DIG(1) BIND9 DIG(1) NNAAMMEE dig - DNS lookup utility SSYYNNOOPPSSIISS ddiigg [@server] [--bb  _a_d_d_r_e_s_s] [--cc  _c_l_a_s_s] [--ff  _f_i_l_e_n_a_m_e] [--kk  _f_i_l_e_n_a_m_e] [--mm] [--pp  _p_o_r_t_#] [--qq  _n_a_m_e] [--tt  _t_y_p_e] [--vv] [--xx  _a_d_d_r] [--yy  _[_h_m_a_c_:_]_n_a_m_e_:_k_e_y] [--44] [--66] [name] [type] [class] [queryopt...] ddiigg [--hh] ddiigg [global-queryopt...] [query...] DDEESSCCRRIIPPTTIIOONN ddiigg (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 ddiigg to troubleshoot DNS problems because of its flexibility, ease of use and clarity of output. Other lookup tools tend to have less functionality than ddiigg. Although ddiigg 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 --hh option is given. Unlike earlier versions, the BIND 9 implementation of ddiigg allows multiple lookups to be issued from the command line. Unless it is told to query a specific name server, ddiigg will try each of the servers listed in /etc/resolv.conf. If no usable server addresses are found, ddiigg will send the query to the local host. When no command line arguments or options are given, ddiigg will perform an NS query for "." (the root). It is possible to set per-user defaults for ddiigg 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 --tt and --cc options to specify the type and class, use the --qq the specify the domain name, or use "IN." and "CH." when looking up these top level domains. SSIIMMPPLLEE UUSSAAGGEE A typical invocation of ddiigg looks like: dig @server name type where: sseerrvveerr 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 _s_e_r_v_e_r argument is a hostname, ddiigg resolves that name before querying that name server. If no _s_e_r_v_e_r argument is provided, ddiigg consults /etc/resolv.conf; if an address is found there, it queries the name server at that address. If either of the --44 or --66 options are in use, then only addresses for the corresponding transport will be tried. If no usable addresses are found, ddiigg will send the query to the local host. The reply from the name server that responds is displayed. nnaammee is the name of the resource record that is to be looked up. ttyyppee indicates what type of query is required — ANY, A, MX, SIG, etc. _t_y_p_e can be any valid query type. If no _t_y_p_e argument is supplied, ddiigg will perform a lookup for an A record. OOPPTTIIOONNSS -4 Use IPv4 only. -6 Use IPv6 only. -b _a_d_d_r_e_s_s_[_#_p_o_r_t_] Set the source IP address of the query. The _a_d_d_r_e_s_s 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 "#" -c _c_l_a_s_s Set the query class. The default _c_l_a_s_s is IN; other classes are HS for Hesiod records or CH for Chaosnet records. -f _f_i_l_e Batch mode: ddiigg reads a list of lookup requests to process from the given _f_i_l_e. Each line in the file should be organized in the same way they would be presented as queries to ddiigg using the command-line interface. -i 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 _k_e_y_f_i_l_e Sign queries using TSIG using a key read from the given file. Key files can be generated using ttssiigg--kkeeyyggeenn(8). When using TSIG authentication with ddiigg, 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 kkeeyy and sseerrvveerr statements in named.conf. -m Enable memory usage debugging. -p _p_o_r_t 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 _n_a_m_e The domain name to query. This is useful to distinguish the _n_a_m_e from other arguments. -t _t_y_p_e 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 --xx 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 _t_y_p_e 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. -v Print the version number and exit. -x _a_d_d_r Simplified reverse lookups, for mapping addresses to names. The _a_d_d_r is an IPv4 address in dotted-decimal notation, or a colon-delimited IPv6 address. When the --xx is used, there is no need to provide the _n_a_m_e, _c_l_a_s_s and _t_y_p_e arguments. ddiigg 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 --ii option). -y _[_h_m_a_c_:_]_k_e_y_n_a_m_e_:_s_e_c_r_e_t Sign queries using TSIG with the given authentication key. _k_e_y_n_a_m_e is the name of the key, and _s_e_c_r_e_t is the base64 encoded shared secret. _h_m_a_c is the name of the key algorithm; valid choices are hmac-md5, hmac-sha1, hmac-sha224, hmac-sha256, hmac-sha384, or hmac-sha512. If _h_m_a_c is not specified, the default is hmac-md5 or if MD5 was disabled hmac-sha256. NOTE: You should use the --kk option and avoid the --yy option, because with --yy the shared secret is supplied as a command line argument in clear text. This may be visible in the output from ppss(1) or in a history file maintained by the user's shell. mmaaccOOSS NNOOTTIICCEE The ddiigg command does not use the host name and address resolution or the DNS query routing mechanisms used by other processes running on macOS. The results of name or address queries printed by ddiigg may differ from those found by other processes that use the macOS native name and address resolution mechanisms. The results of DNS queries may also differ from queries that use the macOS DNS routing library. QQUUEERRYY OOPPTTIIOONNSS ddiigg 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 ++kkeeyywwoorrdd==vvaalluuee. Keywords may be abbreviated, provided the abbreviation is unambiguous; for example, +cd is equivalent to +cdflag. The query options are: ++[[nnoo]]aaaaffllaagg A synonym for _+_[_n_o_]_a_a_o_n_l_y. ++[[nnoo]]aaaaoonnllyy Sets the "aa" flag in the query. ++[[nnoo]]aaddddiittiioonnaall Display [do not display] the additional section of a reply. The default is to display it. ++[[nnoo]]aaddffllaagg 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. ++[[nnoo]]aallll Set or clear all display flags. ++[[nnoo]]aannsswweerr Display [do not display] the answer section of a reply. The default is to display it. ++[[nnoo]]aauutthhoorriittyy Display [do not display] the authority section of a reply. The default is to display it. ++[[nnoo]]bbeesstteeffffoorrtt Attempt to display the contents of messages which are malformed. The default is to not display malformed answers. ++bbuuffssiizzee==BB 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. ++[[nnoo]]ccddffllaagg Set [do not set] the CD (checking disabled) bit in the query. This requests the server to not perform DNSSEC validation of responses. ++[[nnoo]]ccllaassss Display [do not display] the CLASS when printing the record. ++[[nnoo]]ccmmdd Toggles the printing of the initial comment in the output identifying the version of ddiigg and the query options that have been applied. This comment is printed by default. ++[[nnoo]]ccoommmmeennttss Toggle the display of comment lines in the output. The default is to print comments. ++[[nnoo]]ccooookkiiee[[==########]] Send an COOKIE EDNS option, containing an optional _v_a_l_u_e. Replaying a COOKIE from a previous response will allow the server to identify a previous client. The default is ++nnooccooookkiiee. ++ccooookkiiee is automatically set when +trace is in use, to better emulate the default queries from a nameserver. This option was formerly called ++[[nnoo]]ssiitt (Server Identity Token). In BIND 9.10.0 through BIND 9.10.2, it sent the experimental option code 65001. This was changed to option code 10 in BIND 9.10.3 when the DNS COOKIE option was allocated. The ++[[nnoo]]ssiitt is now deprecated, but has been retained as a synonym for ++[[nnoo]]ccooookkiiee for backward compatibility within the BIND 9.10 branch. ++[[nnoo]]ccrryyppttoo 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 ]". ++[[nnoo]]ddeeffnnaammee Deprecated, treated as a synonym for _+_[_n_o_]_s_e_a_r_c_h ++[[nnoo]]ddnnsssseecc Requests DNSSEC records be sent by setting the DNSSEC OK bit (DO) in the OPT record in the additional section of the query. ++ddoommaaiinn==ssoommeennaammee Set the search list to contain the single domain _s_o_m_e_n_a_m_e, as if specified in a ddoommaaiinn directive in /etc/resolv.conf, and enable search list processing as if the _+_s_e_a_r_c_h option were given. ++[[nnoo]]eeddnnss[[==##]] 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. ++nnooeeddnnss clears the remembered EDNS version. EDNS is set to 0 by default. ++[[nnoo]]eeddnnssffllaaggss[[==##]] 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. ++[[nnoo]]eeddnnssnneeggoottiiaattiioonn Enable / disable EDNS version negotiation. By default EDNS version negotiation is enabled. ++[[nnoo]]eeddnnssoopptt[[==ccooddee[[::vvaalluuee]]]] Specify EDNS option with code point ccooddee and optionally payload of vvaalluuee as a hexadecimal string. ccooddee can be either an EDNS option name (for example, NSID or ECS), or an arbitrary numeric value. ++nnooeeddnnssoopptt clears the EDNS options to be sent. ++[[nnoo]]eexxppiirree Send an EDNS Expire option. ++[[nnoo]]ffaaiill 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. ++[[nnoo]]iiddeennttiiffyy Show [or do not show] the IP address and port number that supplied the answer when the _+_s_h_o_r_t 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. ++[[nnoo]]iiddnnoouutt 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. ++[[nnoo]]iiggnnoorree Ignore truncation in UDP responses instead of retrying with TCP. By default, TCP retries are performed. ++[[nnoo]]kkeeeeppooppeenn Keep the TCP socket open between queries and reuse it rather than creating a new TCP socket for each lookup. The default is ++nnookkeeeeppooppeenn. ++[[nnoo]]mmuullttiilliinnee 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 ddiigg output. ++nnddoottss==DD Set the number of dots that have to appear in _n_a_m_e 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 sseeaarrcchh or ddoommaaiinn directive in /etc/resolv.conf if ++sseeaarrcchh is set. ++[[nnoo]]nnssiidd Include an EDNS name server ID request when sending a query. ++[[nnoo]]nnsssseeaarrcchh When this option is set, ddiigg 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. ++[[nnoo]]oonneessooaa Print only one (starting) SOA record when performing an AXFR. The default is to print both the starting and ending SOA records. ++[[nnoo]]ooppccooddee==vvaalluuee Set [restore] the DNS message opcode to the specified value. The default value is QUERY (0). ++[[nnoo]]qqrr Print [do not print] the query as it is sent. By default, the query is not printed. ++[[nnoo]]qquueessttiioonn 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. ++[[nnoo]]rrddffllaagg A synonym for _+_[_n_o_]_r_e_c_u_r_s_e. ++[[nnoo]]rreeccuurrssee Toggle the setting of the RD (recursion desired) bit in the query. This bit is set by default, which means ddiigg normally sends recursive queries. Recursion is automatically disabled when the _+_n_s_s_e_a_r_c_h or _+_t_r_a_c_e query options are used. ++rreettrryy==TT Sets the number of times to retry UDP queries to server to _T instead of the default, 2. Unlike _+_t_r_i_e_s, this does not include the initial query. ++[[nnoo]]rrrrccoommmmeennttss 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. ++[[nnoo]]sseeaarrcchh 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 _+_n_d_o_t_s determines if the name will be treated as relative or not and hence whether a search is eventually performed or not. ++[[nnoo]]sshhoorrtt Provide a terse answer. The default is to print the answer in a verbose form. ++[[nnoo]]sshhoowwsseeaarrcchh Perform [do not perform] a search showing intermediate results. ++[[nnoo]]ssiiggcchhaassee Chase DNSSEC signature chains. Requires dig be compiled with -DDIG_SIGCHASE. This feature is deprecated. Use ddeellvv instead. ++[[nnoo]]ssiitt[[==########]] This option is a synonym for ++[[nnoo]]ccooookkiiee. The ++[[nnoo]]ssiitt is deprecated. ++sspplliitt==WW 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). _+_n_o_s_p_l_i_t or _+_s_p_l_i_t_=_0 causes fields not to be split at all. The default is 56 characters, or 44 characters when multiline mode is active. ++[[nnoo]]ssttaattss 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. ++[[nnoo]]ssuubbnneett==aaddddrr[[//pprreeffiixx--lleennggtthh]] Send (don't send) an EDNS Client Subnet option with the specified IP address or network prefix. ddiigg ++ssuubbnneett==00..00..00..00//00, or simply ddiigg ++ssuubbnneett==00 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 _n_o_t be used when resolving this query. ++[[nnoo]]ttccpp 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. ++ttiimmee==TT 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. ++[[nnoo]]ttooppddoowwnn When chasing DNSSEC signature chains perform a top-down validation. Requires dig be compiled with -DDIG_SIGCHASE. This feature is deprecated. Use ddeellvv instead. ++[[nnoo]]ttrraaccee 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, ddiigg 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. ++ddnnsssseecc is also set when +trace is set to better emulate the default queries from a nameserver. ++ttrriieess==TT 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. ++ttrruusstteedd--kkeeyy==######## Specifies a file containing trusted keys to be used with ++ssiiggcchhaassee. Each DNSKEY record must be on its own line. If not specified, ddiigg 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 ddeellvv instead. ++[[nnoo]]ttttlliidd Display [do not display] the TTL when printing the record. ++[[nnoo]]vvcc Use [do not use] TCP when querying name servers. This alternate syntax to _+_[_n_o_]_t_c_p is provided for backwards compatibility. The "vc" stands for "virtual circuit". MMUULLTTIIPPLLEE QQUUEERRIIEESS The BIND 9 implementation of ddiigg supports specifying multiple queries on the command line (in addition to supporting the --ff batch file option). Each of those queries can be supplied with its own set of flags, options and query options. In this case, each _q_u_e_r_y 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 ++[[nnoo]]ccmmdd 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 ddiigg 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 _+_q_r is applied, so that ddiigg shows the initial query it made for each lookup. The final query has a local query option of _+_n_o_q_r which means that ddiigg will not print the initial query when it looks up the NS records for isc.org. IIDDNN SSUUPPPPOORRTT If ddiigg has been built with IDN (internationalized domain name) support, it can accept and display non-ASCII domain names. ddiigg 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 IIDDNN__DDIISSAABBLLEE environment variable. The IDN support is disabled if the variable is set when ddiigg runs. FFIILLEESS /etc/resolv.conf ${HOME}/.digrc SSEEEE AALLSSOO ddeellvv(1), hhoosstt(1), nnaammeedd(8), ddnnsssseecc--kkeeyyggeenn(8), RFC1035. BBUUGGSS There are probably too many query options. AAUUTTHHOORR IInntteerrnneett SSyysstteemmss CCoonnssoorrttiiuumm,, IInncc.. CCOOPPYYRRIIGGHHTT Copyright © 2004-2011, 2013-2017 Internet Systems Consortium, Inc. ("ISC") Copyright © 2000-2003 Internet Software Consortium. ISC 2018-05-25 DIG(1)