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<refentry id="man.dig">

<refentryinfo>

<date>February 19, 2014</date>

</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>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>

<holder>Internet Systems Consortium, Inc. ("ISC")</holder>

</copyright>

<copyright>

<year>2000</year>

<year>2001</year>

<year>2002</year>

<year>2003</year>

<holder>Internet Software Consortium.</holder>

</copyright>

</docinfo>

<refsynopsisdiv>

<cmdsynopsis>

<command>dig</command>

<arg choice="opt">@server</arg>

<arg><option>-b <replaceable class="parameter">address</replaceable></option></arg>

<arg><option>-c <replaceable class="parameter">class</replaceable></option></arg>

<arg><option>-f <replaceable class="parameter">filename</replaceable></option></arg>

<arg><option>-k <replaceable class="parameter">filename</replaceable></option></arg>

<arg><option>-m</option></arg>

<arg><option>-p <replaceable class="parameter">port#</replaceable></option></arg>

<arg><option>-q <replaceable class="parameter">name</replaceable></option></arg>

<arg><option>-t <replaceable class="parameter">type</replaceable></option></arg>

<arg><option>-v</option></arg>

<arg><option>-x <replaceable class="parameter">addr</replaceable></option></arg>

<arg><option>-y <replaceable class="parameter"><optional>hmac:</optional>name:key</replaceable></option></arg>

<arg><option>-4</option></arg>

<arg><option>-6</option></arg>

<arg choice="opt">name</arg>

<arg choice="opt">type</arg>

<arg choice="opt">class</arg>

<arg choice="opt" rep="repeat">queryopt</arg>

</cmdsynopsis>

<cmdsynopsis>

<command>dig</command>

<arg><option>-h</option></arg>

</cmdsynopsis>

<cmdsynopsis>

<command>dig</command>

<arg choice="opt" rep="repeat">global-queryopt</arg>

<arg choice="opt" rep="repeat">query</arg>

</cmdsynopsis>

</refsynopsisdiv>

<refsect1>

<title>DESCRIPTION</title>

<para><command>dig</command>

(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 <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.

</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>

</refsect1>

<refsect1>

<title>SIMPLE USAGE</title>

<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 &mdash;

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>

</refsect1>

<refsect1>

<title>OPTIONS</title>

<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 "#&lt;port&gt;"

</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 RFC1886 IP6.INT

domain, which is no longer in use. Obsolete bit string

label queries (RFC2874) 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

</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 defaut port 53. This option would be used

to test a name server that has been configured to listen

for queries on a non-standard port number.

</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>-t <replaceable class="parameter">type</replaceable></term>

<listitem>

<para>

The resource record type to query. It can be any valid query type

which is

supported in BIND 9. The default query type is "A", unless the

<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>

</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>.

</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>

</refsect1>

<refsect1>

<title>QUERY OPTIONS</title>

<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>.

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]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]cl</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

comment is printed by default.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>+[no]comments</option></term>

<listitem>

<para>

Toggle the display of comment lines in the output.

The default is to print comments.

</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>+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]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]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>

Print [do not print] the query as it is sent. By

default, the query is not printed.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>+[no]question</option></term>

<listitem>

<para>

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.

</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

the <parameter>+nssearch</parameter> or

<parameter>+trace</parameter> query options are used.

</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.

</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.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>+[no]sit<optional>=####</optional></option></term>

<listitem>

<para>

Send a Source Identity Token EDNS option, with optional

value. Replaying a SIT from a previous response will

allow the server to identify a previous client. The

default is <option>+nosit</option>. Currently using

experimental value 65001 for the option code.

</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>

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.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>+[no]subnet=addr/prefix</option></term>

<listitem>

<para>

Send an EDNS Client Subnet option with the specified

IP address or network prefix.

</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 an

<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.

</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>

<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.

</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]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>

</refsect1>

<refsect1>

<title>MULTIPLE QUERIES</title>

<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>

</refsect1>

<refsect1>

<title>IDN SUPPORT</title>

<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, defines

the <envar>IDN_DISABLE</envar> environment variable.

The IDN support is disabled if the variable is set when

<command>dig</command> runs.

</para>

</refsect1>

<refsect1>

<title>FILES</title>

<para><filename>/etc/resolv.conf</filename>

</para>

<para><filename>${HOME}/.digrc</filename>

</para>

</refsect1>

<refsect1>

<title>SEE ALSO</title>

<para><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>RFC1035</citetitle>.

</para>

</refsect1>

<refsect1>

<title>BUGS</title>

<para>

There are probably too many query options.

</para>

</refsect1>

</refentry><!--