.\" $Id: dig.1,v 8.3 1998/03/21 01:01:23 halley Exp $ .\" .\" ++Copyright++ 1993 .\" - .\" Copyright (c) 1993 .\" The Regents of the University of California. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by the University of .\" California, Berkeley and its contributors. .\" 4. 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DISCLAIMS ALL .\" WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES .\" OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT .\" CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL .\" DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR .\" PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS .\" ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS .\" SOFTWARE. .\" - .\" --Copyright-- .\" .\" Distributed with 'dig' version 2.0 from University of Southern .\" California Information Sciences Institute (USC-ISI). .\" .\" dig.1 2.0 (USC-ISI) 8/30/90 .\" .Dd August 30, 1990 .Dt DIG @CMD_EXT_U@ .Os BSD 4 .Sh NAME .Nm dig .Nd send domain name query packets to name servers .Sh SYNOPSIS .Nm dig .Op Ic @ Ns Ar server .Ar domain .Op Aq Ar query-type .Op Aq Ar query-class .Op Ic + Ns Aq Ar query-option .Op Fl Aq Ar dig-option .Op Ar %comment .Sh DESCRIPTION .Ic Dig (domain information groper) is a flexible command line tool which can be used to gather information from the Domain Name System servers. .Ic Dig has two modes: simple interactive mode for a single query, and batch mode which executes a query for each in a list of several query lines. All query options are accessible from the command line. .Pp The usual simple use of .Ic dig will take the form: .Pp .Bd -ragged -offset indent-two .Ic dig @ Ns Ar server domain query-type query-class .Ed .Pp where: .Bl -tag -width Fl .It Ar server may be either a domain name or a dot-notation Internet address. If this optional field is omitted, .Ic dig will attempt to use the default name server for your machine. .sp 1 .Em Note: If a domain name is specified, this will be resolved using the domain name system resolver (i.e., BIND). If your system does not support DNS, you may .Em have to specify a dot-notation address. Alternatively, if there is a server at your disposal somewhere, all that is required is that .Pa /etc/resolv.conf be present and indicate where the default name servers reside, so that .Ar server itself can be resolved. See .Xr resolver @FORMAT_EXT@ for information on .Pa /etc/resolv.conf . .Sy WARNING: Changing .Pa /etc/resolv.conf will affect both the standard resolver library and .Pq potentially several programs which use it. As an option, the user may set the environment variable .Ev LOCALRES to name a file which is to be used instead of .Pa /etc/resolv.conf .Po Ns Ev LOCALRES is specific to the .Ic dig resolver and is not referenced by the standard resolver .Pc . If the .Ev LOCALRES variable is not set or the specified file is not readable, then .Pa /etc/resolv.conf will be used. .It Ar domain is the domain name for which you are requesting information. See the .Fl x option (documented in the .Sx OTHER OPTIONS subsection of this section) for convenient way to specify inverse address query. .It Ar query-type is the type of information (DNS query type) that you are requesting. If omitted, the default is .Dq Ar a .Pq Dv T_A = Ar address . The following types are recognized: .Pp .Bl -hang -width "hinfo T_HINFO " -compact .It Ar a\ \ \ \ \ \ Dv T_A network address .It Ar any\ \ \ \ Dv T_ANY all/any information about specified domain .It Ar mx\ \ \ \ \ Dv T_MX mail exchanger for the domain .It Ar ns\ \ \ \ \ Dv T_NS name servers .It Ar soa\ \ \ \ Dv T_SOA zone of authority record .It Ar hinfo\ \ Dv T_HINFO host information .It Ar axfr\ \ \ Dv T_AXFR zone transfer (must ask an authoritative server) .It Ar txt\ \ \ \ Dv T_TXT arbitrary number of strings .El .Pp (See RFC 1035 for the complete list.) .It Ar query-class is the network class requested in the query. If omitted, the default is .Dq Ar in .Pq Dv C_IN = Ar Internet . The following classes are recognized: .Pp .Bl -tag -width "hinfo T_HINFO " -compact .It Ar in\ \ \ \ \ Dv C_IN Internet class domain .It Ar any\ \ \ \ Dv C_ANY all/any class information .El .Pp (See RFC 1035 for the complete list.) .Pp .Em Note: .Dq Ar Any can be used to specify a .Em class and/or a .Em type of query. .Ic Dig will parse the first occurrence of .Dq Ar any to mean .Ar query-type = Dv T_ANY . To specify .Ar query-class = Dv C_ANY , you must either specify .Dq any twice, or set .Ar query-class using the .Fl c option (see below). .El .Ss OTHER OPTIONS .Bl -tag -width Fl .It % Ns Ar ignored-comment .Dq % is used to included an argument that is simply not parsed. This may be useful if running .Ic dig in batch mode. Instead of resolving every .Ar @server-domain-name in a list of queries, you can avoid the overhead of doing so, and still have the domain name on the command line as a reference. Example: .Pp .Bd -ragged -offset indent-two .Ic dig @128.9.0.32 %venera.isi.edu mx isi.edu .Ed .Pp .It Fl Aq Ar dig option .Dq Fl is used to specify an option which affects the operation of .Ic dig . The following options are currently available (although not guaranteed to be useful): .Bl -tag -width Fl .It Fl x Ar dot-notation-address Convenient form to specify inverse address mapping. Instead of .Dq Ic dig 32.0.9.128.in-addr.arpa , one can simply .Dq Ic dig -x 128.9.0.32 . .It Fl f Ar file File for .Ic dig batch mode. The file contains a list of query specifications ( .Ns Ic dig command lines) which are to be executed successively. Lines beginning with .Sq \&; , .Sq # , or .Sq \en are ignored. Other options may still appear on command line, and will be in effect for each batch query. .It Fl T Ar time Time in seconds between start of successive queries when running in batch mode. Can be used to keep two or more batch .Ic dig commands running roughly in sync. Default is zero. .It Fl p Ar port Port number. Query a name server listening to a non-standard port number. Default is 53. .It Fl P Ns Bq Ar ping-string After query returns, execute a .Xr ping @SYS_OPS_EXT@ command for response time comparison. This rather unelegantly makes a call to the shell. The last three lines of statistics is printed for the command: .Pp .Bd -ragged -offset indent-two .Ic ping Fl s server_name 56 3 .Ed .Pp If the optional .Dq Ar ping_string is present, it replaces .Dq Ic ping Fl s in the shell command. .It Fl t Ar query-type Specify type of query. May specify either an integer value to be included in the type field or use the abbreviated mnemonic as discussed above (i.e., .Ar mx = Dv T_MX ) . .It Fl c Ar query-class Specify class of query. May specify either an integer value to be included in the class field or use the abbreviated mnemonic as discussed above (i.e., in = C_IN). .It Fl envsav This flag specifies that the .Ic dig environment (defaults, print options, etc.), after all of the arguments are parsed, should be saved to a file to become the default environment. This is useful if you do not like the standard set of defaults and do not desire to include a large number of options each time .Ic dig is used. The environment consists of resolver state variable flags, timeout, and retries as well as the flags detailing .Ic dig output (see below). If the shell environment variable .Ev LOCALDEF is set to the name of a file, this is where the default .Ic dig environment is saved. If not, the file .Dq Pa DiG.env is created in the current working directory. .Pp .Em Note: .Ev LOCALDEF is specific to the .Ic dig resolver, and will not affect operation of the standard resolver library. .Pp Each time .Ic dig is executed, it looks for .Dq Pa ./DiG.env or the file specified by the shell environment variable .Ev LOCALDEF . If such file exists and is readable, then the environment is restored from this file before any arguments are parsed. .It Fl envset This flag only affects batch query runs. When .Dq Fl envset is specified on a line in a .Ic dig batch file, the .Ic dig environment after the arguments are parsed becomes the default environment for the duration of the batch file, or until the next line which specifies .Dq Fl envset . .It Xo .Fl Op Cm no .Ns Cm stick .Xc This flag only affects batch query runs. It specifies that the .Ic dig environment (as read initially or set by .Dq Fl envset switch) is to be restored before each query (line) in a .Ic dig batch file. The default .Dq Fl nostick means that the .Ic dig environment does not stick, hence options specified on a single line in a .Ic dig batch file will remain in effect for subsequent lines (i.e. they are not restored to the .Dq sticky default). .El .It Ic + Ns Aq Ar query-option .Dq + is used to specify an option to be changed in the query packet or to change .Ic dig output specifics. Many of these are the same parameters accepted by .Xr nslookup @SYS_OPS_EXT@ . If an option requires a parameter, the form is as follows: .Pp .Bd -ragged -offset indent-two .Ic + .Ns Ar keyword .Ns Op = Ns Ar value .Ed .Pp Most keywords can be abbreviated. Parsing of the .Dq + options is very simplistic \(em a value must not be separated from its keyword by white space. The following keywords are currently available: .Pp Keyword Abbrev. Meaning [default] .Pp .Bl -tag -width "[no]primary (ret) " -compact .It Xo .Op Cm no .Ns Cm debug\ \ \ \ .Pq Cm deb .Xc turn on/off debugging mode .Bq Cm deb .It Xo .Op Cm no .Ns Cm d2\ \ \ \ \ \ \ \ \ \ .Xc turn on/off extra debugging mode .Bq Cm nod2 .It Xo .Op Cm no .Ns Cm recurse\ \ .Pq Cm rec .Xc use/don't use recursive lookup .Bq Cm rec .It Xo .Cm retry= Ns Ar # .Cm \ \ \ \ \ .Pq Cm ret .Xc set number of retries to # .Bq 4 .It Xo .Cm time= Ns Ar # .Cm \ \ \ \ \ \ .Pq Cm ti .Xc set timeout length to # seconds .Bq 4 .It Xo .Op Cm no .Ns Cm ko .Xc keep open option (implies vc) .Bq Cm noko .It Xo .Op Cm no .Ns Cm vc .Xc use/don't use virtual circuit .Bq Cm novc .It Xo .Op Cm no .Ns Cm defname\ \ .Pq Cm def .Xc use/don't use default domain name .Bq Cm def .It Xo .Op Cm no .Ns Cm search\ \ \ .Pq Cm sea .Xc use/don't use domain search list .Bq Cm sea .It Xo .Cm domain= Ns Ar NAME\ \ .Pq Cm do .Xc set default domain name to .Ar NAME .It Xo .Op Cm no .Ns Cm ignore\ \ \ .Pq Cm i .Xc ignore/don't ignore trunc. errors .Bq Cm noi .It Xo .Op Cm no .Ns Cm primary\ \ .Pq Cm pr .Xc use/don't use primary server .Bq Cm nopr .It Xo .Op Cm no .Ns Cm aaonly\ \ \ .Pq Cm aa .Xc authoritative query only flag .Bq Cm noaa .It Xo .Op Cm no .Ns Cm cmd .Xc echo parsed arguments .Bq Cm cmd .It Xo .Op Cm no .Ns Cm stats\ \ \ \ .Pq Cm st .Xc print query statistics .Bq Cm st .It Xo .Op Cm no .Ns Cm Header\ \ \ .Pq Cm H .Xc print basic header .Bq Cm H .It Xo .Op Cm no .Ns Cm header\ \ \ .Pq Cm he .Xc print header flags .Bq Cm he .It Xo .Op Cm no .Ns Cm ttlid\ \ \ \ .Pq Cm tt .Xc print TTLs .Bq Cm tt .It Xo .Op Cm no .Ns Cm cl .Xc print class info .Bq Cm nocl .It Xo .Op Cm no .Ns Cm qr .Xc print outgoing query .Bq Cm noqr .It Xo .Op Cm no .Ns Cm reply\ \ \ \ .Pq Cm rep .Xc print reply .Bq Cm rep .It Xo .Op Cm no .Ns Cm ques\ \ \ \ \ .Pq Cm qu .Xc print question section .Bq Cm qu .It Xo .Op Cm no .Ns Cm answer\ \ \ .Pq Cm an .Xc print answer section .Bq Cm an .It Xo .Op Cm no .Ns Cm author\ \ \ .Pq Cm au .Xc print authoritative section .Bq Cm au .It Xo .Op Cm no .Ns Cm addit\ \ \ \ .Pq Cm ad .Xc print additional section .Bq Cm ad .It Cm pfdef set to default print flags .It Cm pfmin set to minimal default print flags .It Cm pfset= Ns Ar # set print flags to # (# can be hex/octal/decimal) .It Cm pfand= Ns Ar # bitwise and print flags with # .It Cm pfor= Ns Ar # bitwise or print flags with # .El .Pp The .Cm retry and .Cm time options affect the retransmission strategy used by the resolver library when sending datagram queries. The algorithm is as follows: .Pp .Bd -literal -offset indent for i = 0 to retry - 1 for j = 1 to num_servers send_query wait((time * (2**i)) / num_servers) end end .Ed .Pp (Note: .Ic dig always uses a value of 1 for .Dq Li num_servers . ) .El .Ss DETAILS .Ic Dig once required a slightly modified version of the BIND .Xr resolver @LIB_NETWORK_EXT@ library. As of BIND 4.9, BIND's resolver has been augmented to work properly with .Ic dig . Essentially, .Ic dig is a straight-forward (albeit not pretty) effort of parsing arguments and setting appropriate parameters. .Ic Dig uses .Xr resolver @LIB_NETWORK_EXT@ routines .Fn res_init , .Fn res_mkquery , .Fn res_send as well as accessing the .Ft _res structure. .Sh ENVIRONMENT .Bl -tag -width "LOCALRES " -compact .It Ev LOCALRES file to use in place of Pa /etc/resolv.conf .It Ev LOCALDEF default environment file .El .Pp See also the explanation of the .Fl envsav , .Fl envset , and .Xo .Fl Op Cm no .Ns Cm stick .Xc options, above. .Sh FILES .Bl -tag -width "/etc/resolv.conf " -compact .It Pa /etc/resolv.conf initial domain name and name server addresses .It Pa \./DiG.env default save file for default options .El .Sh SEE ALSO .Xr @INDOT@named @SYS_OPS_EXT@ , .Xr resolver @LIB_NETWORK_EXT@ , .Xr resolver @FORMAT_EXT@ , .Xr nslookup @SYS_OPS_EXT@ . .Sh STANDARDS RFC 1035. .Sh AUTHOR Steve Hotz hotz@isi.edu .Sh ACKNOWLEDGMENTS .Ic Dig uses functions from .Xr nslookup @SYS_OPS_EXT@ authored by Andrew Cherenson. .Sh BUGS .Ic Dig has a serious case of "creeping featurism" -- the result of considering several potential uses during it's development. It would probably benefit from a rigorous diet. Similarly, the print flags and granularity of the items they specify make evident their rather ad hoc genesis. .Pp .Ic Dig does not consistently exit nicely (with appropriate status) when a problem occurs somewhere in the resolver .Po Sy NOTE: most of the common exit cases are handled .Pc . This is particularly annoying when running in batch mode. If it exits abnormally (and is not caught), the entire batch aborts; when such an event is trapped, .Ic dig simply continues with the next query.