~~~~~~~~~~~ + +A typical invocation of :program:`dig` looks like: + +:: + + dig @server name type + +where: + +.. option:: 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, :program:`dig` resolves that name before querying that name + server. + + If no ``server`` argument is provided, :program:`dig` consults + ``/etc/resolv.conf``; if an address is found there, it queries the + name server at that address. If either of the :option:`-4` or :option:`-6` + options are in use, then only addresses for the corresponding + transport are tried. If no usable addresses are found, :program:`dig` + sends the query to the local host. The reply from the name server + that responds is displayed. + +.. option:: name + + is the name of the resource record that is to be looked up. + +.. option:: 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, :program:`dig` performs a lookup for an A record. + +Options +~~~~~~~ + +.. option:: -4 + + This option indicates that only IPv4 should be used. + +.. option:: -6 + + This option indicates that only IPv6 should be used. + +.. option:: -b address[#port] + + This option sets 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``. + +.. option:: -c class + + This option sets the query class. The default ``class`` is IN; other classes are + HS for Hesiod records or CH for Chaosnet records. + +.. option:: -f file + + This option sets batch mode, in which :program:`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 it would be presented as a query to :program:`dig` using the + command-line interface. + +.. option:: -h + + Print a usage summary. + +.. option:: -k keyfile + + This option tells :program:`dig` to sign queries using TSIG or + SIG(0) using a key read from the given file. Key files can be + generated using :iscman:`tsig-keygen`. When using TSIG authentication + with :program:`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 :iscman:`named.conf` for TSIG and by looking up the KEY record + in zone data for SIG(0). + +.. option:: -m + + This option enables memory usage debugging. + +.. option:: -p port + + This option sends the query to a non-standard port on the server, instead of the + default port 53. This option is used to test a name server that + has been configured to listen for queries on a non-standard port + number. + +.. option:: -q name + + This option specifies the domain name to query. This is useful to distinguish the ``name`` + from other arguments. + +.. option:: -r + + This option indicates that options from ``${HOME}/.digrc`` should not be read. This is useful for + scripts that need predictable behavior. + +.. option:: -t type + + This option indicates the resource record type to query, which 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 :option:`-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 contains + all 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 is displayed as described in :rfc:`3597`. + +.. option:: -u + + This option indicates that print query times should be provided in microseconds instead of milliseconds. + +.. option:: -v + + This option prints the version number and exits. + +.. option:: -x addr + + This option sets 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 :option:`-x` option is used, there is no + need to provide the ``name``, ``class``, and ``type`` arguments. + :program:`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. + +.. option:: -y [hmac:]keyname:secret + + This option signs 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``; if MD5 was disabled, the default is + ``hmac-sha256``. + +.. note:: Only the :option:`-k` option should be used, rather than the :option:`-y` option, + because with :option:`-y` the shared secret is supplied as a command-line + argument in clear text. This may be visible in the output from ``ps1`` or + in a history file maintained by the user's shell. + +Query Options +~~~~~~~~~~~~~ + +:program:`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, :option:`+cd` is equivalent to +:option:`+cdflag`. The query options are: + +.. option:: +aaflag, +noaaflag + + This option is a synonym for :option:`+aaonly`, :option:`+noaaonly`. + +.. option:: +aaonly, +noaaonly + + This option sets the ``aa`` flag in the query. + +.. option:: +additional, +noadditional + + This option displays [or does not display] the additional section of a reply. The + default is to display it. + +.. option:: +adflag, +noadflag + + This option sets [or does 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 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`` + indicates that some part of the answer was insecure or not validated. + This bit is set by default. + +.. option:: +all, +noall + + This option sets or clears all display flags. + +.. option:: +answer, +noanswer + + This option displays [or does not display] the answer section of a reply. The default + is to display it. + +.. option:: +authority, +noauthority + + This option displays [or does not display] the authority section of a reply. The + default is to display it. + +.. option:: +badcookie, +nobadcookie + + This option retries the lookup with a new server cookie if a BADCOOKIE response is + received. + +.. option:: +besteffort, +nobesteffort + + This option attempts to display the contents of messages which are malformed. The + default is to not display malformed answers. + +.. option:: +bufsize[=B] + + This option sets the UDP message buffer size advertised using EDNS0 to + ``B`` bytes. The maximum and minimum sizes of this buffer are 65535 and + 0, respectively. ``+bufsize`` restores the default buffer size. + +.. option:: +cd, +cdflag, +nocdflag + + This option sets [or does not set] the CD (checking disabled) bit in the query. This + requests the server to not perform DNSSEC validation of responses. + +.. option:: +class, +noclass + + This option displays [or does not display] the CLASS when printing the record. + +.. option:: +cmd, +nocmd + + This option toggles the printing of the initial comment in the output, identifying the + version of :program:`dig` and the query options that have been applied. This option + always has a global effect; it cannot be set globally and then overridden on a + per-lookup basis. The default is to print this comment. + +.. option:: +comments, +nocomments + + This option toggles the display of some comment lines in the output, with + information about the packet header and OPT pseudosection, and the names of + the response section. The default is to print these comments. + + Other types of comments in the output are not affected by this option, but + can be controlled using other command-line switches. These include + :option:`+cmd`, :option:`+question`, :option:`+stats`, and :option:`+rrcomments`. + +.. option:: +cookie=####, +nocookie + + This option sends [or does not send] a COOKIE EDNS option, with an optional value. Replaying a COOKIE + from a previous response allows the server to identify a previous + client. The default is ``+cookie``. + + ``+cookie`` is also set when :option:`+trace` is set to better emulate the + default queries from a nameserver. + +.. option:: +crypto, +nocrypto + + This option toggles the display of cryptographic fields in DNSSEC records. The + contents of these fields are unnecessary for debugging 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 ]``. + +.. option:: +defname, +nodefname + + This option, which is deprecated, is treated as a synonym for + :option:`+search`, :option:`+nosearch`. + +.. option:: +dns64prefix, +nodns64prefix + + Lookup IPV4ONLY.ARPA AAAA and print any DNS64 prefixes found. + +.. option:: +dnssec, +do, +nodnssec, +nodo + + This option requests that DNSSEC records be sent by setting the DNSSEC OK (DO) bit in + the OPT record in the additional section of the query. + +.. option:: +domain=somename + + This option sets the search list to contain the single domain ``somename``, as if + specified in a ``domain`` directive in ``/etc/resolv.conf``, and + enables search list processing as if the :option:`+search` option were + given. + +.. option:: +dscp=value + + This option formerly set the DSCP value used when sending a query. + It is now obsolete, and has no effect. + +.. option:: +edns[=#], +noedns + + This option specifies the EDNS version to query with. Valid values are 0 to 255. + Setting the EDNS version causes an EDNS query to be sent. + ``+noedns`` clears the remembered EDNS version. EDNS is set to 0 by + default. + +.. option:: +ednsflags[=#], +noednsflags + + This option sets 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) is silently ignored. By default, no Z bits are set. + +.. option:: +ednsnegotiation, +noednsnegotiation + + This option enables/disables EDNS version negotiation. By default, EDNS version + negotiation is enabled. + +.. option:: +ednsopt[=code[:value]], +noednsopt + + This option specifies the EDNS option with code point ``code`` and an optional 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. + +.. option:: +expire, +noexpire + + This option sends an EDNS Expire option. + +.. option:: +fail, +nofail + + This option indicates that :iscman:`named` should try [or not try] the next server if a SERVFAIL is received. The default is + to not try the next server, which is the reverse of normal stub + resolver behavior. + +.. option:: +fuzztime[=value], +nofuzztime + + This option allows the signing time to be specified when generating + signed messages. If a value is specified it is the seconds since + 00:00:00 January 1, 1970 UTC ignoring leap seconds. If no value + is specified 1646972129 (Fri 11 Mar 2022 04:15:29 UTC) is used. + The default is ``+nofuzztime`` and the current time is used. + +.. option:: +header-only, +noheader-only + + This option sends 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. + +.. option:: +https[=value], +nohttps + + This option indicates whether to use DNS over HTTPS (DoH) when querying + name servers. When this option is in use, the port number defaults to 443. + The HTTP POST request mode is used when sending the query. + + If ``value`` is specified, it will be used as the HTTP endpoint in the + query URI; the default is ``/dns-query``. So, for example, ``dig + @example.com +https`` will use the URI ``https://example.com/dns-query``. + +.. option:: +https-get[=value], +nohttps-get + + Similar to :option:`+https`, except that the HTTP GET request mode is used + when sending the query. + +.. option:: +https-post[=value], +nohttps-post + + Same as :option:`+https`. + +.. option:: +http-plain[=value], +nohttp-plain + + Similar to :option:`+https`, except that HTTP queries will be sent over a + non-encrypted channel. When this option is in use, the port number + defaults to 80 and the HTTP request mode is POST. + +.. option:: +http-plain-get[=value], +nohttp-plain-get + + Similar to :option:`+http-plain`, except that the HTTP request mode is GET. + +.. option:: +http-plain-post[=value], +nohttp-plain-post + + Same as :option:`+http-plain`. + +.. option:: +identify, +noidentify + + This option shows [or does not show] the IP address and port number that + supplied the answer, when the :option:`+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. + +.. option:: +idnin, +noidnin + + This option processes [or does 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 when standard output is a tty. + The IDN processing on input is disabled when :program:`dig` output is redirected + to files, pipes, and other non-tty file descriptors. + +.. option:: +idnout, +noidnout + + This option converts [or does not convert] puny code on output. This requires + ``IDN SUPPORT`` to have been enabled at compile time. + + The default is to process puny code on output when standard output is + a tty. The puny code processing on output is disabled when :program:`dig` output + is redirected to files, pipes, and other non-tty file descriptors. + +.. option:: +ignore, +noignore + + This option ignores [or does not ignore] truncation in UDP responses instead of retrying with TCP. By + default, TCP retries are performed. + +.. option:: +keepalive, +nokeepalive + + This option sends [or does not send] an EDNS Keepalive option. + +.. option:: +keepopen, +nokeepopen + + This option keeps [or does not keep] the TCP socket open between queries, and reuses it rather than + creating a new TCP socket for each lookup. The default is + ``+nokeepopen``. + +.. option:: +multiline, +nomultiline + + This option prints [or does not 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 :program:`dig` output. + +.. option:: +ndots=D + + This option sets the number of dots (``D``) that must appear in ``name`` 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 are searched for in the domains listed in the + ``search`` or ``domain`` directive in ``/etc/resolv.conf`` if + :option:`+search` is set. + +.. option:: +nsid, +nonsid + + When enabled, this option includes an EDNS name server ID request when sending a query. + +.. option:: +nssearch, +nonssearch + + When this option is set, :program:`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. + Addresses of servers that did not respond are also printed. + +.. option:: +onesoa, +noonesoa + + When enabled, this option prints only one (starting) SOA record when performing an AXFR. The + default is to print both the starting and ending SOA records. + +.. option:: +opcode=value, +noopcode + + When enabled, this option sets (restores) the DNS message opcode to the specified value. The + default value is QUERY (0). + +.. option:: +padding=value + + This option pads the size of the query packet using the EDNS Padding option to + blocks of ``value`` bytes. For example, ``+padding=32`` causes a + 48-byte query to be padded to 64 bytes. The default block size is 0, + which disables padding; the maximum is 512. Values are ordinarily + expected to be powers of two, such as 128; however, this is not + mandatory. Responses to padded queries may also be padded, but only + if the query uses TCP or DNS COOKIE. + +.. option:: +qid=value + + This option specifies the query ID to use when sending queries. + +.. option:: +qr, +noqr + + This option toggles the display of the query message as it is sent. By default, the query + is not printed. + +.. option:: +question, +noquestion + + This option toggles the display of the question section of a query when an answer is + returned. The default is to print the question section as a comment. + +.. option:: +raflag, +noraflag + + This option sets [or does not set] the RA (Recursion Available) bit in the query. The + default is ``+noraflag``. This bit is ignored by the server for + QUERY. + +.. option:: +rdflag, +nordflag + + This option is a synonym for :option:`+recurse`, :option:`+norecurse`. + +.. option:: +recurse, +norecurse + + This option toggles the setting of the RD (recursion desired) bit in the query. + This bit is set by default, which means :program:`dig` normally sends + recursive queries. Recursion is automatically disabled when the + :option:`+nssearch` or :option:`+trace` query option is used. + +.. option:: +retry=T + + This option sets the number of times to retry UDP and TCP queries to server to ``T`` + instead of the default, 2. Unlike :option:`+tries`, this does not include + the initial query. + +.. option:: +rrcomments, +norrcomments + + This option toggles 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. + +.. option:: +search, +nosearch + + This option uses [or does 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 + :option:`+ndots`, determines whether the name is treated as relative + and hence whether a search is eventually performed. + +.. option:: +short, +noshort + + This option toggles whether a terse answer is provided. The default is to print the answer in a verbose + form. This option always has a global effect; it cannot be set globally and + then overridden on a per-lookup basis. + +.. option:: +showbadcookie, +noshowbadcookie + + This option toggles whether to show the message containing the + BADCOOKIE rcode before retrying the request or not. The default + is to not show the messages. + +.. option:: +showsearch, +noshowsearch + + This option performs [or does not perform] a search showing intermediate results. + +.. option:: +sigchase, +nosigchase + + This feature is now obsolete and has been removed; use :iscman:`delv` + instead. + +.. option:: +split=W + + This option splits 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. + +.. option:: +stats, +nostats + + This option toggles the printing of statistics: when the query was made, the size of the + reply, etc. The default behavior is to print the query statistics as a + comment after each lookup. + +.. option:: +subnet=addr[/prefix-length], +nosubnet + + This option sends [or does not 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. + +.. option:: +tcflag, +notcflag + + This option sets [or does not set] the TC (TrunCation) bit in the query. The default is + ``+notcflag``. This bit is ignored by the server for QUERY. + +.. option:: +tcp, +notcp + + This option indicates whether to 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. To prevent retry over TCP when + TC=1 is returned from a UDP query, use ``+ignore``. + +.. option:: +timeout=T + + This option sets the timeout for a query to ``T`` seconds. The default timeout is + 5 seconds. An attempt to set ``T`` to less than 1 is silently set to 1. + +.. option:: +tls, +notls + + This option indicates whether to use DNS over TLS (DoT) when querying + name servers. When this option is in use, the port number defaults + to 853. + +.. option:: +tls-ca[=file-name], +notls-ca + + This option enables remote server TLS certificate validation for + DNS transports, relying on TLS. Certificate authorities + certificates are loaded from the specified PEM file + (``file-name``). If the file is not specified, the default + certificates from the global certificates store are used. + +.. option:: +tls-certfile=file-name, +tls-keyfile=file-name, +notls-certfile, +notls-keyfile + + These options set the state of certificate-based client + authentication for DNS transports, relying on TLS. Both certificate + chain file and private key file are expected to be in PEM format. + Both options must be specified at the same time. + +.. option:: +tls-hostname=hostname, +notls-hostname + + This option makes :program:`dig` use the provided hostname during remote + server TLS certificate verification. Otherwise, the DNS server name + is used. This option has no effect if :option:`+tls-ca` is not specified. + +.. option:: +topdown, +notopdown + + This feature is related to :option:`dig +sigchase`, which is obsolete and + has been removed. Use :iscman:`delv` instead. + +.. option:: +trace, +notrace + + This option toggles 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, :program:`dig` makes iterative queries to resolve the + name being looked up. It follows 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. + + :option:`+dnssec` is also set when :option:`+trace` is set, to better emulate the + default queries from a name server. + +.. option:: +tries=T + + This option sets the number of times to try UDP and TCP 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. + +.. option:: +trusted-key=#### + + This option formerly specified trusted keys for use with :option:`dig +sigchase`. This + feature is now obsolete and has been removed; use :iscman:`delv` instead. + +.. option:: +ttlid, +nottlid + + This option displays [or does not display] the TTL when printing the record. + +.. option:: +ttlunits, +nottlunits + + This option displays [or does not display] the TTL in friendly human-readable time + units of ``s``, ``m``, ``h``, ``d``, and ``w``, representing seconds, minutes, + hours, days, and weeks. This implies :option:`+ttlid`. + +.. option:: +unknownformat, +nounknownformat + + This option prints 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. + +.. option:: +vc, +novc + + This option uses [or does not use] TCP when querying name servers. This alternate + syntax to :option:`+tcp` is provided for backwards compatibility. The + ``vc`` stands for "virtual circuit." + +.. option:: +yaml, +noyaml + + When enabled, this option prints the responses (and, if :option:`+qr` is in use, also the + outgoing queries) in a detailed YAML format. + +.. option:: +zflag, +nozflag + + This option sets [or does 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 :program:`dig` supports specifying multiple +queries on the command line (in addition to supporting the :option:`-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 represents 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 :option:`+cmd` and +:option:`+short` options) 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 :program:`dig` can 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 +:option:`+qr` is applied, so that :program:`dig` shows the initial query it made for +each lookup. The final query has a local query option of :option:`+noqr` which +means that :program:`dig` does not print the initial query when it looks up the +NS records for ``isc.org``. + +IDN Support +~~~~~~~~~~~ + +If :program:`dig` has been built with IDN (internationalized domain name) +support, it can accept and display non-ASCII domain names. :program:`dig` +appropriately converts character encoding of a domain name before sending +a request to a DNS server or displaying a reply from the server. +To turn off IDN support, use the parameters +:option:`+idnin` and :option:`+idnout`, or define the ``IDN_DISABLE`` environment +variable. + +Return Codes +~~~~~~~~~~~~ + +:program:`dig` return codes are: + +``0`` + DNS response received, including NXDOMAIN status + +``1`` + Usage error + +``8`` + Couldn't open batch file + +``9`` + No reply from server + +``10`` + Internal error + +Files +~~~~~ + +``/etc/resolv.conf`` + +``${HOME}/.digrc`` + +See Also +~~~~~~~~ + +:iscman:`delv(1) <delv>`, :iscman:`host(1) <host>`, :iscman:`named(8) <named>`, :iscman:`dnssec-keygen(8) <dnssec-keygen>`, :rfc:`1035`. + +Bugs +~~~~ + +There are probably too many query options. |