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<refentry xmlns:db="http://docbook.org/ns/docbook" version="5.0" xml:id="man.dig">
<info>
<date>2014-02-19</date>
</info>
<refentryinfo>
<corpname>ISC</corpname>
<corpauthor>Internet Systems Consortium, Inc.</corpauthor>
</refentryinfo>
<refmeta>
<refentrytitle>dig</refentrytitle>
<manvolnum>1</manvolnum>
<refmiscinfo>BIND9</refmiscinfo>
</refmeta>
<refnamediv>
<refname>dig</refname>
<refpurpose>DNS lookup utility</refpurpose>
</refnamediv>
<docinfo>
<copyright>
<year>2000</year>
<year>2001</year>
<year>2002</year>
<year>2003</year>
<year>2004</year>
<year>2005</year>
<year>2006</year>
<year>2007</year>
<year>2008</year>
<year>2009</year>
<year>2010</year>
<year>2011</year>
<year>2013</year>
<year>2014</year>
<year>2015</year>
<year>2016</year>
<year>2017</year>
<year>2018</year>
<year>2019</year>
<year>2020</year>
<holder>Internet Systems Consortium, Inc. ("ISC")</holder>
</copyright>
</docinfo>
<refsynopsisdiv>
<cmdsynopsis sepchar=" ">
<command>dig</command>
<arg choice="opt" rep="norepeat">@server</arg>
<arg choice="opt" rep="norepeat"><option>-b <replaceable class="parameter">address</replaceable></option></arg>
<arg choice="opt" rep="norepeat"><option>-c <replaceable class="parameter">class</replaceable></option></arg>
<arg choice="opt" rep="norepeat"><option>-f <replaceable class="parameter">filename</replaceable></option></arg>
<arg choice="opt" rep="norepeat"><option>-k <replaceable class="parameter">filename</replaceable></option></arg>
<arg choice="opt" rep="norepeat"><option>-m</option></arg>
<arg choice="opt" rep="norepeat"><option>-p <replaceable class="parameter">port#</replaceable></option></arg>
<arg choice="opt" rep="norepeat"><option>-q <replaceable class="parameter">name</replaceable></option></arg>
<arg choice="opt" rep="norepeat"><option>-t <replaceable class="parameter">type</replaceable></option></arg>
<arg choice="opt" rep="norepeat"><option>-v</option></arg>
<arg choice="opt" rep="norepeat"><option>-x <replaceable class="parameter">addr</replaceable></option></arg>
<arg choice="opt" rep="norepeat"><option>-y <replaceable class="parameter"><optional>hmac:</optional>name:key</replaceable></option></arg>
<group choice="opt" rep="norepeat">
<arg choice="opt" rep="norepeat"><option>-4</option></arg>
<arg choice="opt" rep="norepeat"><option>-6</option></arg>
</group>
<arg choice="opt" rep="norepeat">name</arg>
<arg choice="opt" rep="norepeat">type</arg>
<arg choice="opt" rep="norepeat">class</arg>
<arg choice="opt" rep="repeat">queryopt</arg>
</cmdsynopsis>
<cmdsynopsis sepchar=" ">
<command>dig</command>
<arg choice="opt" rep="norepeat"><option>-h</option></arg>
</cmdsynopsis>
<cmdsynopsis sepchar=" ">
<command>dig</command>
<arg choice="opt" rep="repeat">global-queryopt</arg>
<arg choice="opt" rep="repeat">query</arg>
</cmdsynopsis>
</refsynopsisdiv>
<refsection><info><title>DESCRIPTION</title></info>
<para><command>dig</command> 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 <command>dig</command> to
troubleshoot DNS problems because of its flexibility, ease of use and
clarity of output. Other lookup tools tend to have less functionality
than <command>dig</command>.
</para>
<para>
Although <command>dig</command> 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> option is given.
Unlike earlier versions, the BIND 9 implementation of
<command>dig</command> allows multiple lookups to be issued
from the
command line.
</para>
<para>
Unless it is told to query a specific name server,
<command>dig</command> will try each of the servers listed in
<filename>/etc/resolv.conf</filename>. If no usable server addresses
are found, <command>dig</command> will send the query to the local
host.
</para>
<para>
When no command line arguments or options are given,
<command>dig</command> will perform an NS query for "." (the root).
</para>
<para>
It is possible to set per-user defaults for <command>dig</command> via
<filename>${HOME}/.digrc</filename>. This file is read and any
options in it are applied before the command line arguments.
The <option>-r</option> option disables this feature, for
scripts that need predictable behaviour.
</para>
<para>
The IN and CH class names overlap with the IN and CH top level
domain names. Either use the <option>-t</option> and
<option>-c</option> options to specify the type and class,
use the <option>-q</option> the specify the domain name, or
use "IN." and "CH." when looking up these top level domains.
</para>
</refsection>
<refsection><info><title>SIMPLE USAGE</title></info>
<para>
A typical invocation of <command>dig</command> looks like:
<programlisting> dig @server name type </programlisting>
where:
<variablelist>
<varlistentry>
<term><constant>server</constant></term>
<listitem>
<para>
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
<parameter>server</parameter> argument is a hostname,
<command>dig</command> resolves that name before querying
that name server.
</para>
<para>
If no <parameter>server</parameter> argument is
provided, <command>dig</command> consults
<filename>/etc/resolv.conf</filename>; if an
address is found there, it queries the name server at
that address. If either of the <option>-4</option> or
<option>-6</option> options are in use, then
only addresses for the corresponding transport
will be tried. If no usable addresses are found,
<command>dig</command> will send the query to the
local host. The reply from the name server that
responds is displayed.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><constant>name</constant></term>
<listitem>
<para>
is the name of the resource record that is to be looked up.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><constant>type</constant></term>
<listitem>
<para>
indicates what type of query is required —
ANY, A, MX, SIG, etc.
<parameter>type</parameter> can be any valid query
type. If no
<parameter>type</parameter> argument is supplied,
<command>dig</command> will perform a lookup for an
A record.
</para>
</listitem>
</varlistentry>
</variablelist>
</para>
</refsection>
<refsection><info><title>OPTIONS</title></info>
<variablelist>
<varlistentry>
<term>-4</term>
<listitem>
<para>
Use IPv4 only.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>-6</term>
<listitem>
<para>
Use IPv6 only.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>-b <replaceable class="parameter">address<optional>#port</optional></replaceable></term>
<listitem>
<para>
Set the source IP address of the query.
The <parameter>address</parameter> 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>"
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>-c <replaceable class="parameter">class</replaceable></term>
<listitem>
<para>
Set the query class. The
default <parameter>class</parameter> is IN; other classes
are HS for Hesiod records or CH for Chaosnet records.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>-f <replaceable class="parameter">file</replaceable></term>
<listitem>
<para>
Batch mode: <command>dig</command> reads a list of lookup
requests to process from the
given <parameter>file</parameter>. Each line in the file
should be organized in the same way they would be
presented as queries to
<command>dig</command> using the command-line interface.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>-i</term>
<listitem>
<para>
Do reverse IPv6 lookups using the obsolete RFC 1886 IP6.INT
domain, which is no longer in use. Obsolete bit string
label queries (RFC 2874) are not attempted.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>-k <replaceable class="parameter">keyfile</replaceable></term>
<listitem>
<para>
Sign queries using TSIG using a key read from the given file.
Key files can be generated using
<citerefentry>
<refentrytitle>tsig-keygen</refentrytitle><manvolnum>8</manvolnum>
</citerefentry>.
When using TSIG authentication with <command>dig</command>,
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 <command>key</command>
and <command>server</command> statements in
<filename>named.conf</filename>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>-m</term>
<listitem>
<para>
Enable memory usage debugging.
<!-- It enables ISC_MEM_DEBUGTRACE and ISC_MEM_DEBUGRECORD
documented in include/isc/mem.h -->
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>-p <replaceable class="parameter">port</replaceable></term>
<listitem>
<para>
Send the query to a non-standard port on the server,
instead of the default 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.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>-q <replaceable class="parameter">name</replaceable></term>
<listitem>
<para>
The domain name to query. This is useful to distinguish
the <parameter>name</parameter> from other arguments.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>-r</term>
<listitem>
<para>
Do not read options from <filename>${HOME}/.digrc</filename>.
This is useful for scripts that need predictable behaviour.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>-t <replaceable class="parameter">type</replaceable></term>
<listitem>
<para>
The resource record type to query. It 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>
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
<parameter>type</parameter> to <literal>ixfr=N</literal>.
The incremental zone transfer will contain the changes
made to the zone since the serial number in the zone's SOA
record was
<parameter>N</parameter>.
</para>
<para>
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 will be displayed as
described in RFC 3597.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>-u</term>
<listitem>
<para>
Print query times in microseconds instead of milliseconds.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>-v</term>
<listitem>
<para>
Print the version number and exit.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>-x <replaceable class="parameter">addr</replaceable></term>
<listitem>
<para>
Simplified reverse lookups, for mapping addresses to
names. The <parameter>addr</parameter> 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 <parameter>name</parameter>, <parameter>class</parameter>
and <parameter>type</parameter>
arguments. <command>dig</command> automatically performs a
lookup for a name like
<literal>94.2.0.192.in-addr.arpa</literal> 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 <option>-i</option>
option).
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>-y <replaceable class="parameter"><optional>hmac:</optional>keyname:secret</replaceable></term>
<listitem>
<para>
Sign queries using TSIG with the given authentication key.
<parameter>keyname</parameter> is the name of the key, and
<parameter>secret</parameter> is the base64 encoded shared secret.
<parameter>hmac</parameter> is the name of the key algorithm;
valid choices are <literal>hmac-md5</literal>,
<literal>hmac-sha1</literal>, <literal>hmac-sha224</literal>,
<literal>hmac-sha256</literal>, <literal>hmac-sha384</literal>, or
<literal>hmac-sha512</literal>. If <parameter>hmac</parameter>
is not specified, the default is <literal>hmac-md5</literal>
or if MD5 was disabled <literal>hmac-sha256</literal>.
</para>
<para>
NOTE: You should use the <option>-k</option> option and
avoid the <option>-y</option> option, because
with <option>-y</option> the shared secret is supplied as
a command line argument in clear text. This may be visible
in the output from
<citerefentry>
<refentrytitle>ps</refentrytitle><manvolnum>1</manvolnum>
</citerefentry>
or in a history file maintained by the user's shell.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsection>
<refsection><info><title>QUERY OPTIONS</title></info>
<para><command>dig</command>
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.
</para>
<para>
Each query option is identified by a keyword preceded by a plus sign
(<literal>+</literal>). Some keywords set or reset an
option. These may be preceded
by the string <literal>no</literal> to negate the meaning of
that keyword. Other
keywords assign values to options like the timeout interval. They
have the form <option>+keyword=value</option>.
Keywords may be abbreviated, provided the abbreviation is
unambiguous; for example, <literal>+cd</literal> is equivalent
to <literal>+cdflag</literal>.
The query options are:
<variablelist>
<varlistentry>
<term><option>+[no]aaflag</option></term>
<listitem>
<para>
A synonym for <parameter>+[no]aaonly</parameter>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]aaonly</option></term>
<listitem>
<para>
Sets the "aa" flag in the query.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]additional</option></term>
<listitem>
<para>
Display [do not display] the additional section of a
reply. The default is to display it.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]adflag</option></term>
<listitem>
<para>
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.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]all</option></term>
<listitem>
<para>
Set or clear all display flags.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]answer</option></term>
<listitem>
<para>
Display [do not display] the answer section of a
reply. The default is to display it.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]authority</option></term>
<listitem>
<para>
Display [do not display] the authority section of a
reply. The default is to display it.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]badcookie</option></term>
<listitem>
<para>
Retry lookup with the new server cookie if a
BADCOOKIE response is received.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]besteffort</option></term>
<listitem>
<para>
Attempt to display the contents of messages which are
malformed. The default is to not display malformed
answers.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+bufsize=B</option></term>
<listitem>
<para>
Set the UDP message buffer size advertised using EDNS0
to <parameter>B</parameter> 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.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]cdflag</option></term>
<listitem>
<para>
Set [do not set] the CD (checking disabled) bit in
the query. This requests the server to not perform
DNSSEC validation of responses.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]class</option></term>
<listitem>
<para>
Display [do not display] the CLASS when printing the
record.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]cmd</option></term>
<listitem>
<para>
Toggles the printing of the initial comment in the
output, identifying the version of <command>dig</command>
and the query options that have been applied. This option
always has global effect; it cannot be set globally
and then overridden on a per-lookup basis. The default
is to print this comment.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]comments</option></term>
<listitem>
<para>
Toggles the display of some comment lines in the output,
containing information about the packet header and
OPT pseudosection, and the names of the response
section. The default is to print these comments.
</para>
<para>
Other types of comments in the output are not affected by
this option, but can be controlled using other command
line switches. These include <command>+[no]cmd</command>,
<command>+[no]question</command>,
<command>+[no]stats</command>, and
<command>+[no]rrcomments</command>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]cookie<optional>=####</optional></option></term>
<listitem>
<para>
Send a COOKIE EDNS option, with optional
value. Replaying a COOKIE from a previous response will
allow the server to identify a previous client. The
default is <option>+cookie</option>.
</para>
<para>
<command>+cookie</command> is also set when +trace
is set to better emulate the default queries from a
nameserver.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]crypto</option></term>
<listitem>
<para>
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 ]".
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]defname</option></term>
<listitem>
<para>
Deprecated, treated as a synonym for
<parameter>+[no]search</parameter>
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]dnssec</option></term>
<listitem>
<para>
Requests DNSSEC records be sent by setting the DNSSEC
OK bit (DO) in the OPT record in the additional section
of the query.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+domain=somename</option></term>
<listitem>
<para>
Set the search list to contain the single domain
<parameter>somename</parameter>, as if specified in
a <command>domain</command> directive in
<filename>/etc/resolv.conf</filename>, and enable
search list processing as if the
<parameter>+search</parameter> option were given.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+dscp=value</option></term> <listitem>
<para>
Set the DSCP code point to be used when sending the
query. Valid DSCP code points are in the range
[0..63]. By default no code point is explicitly set.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]edns[=#]</option></term>
<listitem>
<para>
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. <option>+noedns</option>
clears the remembered EDNS version. EDNS is set to
0 by default.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]ednsflags[=#]</option></term>
<listitem>
<para>
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.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]ednsnegotiation</option></term>
<listitem>
<para>
Enable / disable EDNS version negotiation. By default
EDNS version negotiation is enabled.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]ednsopt[=code[:value]]</option></term>
<listitem>
<para>
Specify EDNS option with code point <option>code</option>
and optionally payload of <option>value</option> as a
hexadecimal string. <option>code</option> can be
either an EDNS option name (for example,
<literal>NSID</literal> or <literal>ECS</literal>),
or an arbitrary numeric value. <option>+noednsopt</option>
clears the EDNS options to be sent.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]expire</option></term>
<listitem>
<para>
Send an EDNS Expire option.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]fail</option></term>
<listitem>
<para>
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.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]header-only</option></term>
<listitem>
<para>
Send 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.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]identify</option></term>
<listitem>
<para>
Show [or do not show] the IP address and port number
that supplied the answer when the
<parameter>+short</parameter> 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.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]idnin</option></term>
<listitem>
<para>
Process [do not process] IDN domain names on input.
This requires IDN SUPPORT to have been enabled at
compile time.
</para>
<para>
The default is to process IDN input when standard output
is a tty. The IDN processing on input is disabled when
dig output is redirected to files, pipes, and other
non-tty file descriptors.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]idnout</option></term>
<listitem>
<para>
Convert [do not convert] puny code on output.
This requires IDN SUPPORT to have been enabled at
compile time.
</para>
<para>
The default is to process puny code on output when
standard output is a tty. The puny code processing on
output is disabled when dig output is redirected to
files, pipes, and other non-tty file descriptors.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]ignore</option></term>
<listitem>
<para>
Ignore truncation in UDP responses instead of retrying
with TCP. By default, TCP retries are performed.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]keepopen</option></term>
<listitem>
<para>
Keep the TCP socket open between queries and reuse
it rather than creating a new TCP socket for each
lookup. The default is <option>+nokeepopen</option>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]mapped</option></term>
<listitem>
<para>
Allow mapped IPv4 over IPv6 addresses to be used. The
default is <option>+mapped</option>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]multiline</option></term>
<listitem>
<para>
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 <command>dig</command>
output.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+ndots=D</option></term>
<listitem>
<para>
Set the number of dots that have to appear in
<parameter>name</parameter> to <parameter>D</parameter>
for it to be considered absolute. The default value
is that defined using the ndots statement in
<filename>/etc/resolv.conf</filename>, 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 <option>search</option>
or <option>domain</option> directive in
<filename>/etc/resolv.conf</filename> if
<option>+search</option> is set.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]nsid</option></term>
<listitem>
<para>
Include an EDNS name server ID request when sending
a query.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]nssearch</option></term>
<listitem>
<para>
When this option is set, <command>dig</command>
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.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]onesoa</option></term>
<listitem>
<para>
Print only one (starting) SOA record when performing
an AXFR. The default is to print both the starting
and ending SOA records.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]opcode=value</option></term>
<listitem>
<para>
Set [restore] the DNS message opcode to the specified
value. The default value is QUERY (0).
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]qr</option></term>
<listitem>
<para>
Toggles the display of the query message as it is sent.
By default, the query is not printed.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]question</option></term>
<listitem>
<para>
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.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]rdflag</option></term>
<listitem>
<para>
A synonym for <parameter>+[no]recurse</parameter>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]recurse</option></term>
<listitem>
<para>
Toggle the setting of the RD (recursion desired) bit
in the query. This bit is set by default, which means
<command>dig</command> normally sends recursive
queries. Recursion is automatically disabled when
using the <parameter>+nssearch</parameter> option, and
when using <parameter>+trace</parameter> except for
an initial recursive query to get the list of root
servers.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+retry=T</option></term>
<listitem>
<para>
Sets the number of times to retry UDP queries to
server to <parameter>T</parameter> instead of the
default, 2. Unlike <parameter>+tries</parameter>,
this does not include the initial query.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]rrcomments</option></term>
<listitem>
<para>
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.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]search</option></term>
<listitem>
<para>
Use [do not use] the search list defined by the
searchlist or domain directive in
<filename>resolv.conf</filename> (if any). The search
list is not used by default.
</para>
<para>
'ndots' from <filename>resolv.conf</filename> (default 1)
which may be overridden by <parameter>+ndots</parameter>
determines if the name will be treated as relative
or not and hence whether a search is eventually
performed or not.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]short</option></term>
<listitem>
<para>
Provide a terse answer. The default is to print the
answer in a verbose form. This option always has global
effect; it cannot be set globally and then overridden on
a per-lookup basis.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]showsearch</option></term>
<listitem>
<para>
Perform [do not perform] a search showing intermediate
results.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]sigchase</option></term>
<listitem>
<para>
Chase DNSSEC signature chains. Requires dig be compiled
with -DDIG_SIGCHASE. This feature is deprecated.
Use <command>delv</command> instead.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+split=W</option></term>
<listitem>
<para>
Split long hex- or base64-formatted fields in resource
records into chunks of <parameter>W</parameter>
characters (where <parameter>W</parameter> is rounded
up to the nearest multiple of 4).
<parameter>+nosplit</parameter> or
<parameter>+split=0</parameter> causes fields not to
be split at all. The default is 56 characters, or
44 characters when multiline mode is active.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]stats</option></term>
<listitem>
<para>
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 as a comment after each lookup.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]subnet=addr[/prefix-length]</option></term>
<listitem>
<para>
Send (don't send) an EDNS Client Subnet option with the
specified IP address or network prefix.
</para>
<para>
<command>dig +subnet=0.0.0.0/0</command>, or simply
<command>dig +subnet=0</command> 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
<emphasis>not</emphasis> be used when resolving
this query.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]tcp</option></term>
<listitem>
<para>
Use [do not use] TCP when querying name servers. The
default behavior is to use UDP unless a type
<literal>any</literal> or <literal>ixfr=N</literal>
query is requested, in which case the default is TCP.
AXFR queries always use TCP.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+timeout=T</option></term>
<listitem>
<para>
Sets the timeout for a query to
<parameter>T</parameter> seconds. The default
timeout is 5 seconds.
An attempt to set <parameter>T</parameter> to less
than 1 will result
in a query timeout of 1 second being applied.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]topdown</option></term>
<listitem>
<para>
When chasing DNSSEC signature chains perform a top-down
validation. Requires dig be compiled with -DDIG_SIGCHASE.
This feature is deprecated. Use <command>delv</command> instead.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]trace</option></term>
<listitem>
<para>
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,
<command>dig</command> 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.
</para> <para>
If @server is also specified, it affects only the
initial query for the root zone name servers.
</para> <para>
<command>+dnssec</command> is also set when +trace
is set to better emulate the default queries from a
nameserver.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+tries=T</option></term>
<listitem>
<para>
Sets the number of times to try UDP queries to server
to <parameter>T</parameter> instead of the default,
3. If <parameter>T</parameter> is less than or equal
to zero, the number of tries is silently rounded up
to 1.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+trusted-key=####</option></term>
<listitem>
<para>
Specifies a file containing trusted keys to be used
with <option>+sigchase</option>. Each DNSKEY record
must be on its own line.
</para> <para>
If not specified, <command>dig</command> will look
for <filename>/etc/trusted-key.key</filename> then
<filename>trusted-key.key</filename> in the current
directory.
</para> <para>
Requires dig be compiled with -DDIG_SIGCHASE.
This feature is deprecated. Use <command>delv</command> instead.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]ttlid</option></term>
<listitem>
<para>
Display [do not display] the TTL when printing the
record.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]ttlunits</option></term>
<listitem>
<para>
Display [do not display] the TTL in friendly human-readable
time units of "s", "m", "h", "d", and "w", representing
seconds, minutes, hours, days and weeks. Implies +ttlid.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]unknownformat</option></term>
<listitem>
<para>
Print 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.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]vc</option></term>
<listitem>
<para>
Use [do not use] TCP when querying name servers. This
alternate syntax to <parameter>+[no]tcp</parameter>
is provided for backwards compatibility. The "vc"
stands for "virtual circuit".
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>+[no]zflag</option></term>
<listitem>
<para>
Set [do not set] the last unassigned DNS header flag in a
DNS query. This flag is off by default.
</para>
</listitem>
</varlistentry>
</variablelist>
</para>
</refsection>
<refsection><info><title>MULTIPLE QUERIES</title></info>
<para>
The BIND 9 implementation of <command>dig </command>
supports
specifying multiple queries on the command line (in addition to
supporting the <option>-f</option> batch file option). Each of those
queries can be supplied with its own set of flags, options and query
options.
</para>
<para>
In this case, each <parameter>query</parameter> 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.
</para>
<para>
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 <option>+[no]cmd</option> option) can be
overridden by a query-specific set of query options. For example:
<programlisting>
dig +qr www.isc.org any -x 127.0.0.1 isc.org ns +noqr
</programlisting>
shows how <command>dig</command> could be used from the
command line
to make three lookups: an ANY query for <literal>www.isc.org</literal>, a
reverse lookup of 127.0.0.1 and a query for the NS records of
<literal>isc.org</literal>.
A global query option of <parameter>+qr</parameter> is
applied, so
that <command>dig</command> shows the initial query it made
for each
lookup. The final query has a local query option of
<parameter>+noqr</parameter> which means that <command>dig</command>
will not print the initial query when it looks up the NS records for
<literal>isc.org</literal>.
</para>
</refsection>
<refsection><info><title>IDN SUPPORT</title></info>
<para>
If <command>dig</command> has been built with IDN (internationalized
domain name) support, it can accept and display non-ASCII domain names.
<command>dig</command> 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, use
parameters <parameter>+noidnin</parameter> and
<parameter>+noidnout</parameter>.
</para>
</refsection>
<refsection><info><title>FILES</title></info>
<para><filename>/etc/resolv.conf</filename>
</para>
<para><filename>${HOME}/.digrc</filename>
</para>
</refsection>
<refsection><info><title>SEE ALSO</title></info>
<para><citerefentry>
<refentrytitle>delv</refentrytitle><manvolnum>1</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>host</refentrytitle><manvolnum>1</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>named</refentrytitle><manvolnum>8</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>dnssec-keygen</refentrytitle><manvolnum>8</manvolnum>
</citerefentry>,
<citetitle>RFC 1035</citetitle>.
</para>
</refsection>
<refsection><info><title>BUGS</title></info>
<para>
There are probably too many query options.
</para>
</refsection>
</refentry>