dig(1M) 						  System Administration Commands						   dig(1M)

NAME

       dig - DNS lookup utility

SYNOPSIS

       dig  [@server]  [-b  address]  [-c  class]  [-f	filename] [-k filename] [-p port#] [-t type] [-x addr] [-y name:key] [name] [type] [class]
       [queryopt...]

       dig -h

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

DESCRIPTION

       The dig utility (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 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 specified. Unlike earlier versions, the BIND9
       implementation of dig allows multiple lookups to be issued from the command line.

       Unless it is told to query a specific name server, dig tries each of the servers listed in /etc/resolv.conf.

       When no command line arguments or options are given, dig performs an NS query for "." (the root).

       It is possible to set per user defaults for dig with ${HOME}/.digrc. This file is read and any options in it are applied before the command
       line arguments.

       The following is a typical invocation of dig:

       dig @server name type

       where:

       server	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 and queries the name servers listed there. The reply from
		the name server that responds is displayed.

       name	The name of the resource record that is to be looked up.

       type	Indicates what type of query is required (ANY, A, MX, SIG, among others.) type can be any valid query type. If no type argument is
		supplied, dig performs a lookup for an A record.

OPTIONS

       The following options are supported:

       -b address      Set the source IP address of the query to address. This must be a valid address on one of the host's network interfaces.

       -c class        Override the default query class (IN for internet). The class argument is any valid class, such as HS for Hesiod records or
		       CH for CHAOSNET records.

       -f filename     Operate in batch mode by reading a list of lookup requests to process from the file filename. The file contains a number of
		       queries, one per line. Each entry in the file should be organised in the same way they would be presented as queries to dig
		       using the command-line interface.

       -h	       Print a brief summary of command-line arguments and options.

       -k filename     Specify a transaction signature (TSIG) key file to sign the DNS queries sent by dig and their responses using TSIGs.

       -p port#        Query a non-standard port number. The port# argument is the port number that dig sends its queries instead of the  standard
		       DNS  port  number 53. This option tests a name server that has been configured to listen for queries on a non-standard port
		       number.

       -t type	       Set the query type to type, which can be any valid query type supported in BIND9. The default query type "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, type is set 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.

       -x addr	       Simplify reverse lookups (mapping addresses to names ). The addr argument is an IPv4 address in dotted-decimal notation, or
		       a colon-delimited IPv6 address. When this option is used, there is no need to provide the name, class and  type	arguments.
		       The  dig utility automatically performs a lookup for a name like 11.12.13.10.in-addr.arpa and sets the query type and class
		       to PTR and IN, respectively. By default, IPv6 addresses are looked up using  the  IP6.ARPA  domain  and	binary	labels	as
		       defined	in RFC 2874. Specify the -n (nibble) option to use the older RFC 1886 method using the IP6.INT domain and "nibble"
		       labels .

       -y name:key     Specify a transaction signature (TSIG) key on the command line. The name argument is the name of the TSIG key and  the  key
		       argument  is  the actual key. The key is a base-64 encoded string, typically generated by dnssec-keygen(1M). Caution should
		       be taken when using the -y option on multi-user systems, since the key can be visible in the output from ps(1)  or  in  the
		       shell's	history  file.	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(4).

QUERY OPTIONS

       The dig utility 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. The query options are:

       +[no]tcp 	       Use [do not use] TCP when querying name servers. The default behaviour is to use UDP unless an AXFR or  IXFR  query
			       is requested, in which case a TCP connection is used.

       +[no]vc		       Use  [do  not use] TCP when querying name servers. This alternate syntax to +[no]tcp is provided for backwards com-
			       patibility. The "vc" stands for "virtual circuit".

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

       +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.

       +[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.

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

       +[no]aaonly	       This option does nothing. It is provided for compatibility with old versions of dig where it set  an  unimplemented
			       resolver flag.

       +[no]adflag	       Set  [do  not  set]  the  AD (authentic data) bit in the query. The AD bit currently has a standard meaning only in
			       responses, not in queries, but the ability to set the bit in the query is provided for completeness.

       +[no]cdflag	       Set [do not set] the CD (checking disabled) bit in the query. This requests the server to not perform DNSSEC  vali-
			       dation of responses.

       +[no]recurse	       Toggle the setting of the RD (recursion desired) bit in the query. This bit is set by default, which means dig nor-
			       mally sends recursive queries. Recursion is automatically disabled when the +nssearch or +trace query  options  are
			       used.

       +[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]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 fol-
			       low referrals from the root servers, showing the answer from each server that was used to resolve the lookup.

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

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

       +[no]stats	       Toggle  the printing of statistics: when the query was made, the size of the reply and so on. The default behaviour
			       is to print the query statistics.

       +[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  ques-
			       tion section as a comment.

       +[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]additional	       Display [do not display] the additional section of a reply. The default is to display it.

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

       +time=T		       Sets  the  timeout  for a query to T seconds. The default time out is 5 seconds. An attempt to set T to less than 1
			       will result in a query timeout of 1 second being applied.

       +tries=T 	       Sets the number of times to retry UDP queries to server to T instead of the default, 3. If T is less than or  equal
			       to zero, the number of retries is silently rounded up to 1.

       +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.

       +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.

       +[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.

       +[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 behaviour.

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

       +[no]dnssec	       Request DNSSEC records be sent by setting the DNSSEC OK bit (DO) in the OPT record in the additional section of the
			       query.

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, global-queryopt, can be applied to all queries. 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.

FILES

       /etc/resolv.conf        Resolver configuration file

       ${HOME}/.digrc	       User-defined configuration file

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       |Availability		     |SUNWbind9 		   |
       |Interface Stability	     |External			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       dnssec-keygen(1M), host(1M), named(1M), attributes(5)

       RFC 1035

BUGS

       There are probably too many query options.

NOTES

       Source for BIND9 is available in the SUNWbind9S package.

SunOS 5.10							    15 Dec 2004 							   dig(1M)