{ "mode": "man", "parameter": "MDIG", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/MDIG/1/json", "generated": "2026-07-05T02:10:50Z", "synopsis": "mdig {@server} [-f filename] [-h] [-v] [ [-4] | [-6] ] [-m] [-b address] [-p port#] [-c\nclass] [-t type] [-i] [-x addr] [plusopt...]\nmdig {-h}\nmdig [@server] {global-opt...} { {local-opt...} {query} ...}", "sections": { "NAME": { "content": "mdig - DNS pipelined lookup utility\n", "subsections": [] }, "SYNOPSIS": { "content": "mdig {@server} [-f filename] [-h] [-v] [ [-4] | [-6] ] [-m] [-b address] [-p port#] [-c\nclass] [-t type] [-i] [-x addr] [plusopt...]\n\nmdig {-h}\n\nmdig [@server] {global-opt...} { {local-opt...} {query} ...}\n", "subsections": [] }, "DESCRIPTION": { "content": "mdig is a multiple/pipelined query version of dig: instead of waiting for a response after\nsending each query, it begins by sending all queries. Responses are displayed in the order in\nwhich they are received, not in the order the corresponding queries were sent.\n\nmdig options are a subset of the dig options, and are divided into \"anywhere options,\" which\ncan occur anywhere, \"global options,\" which must occur before the query name (or they are ig‐\nnored with a warning), and \"local options,\" which apply to the next query on the command\nline.\n\nThe @server option is a mandatory global option. It is the name or IP address of the name\nserver to query. (Unlike dig, this value is not retrieved from /etc/resolv.conf.) It can be\nan IPv4 address in dotted-decimal notation, an IPv6 address in colon-delimited notation, or a\nhostname. When the supplied server argument is a hostname, mdig resolves that name before\nquerying the name server.\n\nmdig provides a number of query options which affect the way in which lookups are made and\nthe results displayed. Some of these set or reset flag bits in the query header, some deter‐\nmine which sections of the answer get printed, and others determine the timeout and retry\nstrategies.\n\nEach query option is identified by a keyword preceded by a plus sign (+). Some keywords set\nor reset an option. These may be preceded by the string no to negate the meaning of that key‐\nword. Other keywords assign values to options like the timeout interval. They have the form\n+keyword=value.\n", "subsections": [] }, "ANYWHERE OPTIONS": { "content": "", "subsections": [ { "name": "-f", "content": "process from the file filename. The file contains a number of queries, one per line.\nEach entry in the file should be organized in the same way they would be presented as\nqueries to mdig using the command-line interface.\n", "flag": "-f" }, { "name": "-h", "content": "tions, and exit.\n", "flag": "-h" }, { "name": "-v", "content": "", "flag": "-v" } ] }, "GLOBAL OPTIONS": { "content": "", "subsections": [ { "name": "-4", "content": "", "flag": "-4" }, { "name": "-6", "content": "", "flag": "-6" }, { "name": "-b address", "content": "This option sets the source IP address of the query to address. This must be a valid\naddress on one of the host's network interfaces or \"0.0.0.0\" or \"::\". An optional port\nmay be specified by appending \"#\"\n", "flag": "-b" }, { "name": "-m", "content": "", "flag": "-m" }, { "name": "-p port#", "content": "This option is used when a non-standard port number is to be queried. port# is the\nport number that mdig sends its queries to, instead of the standard DNS port number\n53. This option is used to test a name server that has been configured to listen for\nqueries on a non-standard port number.\n\nThe global query options are:\n", "flag": "-p" }, { "name": "+additional, +noadditional", "content": "This option displays [or does not display] the additional section of a reply. The de‐\nfault is to display it.\n" }, { "name": "+all, +noall", "content": "This option sets or clears all display flags.\n" }, { "name": "+answer, +noanswer", "content": "This option displays [or does not display] the answer section of a reply. The default\nis to display it.\n" }, { "name": "+authority, +noauthority", "content": "This option displays [or does not display] the authority section of a reply. The de‐\nfault is to display it.\n" }, { "name": "+besteffort, +nobesteffort", "content": "This option attempts to display [or does not display] the contents of messages which\nare malformed. The default is to not display malformed answers.\n\n+burst This option delays queries until the start of the next second.\n" }, { "name": "+cl, +nocl", "content": "This option displays [or does not display] the CLASS when printing the record.\n" }, { "name": "+comments, +nocomments", "content": "This option toggles the display of comment lines in the output. The default is to\nprint comments.\n" }, { "name": "+continue, +nocontinue", "content": "This option toggles continuation on errors (e.g. timeouts).\n" }, { "name": "+crypto, +nocrypto", "content": "This option toggles the display of cryptographic fields in DNSSEC records. The con‐\ntents of these fields are unnecessary to debug most DNSSEC validation failures and re‐\nmoving them makes it easier to see the common failures. The default is to display the\nfields. When omitted, they are replaced by the string \"[omitted]\"; in the DNSKEY case,\nthe key ID is displayed as the replacement, e.g., [ key id = value ].\n" }, { "name": "+dscp=value", "content": "This option formerly set the DSCP value used when sending a query. It is now obso‐\nlete, and has no effect.\n" }, { "name": "+multiline, +nomultiline", "content": "This option toggles printing of records, like the SOA records, in a verbose multi-line\nformat with human-readable comments. The default is to print each record on a single\nline, to facilitate machine parsing of the mdig output.\n" }, { "name": "+question, +noquestion", "content": "This option prints [or does not print] the question section of a query when an answer\nis returned. The default is to print the question section as a comment.\n" }, { "name": "+rrcomments, +norrcomments", "content": "This option toggles the display of per-record comments in the output (for example, hu‐\nman-readable key information about DNSKEY records). The default is not to print record\ncomments unless multiline mode is active.\n" }, { "name": "+short, +noshort", "content": "This option provides [or does not provide] a terse answer. The default is to print the\nanswer in a verbose form.\n" }, { "name": "+split=W", "content": "This option splits long hex- or base64-formatted fields in resource records into\nchunks of W characters (where W is rounded up to the nearest multiple of 4). +nosplit\nor +split=0 causes fields not to be split. The default is 56 characters, or 44 charac‐\nters when multiline mode is active.\n" }, { "name": "+tcp, +notcp", "content": "This option uses [or does not use] TCP when querying name servers. The default behav‐\nior is to use UDP.\n" }, { "name": "+ttlid, +nottlid", "content": "This option displays [or does not display] the TTL when printing the record.\n" }, { "name": "+ttlunits, +nottlunits", "content": "This option displays [or does not display] the TTL in friendly human-readable time\nunits of \"s\", \"m\", \"h\", \"d\", and \"w\", representing seconds, minutes, hours, days, and\nweeks. This implies +ttlid.\n" }, { "name": "+vc, +novc", "content": "This option uses [or does not use] TCP when querying name servers. This alternate syn‐\ntax to +tcp is provided for backwards compatibility. The vc stands for \"virtual cir‐\ncuit\".\n" } ] }, "LOCAL OPTIONS": { "content": "", "subsections": [ { "name": "-c class", "content": "This option sets the query class to class. It can be any valid query class which is\nsupported in BIND 9. The default query class is \"IN\".\n", "flag": "-c" }, { "name": "-t type", "content": "This option sets the query type to type. It can be any valid query type which is sup‐\nported in BIND 9. The default query type is \"A\", unless the -x option is supplied to\nindicate a reverse lookup with the \"PTR\" query type.\n", "flag": "-t" }, { "name": "-x addr", "content": "Reverse lookups - mapping addresses to names - are simplified by this option. addr is\nan IPv4 address in dotted-decimal notation, or a colon-delimited IPv6 address. mdig\nautomatically performs a lookup for a query name like 11.12.13.10.in-addr.arpa and\nsets the query type and class to PTR and IN respectively. By default, IPv6 addresses\nare looked up using nibble format under the IP6.ARPA domain.\n\nThe local query options are:\n", "flag": "-x" }, { "name": "+aaflag, +noaaflag", "content": "This is a synonym for +aaonly, +noaaonly.\n" }, { "name": "+aaonly, +noaaonly", "content": "This sets the aa flag in the query.\n" }, { "name": "+adflag, +noadflag", "content": "This sets [or does not set] the AD (authentic data) bit in the query. This requests\nthe server to return whether all of the answer and authority sections have all been\nvalidated as secure, according to the security policy of the server. AD=1 indicates\nthat all records have been validated as secure and the answer is not from a OPT-OUT\nrange. AD=0 indicates that some part of the answer was insecure or not validated.\nThis bit is set by default.\n" }, { "name": "+bufsize=B", "content": "This sets the UDP message buffer size advertised using EDNS0 to B bytes. The maximum\nand minimum sizes of this buffer are 65535 and 0 respectively. Values outside this\nrange are rounded up or down appropriately. Values other than zero cause a EDNS query\nto be sent.\n" }, { "name": "+cdflag, +nocdflag", "content": "This sets [or does not set] the CD (checking disabled) bit in the query. This requests\nthe server to not perform DNSSEC validation of responses.\n" }, { "name": "+cookie=####, +nocookie", "content": "This sends [or does not send] a COOKIE EDNS option, with an optional value. Replaying\na COOKIE from a previous response allows the server to identify a previous client. The\ndefault is +nocookie.\n" }, { "name": "+dnssec, +nodnssec", "content": "This requests that DNSSEC records be sent by setting the DNSSEC OK (DO) bit in the OPT\nrecord in the additional section of the query.\n" }, { "name": "+edns[=#], +noedns", "content": "This specifies [or does not specify] the EDNS version to query with. Valid values are\n0 to 255. Setting the EDNS version causes an EDNS query to be sent. +noedns clears\nthe remembered EDNS version. EDNS is set to 0 by default.\n" }, { "name": "+ednsflags[=#], +noednsflags", "content": "This sets the must-be-zero EDNS flag bits (Z bits) to the specified value. Decimal,\nhex, and octal encodings are accepted. Setting a named flag (e.g. DO) is silently ig‐\nnored. By default, no Z bits are set.\n" }, { "name": "+ednsopt[=code[:value]], +noednsopt", "content": "This specifies [or does not specify] an EDNS option with code point code and an op‐\ntional payload of value as a hexadecimal string. +noednsopt clears the EDNS options to\nbe sent.\n" }, { "name": "+expire, +noexpire", "content": "This toggles sending of an EDNS Expire option.\n" }, { "name": "+nsid, +nonsid", "content": "This toggles inclusion of an EDNS name server ID request when sending a query.\n" }, { "name": "+recurse, +norecurse", "content": "This toggles the setting of the RD (recursion desired) bit in the query. This bit is\nset by default, which means mdig normally sends recursive queries.\n" }, { "name": "+retry=T", "content": "This sets the number of times to retry UDP queries to server to T instead of the de‐\nfault, 2. Unlike +tries, this does not include the initial query.\n" }, { "name": "+subnet=addr[/prefix-length], +nosubnet", "content": "This sends [or does not send] an EDNS Client Subnet option with the specified IP ad‐\ndress or network prefix.\n" }, { "name": "mdig +subnet=0.0.0.0/0, or simply mdig +subnet=0", "content": "This sends an EDNS client-subnet option with an empty address and a source pre‐\nfix-length of zero, which signals a resolver that the client's address information\nmust not be used when resolving this query.\n" }, { "name": "+timeout=T", "content": "This sets the timeout for a query to T seconds. The default timeout is 5 seconds for\nUDP transport and 10 for TCP. An attempt to set T to less than 1 results in a query\ntimeout of 1 second being applied.\n" }, { "name": "+tries=T", "content": "This sets the number of times to try UDP queries to server to T instead of the de‐\nfault, 3. If T is less than or equal to zero, the number of tries is silently rounded\nup to 1.\n" }, { "name": "+udptimeout=T", "content": "This sets the timeout between UDP query retries to T.\n" }, { "name": "+unknownformat, +nounknownformat", "content": "This prints [or does not print] all RDATA in unknown RR-type presentation format (see\nRFC 3597). The default is to print RDATA for known types in the type's presentation\nformat.\n" }, { "name": "+yaml, +noyaml", "content": "This toggles printing of the responses in a detailed YAML format.\n" }, { "name": "+zflag, +nozflag", "content": "This sets [or does not set] the last unassigned DNS header flag in a DNS query. This\nflag is off by default.\n" } ] }, "SEE ALSO": { "content": "dig(1), RFC 1035.\n", "subsections": [] }, "AUTHOR": { "content": "Internet Systems Consortium\n", "subsections": [] }, "COPYRIGHT": { "content": "2026, Internet Systems Consortium\n\n\n\n\n9.18.39-0ubuntu0.22.04.4-Ubuntu 2025-08-13 MDIG(1)", "subsections": [] } }, "summary": "mdig - DNS pipelined lookup utility", "flags": [], "examples": [], "see_also": [ { "name": "dig", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/dig/1/json" } ] }