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|
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<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>dig</title>
<meta name="generator" content="DocBook XSL Stylesheets V1.78.1">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="refentry">
<a name="man.dig"></a><div class="titlepage"></div>
<div class="refnamediv">
<h2>Name</h2>
<p>
dig
— DNS lookup utility
</p>
</div>
<div class="refsynopsisdiv">
<h2>Synopsis</h2>
<div class="cmdsynopsis"><p>
<code class="command">dig</code>
[@server]
[<code class="option">-b <em class="replaceable"><code>address</code></em></code>]
[<code class="option">-c <em class="replaceable"><code>class</code></em></code>]
[<code class="option">-f <em class="replaceable"><code>filename</code></em></code>]
[<code class="option">-k <em class="replaceable"><code>filename</code></em></code>]
[<code class="option">-m</code>]
[<code class="option">-p <em class="replaceable"><code>port#</code></em></code>]
[<code class="option">-q <em class="replaceable"><code>name</code></em></code>]
[<code class="option">-t <em class="replaceable"><code>type</code></em></code>]
[<code class="option">-v</code>]
[<code class="option">-x <em class="replaceable"><code>addr</code></em></code>]
[<code class="option">-y <em class="replaceable"><code>[<span class="optional">hmac:</span>]name:key</code></em></code>]
[
[<code class="option">-4</code>]
| [<code class="option">-6</code>]
]
[name]
[type]
[class]
[queryopt...]
</p></div>
<div class="cmdsynopsis"><p>
<code class="command">dig</code>
[<code class="option">-h</code>]
</p></div>
<div class="cmdsynopsis"><p>
<code class="command">dig</code>
[global-queryopt...]
[query...]
</p></div>
</div>
<div class="refsection">
<a name="id-1.7"></a><h2>DESCRIPTION</h2>
<p><span class="command"><strong>dig</strong></span> 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 <span class="command"><strong>dig</strong></span> to
troubleshoot DNS problems because of its flexibility, ease of use and
clarity of output. Other lookup tools tend to have less functionality
than <span class="command"><strong>dig</strong></span>.
</p>
<p>
Although <span class="command"><strong>dig</strong></span> 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 <code class="option">-h</code> option is given.
Unlike earlier versions, the BIND 9 implementation of
<span class="command"><strong>dig</strong></span> allows multiple lookups to be issued
from the
command line.
</p>
<p>
Unless it is told to query a specific name server,
<span class="command"><strong>dig</strong></span> will try each of the servers listed in
<code class="filename">/etc/resolv.conf</code>. If no usable server addresses
are found, <span class="command"><strong>dig</strong></span> will send the query to the local
host.
</p>
<p>
When no command line arguments or options are given,
<span class="command"><strong>dig</strong></span> will perform an NS query for "." (the root).
</p>
<p>
It is possible to set per-user defaults for <span class="command"><strong>dig</strong></span> via
<code class="filename">${HOME}/.digrc</code>. This file is read and
any options in it
are applied before the command line arguments.
</p>
<p>
The IN and CH class names overlap with the IN and CH top level
domain names. Either use the <code class="option">-t</code> and
<code class="option">-c</code> options to specify the type and class,
use the <code class="option">-q</code> the specify the domain name, or
use "IN." and "CH." when looking up these top level domains.
</p>
</div>
<div class="refsection">
<a name="id-1.8"></a><h2>SIMPLE USAGE</h2>
<p>
A typical invocation of <span class="command"><strong>dig</strong></span> looks like:
</p>
<pre class="programlisting"> dig @server name type </pre>
<p>
where:
</p>
<div class="variablelist"><dl class="variablelist">
<dt><span class="term"><code class="constant">server</code></span></dt>
<dd>
<p>
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
<em class="parameter"><code>server</code></em> argument is a hostname,
<span class="command"><strong>dig</strong></span> resolves that name before querying
that name server.
</p>
<p>
If no <em class="parameter"><code>server</code></em> argument is
provided, <span class="command"><strong>dig</strong></span> consults
<code class="filename">/etc/resolv.conf</code>; if an
address is found there, it queries the name server at
that address. If either of the <code class="option">-4</code> or
<code class="option">-6</code> options are in use, then
only addresses for the corresponding transport
will be tried. If no usable addresses are found,
<span class="command"><strong>dig</strong></span> will send the query to the
local host. The reply from the name server that
responds is displayed.
</p>
</dd>
<dt><span class="term"><code class="constant">name</code></span></dt>
<dd>
<p>
is the name of the resource record that is to be looked up.
</p>
</dd>
<dt><span class="term"><code class="constant">type</code></span></dt>
<dd>
<p>
indicates what type of query is required —
ANY, A, MX, SIG, etc.
<em class="parameter"><code>type</code></em> can be any valid query
type. If no
<em class="parameter"><code>type</code></em> argument is supplied,
<span class="command"><strong>dig</strong></span> will perform a lookup for an
A record.
</p>
</dd>
</dl></div>
<p>
</p>
</div>
<div class="refsection">
<a name="id-1.9"></a><h2>OPTIONS</h2>
<div class="variablelist"><dl class="variablelist">
<dt><span class="term">-4</span></dt>
<dd>
<p>
Use IPv4 only.
</p>
</dd>
<dt><span class="term">-6</span></dt>
<dd>
<p>
Use IPv6 only.
</p>
</dd>
<dt><span class="term">-b <em class="replaceable"><code>address[<span class="optional">#port</span>]</code></em></span></dt>
<dd>
<p>
Set the source IP address of the query.
The <em class="parameter"><code>address</code></em> 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>"
</p>
</dd>
<dt><span class="term">-c <em class="replaceable"><code>class</code></em></span></dt>
<dd>
<p>
Set the query class. The
default <em class="parameter"><code>class</code></em> is IN; other classes
are HS for Hesiod records or CH for Chaosnet records.
</p>
</dd>
<dt><span class="term">-f <em class="replaceable"><code>file</code></em></span></dt>
<dd>
<p>
Batch mode: <span class="command"><strong>dig</strong></span> reads a list of lookup
requests to process from the
given <em class="parameter"><code>file</code></em>. Each line in the file
should be organized in the same way they would be
presented as queries to
<span class="command"><strong>dig</strong></span> using the command-line interface.
</p>
</dd>
<dt><span class="term">-i</span></dt>
<dd>
<p>
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.
</p>
</dd>
<dt><span class="term">-k <em class="replaceable"><code>keyfile</code></em></span></dt>
<dd>
<p>
Sign queries using TSIG using a key read from the given file.
Key files can be generated using
<span class="citerefentry">
<span class="refentrytitle">tsig-keygen</span>(8)
</span>.
When using TSIG authentication with <span class="command"><strong>dig</strong></span>,
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 <span class="command"><strong>key</strong></span>
and <span class="command"><strong>server</strong></span> statements in
<code class="filename">named.conf</code>.
</p>
</dd>
<dt><span class="term">-m</span></dt>
<dd>
<p>
Enable memory usage debugging.
</p>
</dd>
<dt><span class="term">-p <em class="replaceable"><code>port</code></em></span></dt>
<dd>
<p>
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.
</p>
</dd>
<dt><span class="term">-q <em class="replaceable"><code>name</code></em></span></dt>
<dd>
<p>
The domain name to query. This is useful to distinguish
the <em class="parameter"><code>name</code></em> from other arguments.
</p>
</dd>
<dt><span class="term">-t <em class="replaceable"><code>type</code></em></span></dt>
<dd>
<p>
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 <code class="option">-x</code>
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
<em class="parameter"><code>type</code></em> to <code class="literal">ixfr=N</code>.
The incremental zone transfer will contain the changes
made to the zone since the serial number in the zone's SOA
record was
<em class="parameter"><code>N</code></em>.
</p>
<p>
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.
</p>
</dd>
<dt><span class="term">-u</span></dt>
<dd>
<p>
Print query times in microseconds instead of milliseconds.
</p>
</dd>
<dt><span class="term">-v</span></dt>
<dd>
<p>
Print the version number and exit.
</p>
</dd>
<dt><span class="term">-x <em class="replaceable"><code>addr</code></em></span></dt>
<dd>
<p>
Simplified reverse lookups, for mapping addresses to
names. The <em class="parameter"><code>addr</code></em> is an IPv4 address
in dotted-decimal notation, or a colon-delimited IPv6
address. When the <code class="option">-x</code> is used, there is no
need to provide
the <em class="parameter"><code>name</code></em>, <em class="parameter"><code>class</code></em>
and <em class="parameter"><code>type</code></em>
arguments. <span class="command"><strong>dig</strong></span> automatically performs a
lookup for a name like
<code class="literal">94.2.0.192.in-addr.arpa</code> 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 <code class="option">-i</code>
option).
</p>
</dd>
<dt><span class="term">-y <em class="replaceable"><code>[<span class="optional">hmac:</span>]keyname:secret</code></em></span></dt>
<dd>
<p>
Sign queries using TSIG with the given authentication key.
<em class="parameter"><code>keyname</code></em> is the name of the key, and
<em class="parameter"><code>secret</code></em> is the base64 encoded shared secret.
<em class="parameter"><code>hmac</code></em> is the name of the key algorithm;
valid choices are <code class="literal">hmac-md5</code>,
<code class="literal">hmac-sha1</code>, <code class="literal">hmac-sha224</code>,
<code class="literal">hmac-sha256</code>, <code class="literal">hmac-sha384</code>, or
<code class="literal">hmac-sha512</code>. If <em class="parameter"><code>hmac</code></em>
is not specified, the default is <code class="literal">hmac-md5</code>
or if MD5 was disabled <code class="literal">hmac-sha256</code>.
</p>
<p>
NOTE: You should use the <code class="option">-k</code> option and
avoid the <code class="option">-y</code> option, because
with <code class="option">-y</code> the shared secret is supplied as
a command line argument in clear text. This may be visible
in the output from
<span class="citerefentry">
<span class="refentrytitle">ps</span>(1)
</span>
or in a history file maintained by the user's shell.
</p>
</dd>
</dl></div>
</div>
<div class="refsection">
<a name="id-1.10"></a><h2>QUERY OPTIONS</h2>
<p><span class="command"><strong>dig</strong></span>
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.
</p>
<p>
Each query option is identified by a keyword preceded by a plus sign
(<code class="literal">+</code>). Some keywords set or reset an
option. These may be preceded
by the string <code class="literal">no</code> to negate the meaning of
that keyword. Other
keywords assign values to options like the timeout interval. They
have the form <code class="option">+keyword=value</code>.
Keywords may be abbreviated, provided the abbreviation is
unambiguous; for example, <code class="literal">+cd</code> is equivalent
to <code class="literal">+cdflag</code>.
The query options are:
</p>
<div class="variablelist"><dl class="variablelist">
<dt><span class="term"><code class="option">+[no]aaflag</code></span></dt>
<dd>
<p>
A synonym for <em class="parameter"><code>+[no]aaonly</code></em>.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]aaonly</code></span></dt>
<dd>
<p>
Sets the "aa" flag in the query.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]additional</code></span></dt>
<dd>
<p>
Display [do not display] the additional section of a
reply. The default is to display it.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]adflag</code></span></dt>
<dd>
<p>
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.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]all</code></span></dt>
<dd>
<p>
Set or clear all display flags.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]answer</code></span></dt>
<dd>
<p>
Display [do not display] the answer section of a
reply. The default is to display it.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]authority</code></span></dt>
<dd>
<p>
Display [do not display] the authority section of a
reply. The default is to display it.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]badcookie</code></span></dt>
<dd>
<p>
Retry lookup with the new server cookie if a
BADCOOKIE response is received.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]besteffort</code></span></dt>
<dd>
<p>
Attempt to display the contents of messages which are
malformed. The default is to not display malformed
answers.
</p>
</dd>
<dt><span class="term"><code class="option">+bufsize=B</code></span></dt>
<dd>
<p>
Set the UDP message buffer size advertised using EDNS0
to <em class="parameter"><code>B</code></em> 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.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]cdflag</code></span></dt>
<dd>
<p>
Set [do not set] the CD (checking disabled) bit in
the query. This requests the server to not perform
DNSSEC validation of responses.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]class</code></span></dt>
<dd>
<p>
Display [do not display] the CLASS when printing the
record.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]cmd</code></span></dt>
<dd>
<p>
Toggles the printing of the initial comment in the
output identifying the version of <span class="command"><strong>dig</strong></span>
and the query options that have been applied. This
comment is printed by default.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]comments</code></span></dt>
<dd>
<p>
Toggle the display of comment lines in the output.
The default is to print comments.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]cookie[<span class="optional">=####</span>]</code></span></dt>
<dd>
<p>
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 <code class="option">+cookie</code>.
</p>
<p>
<span class="command"><strong>+cookie</strong></span> is also set when +trace
is set to better emulate the default queries from a
nameserver.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]crypto</code></span></dt>
<dd>
<p>
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 ]".
</p>
</dd>
<dt><span class="term"><code class="option">+[no]defname</code></span></dt>
<dd>
<p>
Deprecated, treated as a synonym for
<em class="parameter"><code>+[no]search</code></em>
</p>
</dd>
<dt><span class="term"><code class="option">+[no]dnssec</code></span></dt>
<dd>
<p>
Requests DNSSEC records be sent by setting the DNSSEC
OK bit (DO) in the OPT record in the additional section
of the query.
</p>
</dd>
<dt><span class="term"><code class="option">+domain=somename</code></span></dt>
<dd>
<p>
Set the search list to contain the single domain
<em class="parameter"><code>somename</code></em>, as if specified in
a <span class="command"><strong>domain</strong></span> directive in
<code class="filename">/etc/resolv.conf</code>, and enable
search list processing as if the
<em class="parameter"><code>+search</code></em> option were given.
</p>
</dd>
<dt><span class="term"><code class="option">+dscp=value</code></span></dt>
<dd>
<p>
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.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]edns[=#]</code></span></dt>
<dd>
<p>
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. <code class="option">+noedns</code>
clears the remembered EDNS version. EDNS is set to
0 by default.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]ednsflags[=#]</code></span></dt>
<dd>
<p>
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.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]ednsnegotiation</code></span></dt>
<dd>
<p>
Enable / disable EDNS version negotiation. By default
EDNS version negotiation is enabled.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]ednsopt[=code[:value]]</code></span></dt>
<dd>
<p>
Specify EDNS option with code point <code class="option">code</code>
and optionally payload of <code class="option">value</code> as a
hexadecimal string. <code class="option">code</code> can be
either an EDNS option name (for example,
<code class="literal">NSID</code> or <code class="literal">ECS</code>),
or an arbitrary numeric value. <code class="option">+noednsopt</code>
clears the EDNS options to be sent.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]expire</code></span></dt>
<dd>
<p>
Send an EDNS Expire option.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]fail</code></span></dt>
<dd>
<p>
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.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]header-only</code></span></dt>
<dd>
<p>
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.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]identify</code></span></dt>
<dd>
<p>
Show [or do not show] the IP address and port number
that supplied the answer when the
<em class="parameter"><code>+short</code></em> 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.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]idnin</code></span></dt>
<dd>
<p>
Process [do not process] IDN domain names on input.
This requires IDN SUPPORT to have been enabled at
compile time. The default is to process IDN input.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]idnout</code></span></dt>
<dd>
<p>
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.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]ignore</code></span></dt>
<dd>
<p>
Ignore truncation in UDP responses instead of retrying
with TCP. By default, TCP retries are performed.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]keepopen</code></span></dt>
<dd>
<p>
Keep the TCP socket open between queries and reuse
it rather than creating a new TCP socket for each
lookup. The default is <code class="option">+nokeepopen</code>.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]mapped</code></span></dt>
<dd>
<p>
Allow mapped IPv4 over IPv6 addresses to be used. The
default is <code class="option">+mapped</code>.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]multiline</code></span></dt>
<dd>
<p>
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 <span class="command"><strong>dig</strong></span>
output.
</p>
</dd>
<dt><span class="term"><code class="option">+ndots=D</code></span></dt>
<dd>
<p>
Set the number of dots that have to appear in
<em class="parameter"><code>name</code></em> to <em class="parameter"><code>D</code></em>
for it to be considered absolute. The default value
is that defined using the ndots statement in
<code class="filename">/etc/resolv.conf</code>, 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 <code class="option">search</code>
or <code class="option">domain</code> directive in
<code class="filename">/etc/resolv.conf</code> if
<code class="option">+search</code> is set.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]nsid</code></span></dt>
<dd>
<p>
Include an EDNS name server ID request when sending
a query.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]nssearch</code></span></dt>
<dd>
<p>
When this option is set, <span class="command"><strong>dig</strong></span>
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.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]onesoa</code></span></dt>
<dd>
<p>
Print only one (starting) SOA record when performing
an AXFR. The default is to print both the starting
and ending SOA records.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]opcode=value</code></span></dt>
<dd>
<p>
Set [restore] the DNS message opcode to the specified
value. The default value is QUERY (0).
</p>
</dd>
<dt><span class="term"><code class="option">+[no]qr</code></span></dt>
<dd>
<p>
Print [do not print] the query as it is sent. By
default, the query is not printed.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]question</code></span></dt>
<dd>
<p>
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.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]rdflag</code></span></dt>
<dd>
<p>
A synonym for <em class="parameter"><code>+[no]recurse</code></em>.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]recurse</code></span></dt>
<dd>
<p>
Toggle the setting of the RD (recursion desired) bit
in the query. This bit is set by default, which means
<span class="command"><strong>dig</strong></span> normally sends recursive
queries. Recursion is automatically disabled when
the <em class="parameter"><code>+nssearch</code></em> or
<em class="parameter"><code>+trace</code></em> query options are used.
</p>
</dd>
<dt><span class="term"><code class="option">+retry=T</code></span></dt>
<dd>
<p>
Sets the number of times to retry UDP queries to
server to <em class="parameter"><code>T</code></em> instead of the
default, 2. Unlike <em class="parameter"><code>+tries</code></em>,
this does not include the initial query.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]rrcomments</code></span></dt>
<dd>
<p>
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.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]search</code></span></dt>
<dd>
<p>
Use [do not use] the search list defined by the
searchlist or domain directive in
<code class="filename">resolv.conf</code> (if any). The search
list is not used by default.
</p>
<p>
'ndots' from <code class="filename">resolv.conf</code> (default 1)
which may be overridden by <em class="parameter"><code>+ndots</code></em>
determines if the name will be treated as relative
or not and hence whether a search is eventually
performed or not.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]short</code></span></dt>
<dd>
<p>
Provide a terse answer. The default is to print the
answer in a verbose form.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]showsearch</code></span></dt>
<dd>
<p>
Perform [do not perform] a search showing intermediate
results.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]sigchase</code></span></dt>
<dd>
<p>
Chase DNSSEC signature chains. Requires dig be compiled
with -DDIG_SIGCHASE. This feature is deprecated.
Use <span class="command"><strong>delv</strong></span> instead.
</p>
</dd>
<dt><span class="term"><code class="option">+split=W</code></span></dt>
<dd>
<p>
Split long hex- or base64-formatted fields in resource
records into chunks of <em class="parameter"><code>W</code></em>
characters (where <em class="parameter"><code>W</code></em> is rounded
up to the nearest multiple of 4).
<em class="parameter"><code>+nosplit</code></em> or
<em class="parameter"><code>+split=0</code></em> causes fields not to
be split at all. The default is 56 characters, or
44 characters when multiline mode is active.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]stats</code></span></dt>
<dd>
<p>
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.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]subnet=addr[/prefix-length]</code></span></dt>
<dd>
<p>
Send (don't send) an EDNS Client Subnet option with the
specified IP address or network prefix.
</p>
<p>
<span class="command"><strong>dig +subnet=0.0.0.0/0</strong></span>, or simply
<span class="command"><strong>dig +subnet=0</strong></span> 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
<span class="emphasis"><em>not</em></span> be used when resolving
this query.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]tcp</code></span></dt>
<dd>
<p>
Use [do not use] TCP when querying name servers. The
default behavior is to use UDP unless a type
<code class="literal">any</code> or <code class="literal">ixfr=N</code>
query is requested, in which case the default is TCP.
AXFR queries always use TCP.
</p>
</dd>
<dt><span class="term"><code class="option">+timeout=T</code></span></dt>
<dd>
<p>
Sets the timeout for a query to
<em class="parameter"><code>T</code></em> seconds. The default
timeout is 5 seconds.
An attempt to set <em class="parameter"><code>T</code></em> to less
than 1 will result
in a query timeout of 1 second being applied.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]topdown</code></span></dt>
<dd>
<p>
When chasing DNSSEC signature chains perform a top-down
validation. Requires dig be compiled with -DDIG_SIGCHASE.
This feature is deprecated. Use <span class="command"><strong>delv</strong></span> instead.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]trace</code></span></dt>
<dd>
<p>
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,
<span class="command"><strong>dig</strong></span> 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.
</p> <p>
If @server is also specified, it affects only the
initial query for the root zone name servers.
</p> <p>
<span class="command"><strong>+dnssec</strong></span> is also set when +trace
is set to better emulate the default queries from a
nameserver.
</p>
</dd>
<dt><span class="term"><code class="option">+tries=T</code></span></dt>
<dd>
<p>
Sets the number of times to try UDP queries to server
to <em class="parameter"><code>T</code></em> instead of the default,
3. If <em class="parameter"><code>T</code></em> is less than or equal
to zero, the number of tries is silently rounded up
to 1.
</p>
</dd>
<dt><span class="term"><code class="option">+trusted-key=####</code></span></dt>
<dd>
<p>
Specifies a file containing trusted keys to be used
with <code class="option">+sigchase</code>. Each DNSKEY record
must be on its own line.
</p> <p>
If not specified, <span class="command"><strong>dig</strong></span> will look
for <code class="filename">/etc/trusted-key.key</code> then
<code class="filename">trusted-key.key</code> in the current
directory.
</p> <p>
Requires dig be compiled with -DDIG_SIGCHASE.
This feature is deprecated. Use <span class="command"><strong>delv</strong></span> instead.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]ttlid</code></span></dt>
<dd>
<p>
Display [do not display] the TTL when printing the
record.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]ttlunits</code></span></dt>
<dd>
<p>
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.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]unknownformat</code></span></dt>
<dd>
<p>
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.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]vc</code></span></dt>
<dd>
<p>
Use [do not use] TCP when querying name servers. This
alternate syntax to <em class="parameter"><code>+[no]tcp</code></em>
is provided for backwards compatibility. The "vc"
stands for "virtual circuit".
</p>
</dd>
<dt><span class="term"><code class="option">+[no]zflag</code></span></dt>
<dd>
<p>
Set [do not set] the last unassigned DNS header flag in a
DNS query. This flag is off by default.
</p>
</dd>
</dl></div>
<p>
</p>
</div>
<div class="refsection">
<a name="id-1.11"></a><h2>MULTIPLE QUERIES</h2>
<p>
The BIND 9 implementation of <span class="command"><strong>dig </strong></span>
supports
specifying multiple queries on the command line (in addition to
supporting the <code class="option">-f</code> batch file option). Each of those
queries can be supplied with its own set of flags, options and query
options.
</p>
<p>
In this case, each <em class="parameter"><code>query</code></em> 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.
</p>
<p>
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 <code class="option">+[no]cmd</code> option) can be
overridden by a query-specific set of query options. For example:
</p>
<pre class="programlisting">
dig +qr www.isc.org any -x 127.0.0.1 isc.org ns +noqr
</pre>
<p>
shows how <span class="command"><strong>dig</strong></span> could be used from the
command line
to make three lookups: an ANY query for <code class="literal">www.isc.org</code>, a
reverse lookup of 127.0.0.1 and a query for the NS records of
<code class="literal">isc.org</code>.
A global query option of <em class="parameter"><code>+qr</code></em> is
applied, so
that <span class="command"><strong>dig</strong></span> shows the initial query it made
for each
lookup. The final query has a local query option of
<em class="parameter"><code>+noqr</code></em> which means that <span class="command"><strong>dig</strong></span>
will not print the initial query when it looks up the NS records for
<code class="literal">isc.org</code>.
</p>
</div>
<div class="refsection">
<a name="id-1.12"></a><h2>IDN SUPPORT</h2>
<p>
If <span class="command"><strong>dig</strong></span> has been built with IDN (internationalized
domain name) support, it can accept and display non-ASCII domain names.
<span class="command"><strong>dig</strong></span> 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 <em class="parameter"><code>+noidnin</code></em> and
<em class="parameter"><code>+noidnout</code></em>.
</p>
</div>
<div class="refsection">
<a name="id-1.13"></a><h2>FILES</h2>
<p><code class="filename">/etc/resolv.conf</code>
</p>
<p><code class="filename">${HOME}/.digrc</code>
</p>
</div>
<div class="refsection">
<a name="id-1.14"></a><h2>SEE ALSO</h2>
<p><span class="citerefentry">
<span class="refentrytitle">delv</span>(1)
</span>,
<span class="citerefentry">
<span class="refentrytitle">host</span>(1)
</span>,
<span class="citerefentry">
<span class="refentrytitle">named</span>(8)
</span>,
<span class="citerefentry">
<span class="refentrytitle">dnssec-keygen</span>(8)
</span>,
<em class="citetitle">RFC 1035</em>.
</p>
</div>
<div class="refsection">
<a name="id-1.15"></a><h2>BUGS</h2>
<p>
There are probably too many query options.
</p>
</div>
</div></body>
</html>
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