DIG(1)

Look up DNS records and inspect DNS replies. Static snapshot from Ubuntu 24.04.

DIG(1) BIND 9 DIG(1)

NAME
dig - DNS lookup utility

SYNOPSIS
dig [@server] [-b address] [-c class] [-f filename] [-k filename] [-m] [-p port#]
[-q name] [-t type] [-v] [-x addr] [-y [hmac:]name:key] [ [-4] | [-6] ] [name]
[type] [class] [queryopt...]

dig [-h]

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

DESCRIPTION
dig is a flexible tool for interrogating DNS name servers. It performs DNS
lookups and displays the answers that are returned from the name server(s) that
were queried. Most DNS administrators use dig to troubleshoot DNS problems be‐
cause of its flexibility, ease of use, and clarity of output. Other lookup tools
tend to have less functionality than dig.

Although dig is normally used with command-line arguments, it also has a batch
mode of operation for reading lookup requests from a file. A brief summary of its
command-line arguments and options is printed when the -h option is given. The
BIND 9 implementation of dig allows multiple lookups to be issued from the com‐
mand line.

Unless it is told to query a specific name server, dig tries each of the servers
listed in /etc/resolv.conf. If no usable server addresses are found, dig sends
the query to the local host.

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

It is possible to set per-user defaults for dig via ${HOME}/.digrc. This file is
read and any options in it are applied before the command-line arguments. The -r
option disables this feature, for scripts that need predictable behavior.

The IN and CH class names overlap with the IN and CH top-level domain names. Ei‐
ther use the -t and -c options to specify the type and class, use the -q to spec‐
ify the domain name, or use "IN." and "CH." when looking up these top-level do‐
mains.

SIMPLE USAGE
A typical invocation of dig looks like:

dig @server name type

where:

server 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 server argument is a hostname, dig resolves
that name before querying that name server.

If no server argument is provided, dig consults /etc/resolv.conf; if an
address is found there, it queries the name server at that address. If ei‐
ther of the -4 or -6 options are in use, then only addresses for the cor‐
responding transport are tried. If no usable addresses are found, dig
sends the query to the local host. The reply from the name server that re‐
sponds is displayed.

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

type indicates what type of query is required - ANY, A, MX, SIG, etc. type can
be any valid query type. If no type argument is supplied, dig performs a
lookup for an A record.

OPTIONS
-4 This option indicates that only IPv4 should be used.

-6 This option indicates that only IPv6 should be used.

-b address[#port]
This option sets the source IP address of the query. The address 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.

-c class
This option sets the query class. The default class is IN; other classes
are HS for Hesiod records or CH for Chaosnet records.

-f file
This option sets batch mode, in which dig reads a list of lookup requests
to process from the given file. Each line in the file should be organized
in the same way it would be presented as a query to dig using the com‐
mand-line interface.

-h Print a usage summary.

-k keyfile
This option tells dig to sign queries using TSIG or SIG(0) using a key
read from the given file. Key files can be generated using tsig-keygen.
When using TSIG authentication with dig, the name server that is queried
needs to know the key and algorithm that is being used. In BIND, this is
done by providing appropriate key and server statements in named.conf for
TSIG and by looking up the KEY record in zone data for SIG(0).

-m This option enables memory usage debugging.

-p port
This option sends the query to a non-standard port on the server, instead
of the default port 53. This option is used to test a name server that has
been configured to listen for queries on a non-standard port number.

-q name
This option specifies the domain name to query. This is useful to distin‐
guish the name from other arguments.

-r This option indicates that options from ${HOME}/.digrc should not be read.
This is useful for scripts that need predictable behavior.

-t type
This option indicates the resource record type to query, which 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 -x option is supplied to indicate a reverse lookup.
A zone transfer can be requested by specifying a type of AXFR. When an in‐
cremental zone transfer (IXFR) is required, set the type to ixfr=N. The
incremental zone transfer contains all changes made to the zone since the
serial number in the zone's SOA record was N.

All resource record types can be expressed as TYPEnn, where nn is the num‐
ber of the type. If the resource record type is not supported in BIND 9,
the result is displayed as described in RFC 3597.

-u This option indicates that print query times should be provided in mi‐
croseconds instead of milliseconds.

-v This option prints the version number and exits.

-x addr
This option sets simplified reverse lookups, for mapping addresses to
names. The addr is an IPv4 address in dotted-decimal notation, or a
colon-delimited IPv6 address. When the -x option is used, there is no need
to provide the name, class, and type arguments. dig automatically per‐
forms a lookup for a name like 94.2.0.192.in-addr.arpa 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.

-y [hmac:]keyname:secret
This option signs queries using TSIG with the given authentication key.
keyname is the name of the key, and secret is the base64-encoded shared
secret. hmac is the name of the key algorithm; valid choices are hmac-md5,
hmac-sha1, hmac-sha224, hmac-sha256, hmac-sha384, or hmac-sha512. If hmac
is not specified, the default is hmac-md5; if MD5 was disabled, the de‐
fault is hmac-sha256.

NOTE:
Only the -k option should be used, rather than the -y option, because with -y
the shared secret is supplied as a command-line argument in clear text. This
may be visible in the output from ps1 or in a history file maintained by the
user's shell.

QUERY OPTIONS
dig 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 de‐
termine the timeout and retry strategies.

Each query option is identified by a keyword preceded by a plus sign (+). Some
keywords set or reset an option; these may be preceded by the string no to negate
the meaning of that keyword. Other keywords assign values to options, like the
timeout interval. They have the form +keyword=value. Keywords may be abbreviated,
provided the abbreviation is unambiguous; for example, +cd is equivalent to
+cdflag. The query options are:

+aaflag, +noaaflag
This option is a synonym for +aaonly, +noaaonly.

+aaonly, +noaaonly
This option sets the aa flag in the query.

+additional, +noadditional
This option displays [or does not display] the additional section of a re‐
ply. The default is to display it.

+adflag, +noadflag
This option sets [or does 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 been validated as secure, according to the secu‐
rity policy of the server. AD=1 indicates that all records have been vali‐
dated as secure and the answer is not from a OPT-OUT range. AD=0 indicates
that some part of the answer was insecure or not validated. This bit is
set by default.

+all, +noall
This option sets or clears all display flags.

+answer, +noanswer
This option displays [or does not display] the answer section of a reply.
The default is to display it.

+authority, +noauthority
This option displays [or does not display] the authority section of a re‐
ply. The default is to display it.

+badcookie, +nobadcookie
This option retries the lookup with a new server cookie if a BADCOOKIE re‐
sponse is received.

+besteffort, +nobesteffort
This option attempts to display the contents of messages which are mal‐
formed. The default is to not display malformed answers.

+bufsize[=B]
This option sets the UDP message buffer size advertised using EDNS0 to B
bytes. The maximum and minimum sizes of this buffer are 65535 and 0, re‐
spectively. +bufsize restores the default buffer size.

+cd, +cdflag, +nocdflag
This option sets [or does not set] the CD (checking disabled) bit in the
query. This requests the server to not perform DNSSEC validation of re‐
sponses.

+class, +noclass
This option displays [or does not display] the CLASS when printing the
record.

+cmd, +nocmd
This option toggles the printing of the initial comment in the output,
identifying the version of dig and the query options that have been ap‐
plied. This option always has a global effect; it cannot be set globally
and then overridden on a per-lookup basis. The default is to print this
comment.

+coflag, +co, +nocoflag, +noco
This option sets [or does not set] the CO (Compact denial of existence Ok)
EDNS bit in the query. If set, it tells servers that Compact Denial of
Existence responses are acceptable when replying to queries. The default
is +nocoflag.

+comments, +nocomments
This option toggles the display of some comment lines in the output, with
information about the packet header and OPT pseudosection, and the names
of the response section. The default is to print these comments.

Other types of comments in the output are not affected by this option, but
can be controlled using other command-line switches. These include +cmd,
+question, +stats, and +rrcomments.

+cookie=####, +nocookie
This option sends [or does not send] a COOKIE EDNS option, with an op‐
tional value. Replaying a COOKIE from a previous response allows the
server to identify a previous client. The default is +cookie.

+cookie is also set when +trace is set to better emulate the default
queries from a nameserver.

+crypto, +nocrypto
This option toggles the display of cryptographic fields in DNSSEC records.
The contents of these fields are unnecessary for debugging 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 re‐
placed by the string [omitted] or, in the DNSKEY case, the key ID is dis‐
played as the replacement, e.g. [ key id = value ].

+defname, +nodefname
This option, which is deprecated, is treated as a synonym for +search,
+nosearch.

+dns64prefix, +nodns64prefix
Lookup IPV4ONLY.ARPA AAAA and print any DNS64 prefixes found.

+dnssec, +do, +nodnssec, +nodo
This option requests that DNSSEC records be sent by setting the DNSSEC OK
(DO) bit in the OPT record in the additional section of the query.

+domain=somename
This option sets the search list to contain the single domain somename, as
if specified in a domain directive in /etc/resolv.conf, and enables search
list processing as if the +search option were given.

+dscp=value
This option formerly set the DSCP value used when sending a query. It is
now obsolete, and has no effect.

+edns[=#], +noedns
This option specifies the EDNS version to query with. Valid values are 0
to 255. Setting the EDNS version causes an EDNS query to be sent.
+noedns clears the remembered EDNS version. EDNS is set to 0 by default.

+ednsflags[=#], +noednsflags
This option sets the must-be-zero EDNS flags bits (Z bits) to the speci‐
fied value. Decimal, hex, and octal encodings are accepted. Setting a
named flag (e.g. DO, CO) is silently ignored. By default, no Z bits are
set.

+ednsnegotiation, +noednsnegotiation
This option enables/disables EDNS version negotiation. By default, EDNS
version negotiation is enabled.

+ednsopt[=code[:value]], +noednsopt
This option specifies the EDNS option with code point code and an optional
payload of value as a hexadecimal string. code can be either an EDNS op‐
tion name (for example, NSID or ECS) or an arbitrary numeric value.
+noednsopt clears the EDNS options to be sent.

+expire, +noexpire
This option sends an EDNS Expire option.

+fail, +nofail
This option indicates that named should try [or not try] the next server
if a SERVFAIL is received. The default is to not try the next server,
which is the reverse of normal stub resolver behavior.

+fuzztime[=value], +nofuzztime
This option allows the signing time to be specified when generating signed
messages. If a value is specified it is the seconds since 00:00:00 Janu‐
ary 1, 1970 UTC ignoring leap seconds. If no value is specified
1646972129 (Fri 11 Mar 2022 04:15:29 UTC) is used. The default is +nofuz‐
ztime and the current time is used.

+header-only, +noheader-only
This option sends 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.

+https[=value], +nohttps
This option indicates whether to use DNS over HTTPS (DoH) when querying
name servers. When this option is in use, the port number defaults to
443. The HTTP POST request mode is used when sending the query.

If value is specified, it will be used as the HTTP endpoint in the query
URI; the default is /dns-query. So, for example, dig @example.com +https
will use the URI https://example.com/dns-query.

+https-get[=value], +nohttps-get
Similar to +https, except that the HTTP GET request mode is used when
sending the query.

+https-post[=value], +nohttps-post
Same as +https.

+http-plain[=value], +nohttp-plain
Similar to +https, except that HTTP queries will be sent over a non-en‐
crypted channel. When this option is in use, the port number defaults to
80 and the HTTP request mode is POST.

+http-plain-get[=value], +nohttp-plain-get
Similar to +http-plain, except that the HTTP request mode is GET.

+http-plain-post[=value], +nohttp-plain-post
Same as +http-plain.

+identify, +noidentify
This option shows [or does not show] the IP address and port number that
supplied the answer, when the +short option is enabled. If short form an‐
swers are requested, the default is not to show the source address and
port number of the server that provided the answer.

+idnin, +noidnin
This option processes [or does 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 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.

+idnout, +noidnout
This option converts [or does not convert] puny code on output. This re‐
quires IDN SUPPORT to have been enabled at compile time.

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.

+ignore, +noignore
This option ignores [or does not ignore] truncation in UDP responses in‐
stead of retrying with TCP. By default, TCP retries are performed.

+keepalive, +nokeepalive
This option sends [or does not send] an EDNS Keepalive option.

+keepopen, +nokeepopen
This option keeps [or does not keep] the TCP socket open between queries,
and reuses it rather than creating a new TCP socket for each lookup. The
default is +nokeepopen.

+multiline, +nomultiline
This option prints [or does not print] records, like the SOA records, in a
verbose multi-line format with human-readable comments. The default is to
print each record on a single line to facilitate machine parsing of the
dig output.

+ndots=D
This option sets the number of dots (D) that must appear in name for it to
be considered absolute. The default value is that defined using the ndots
statement in /etc/resolv.conf, or 1 if no ndots statement is present.
Names with fewer dots are interpreted as relative names, and are searched
for in the domains listed in the search or domain directive in /etc/re‐
solv.conf if +search is set.

+nsid, +nonsid
When enabled, this option includes an EDNS name server ID request when
sending a query.

+nssearch, +nonssearch
When this option is set, dig attempts to find the authoritative name
servers for the zone containing the name being looked up, and display the
SOA record that each name server has for the zone. Addresses of servers
that did not respond are also printed.

+onesoa, +noonesoa
When enabled, this option prints only one (starting) SOA record when per‐
forming an AXFR. The default is to print both the starting and ending SOA
records.

+opcode=value, +noopcode
When enabled, this option sets (restores) the DNS message opcode to the
specified value. The default value is QUERY (0).

+padding=value
This option pads the size of the query packet using the EDNS Padding op‐
tion to blocks of value bytes. For example, +padding=32 causes a 48-byte
query to be padded to 64 bytes. The default block size is 0, which dis‐
ables padding; the maximum is 512. Values are ordinarily expected to be
powers of two, such as 128; however, this is not mandatory. Responses to
padded queries may also be padded, but only if the query uses TCP or DNS
COOKIE.

+qid=value
This option specifies the query ID to use when sending queries.

+qr, +noqr
This option toggles the display of the query message as it is sent. By de‐
fault, the query is not printed.

+question, +noquestion
This option 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 com‐
ment.

+raflag, +noraflag
This option sets [or does not set] the RA (Recursion Available) bit in the
query. The default is +noraflag. This bit is ignored by the server for
QUERY.

+rdflag, +nordflag
This option is a synonym for +recurse, +norecurse.

+recurse, +norecurse
This option toggles the setting of the RD (recursion desired) bit in the
query. This bit is set by default, which means dig normally sends recur‐
sive queries. Recursion is automatically disabled when the +nssearch or
+trace query option is used.

+retry=T
This option sets the number of times to retry UDP and TCP queries to
server to T instead of the default, 2. Unlike +tries, this does not in‐
clude the initial query.

+rrcomments, +norrcomments
This option toggles 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.

+search, +nosearch
This option uses [or does not use] the search list defined by the search‐
list or domain directive in resolv.conf, if any. The search list is not
used by default.

ndots from resolv.conf (default 1), which may be overridden by +ndots, de‐
termines whether the name is treated as relative and hence whether a
search is eventually performed.

+short, +noshort
This option toggles whether a terse answer is provided. The default is to
print the answer in a verbose form. This option always has a global ef‐
fect; it cannot be set globally and then overridden on a per-lookup basis.

+showbadcookie, +noshowbadcookie
This option toggles whether to show the message containing the BADCOOKIE
rcode before retrying the request or not. The default is to not show the
messages.

+showsearch, +noshowsearch
This option performs [or does not perform] a search showing intermediate
results.

+sigchase, +nosigchase
This feature is now obsolete and has been removed; use delv instead.

+split=W
This option splits long hex- or base64-formatted fields in resource
records into chunks of W characters (where W is rounded up to the nearest
multiple of 4). +nosplit or +split=0 causes fields not to be split at all.
The default is 56 characters, or 44 characters when multiline mode is ac‐
tive.

+stats, +nostats
This option toggles the printing of statistics: when the query was made,
the size of the reply, etc. The default behavior is to print the query
statistics as a comment after each lookup.

+subnet=addr[/prefix-length], +nosubnet
This option sends [or does not send] an EDNS CLIENT-SUBNET option with the
specified IP address or network prefix.

dig +subnet=0.0.0.0/0, or simply dig +subnet=0 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
not be used when resolving this query.

+tcflag, +notcflag
This option sets [or does not set] the TC (TrunCation) bit in the query.
The default is +notcflag. This bit is ignored by the server for QUERY.

+tcp, +notcp
This option indicates whether to use TCP when querying name servers. The
default behavior is to use UDP unless a type any or ixfr=N query is re‐
quested, in which case the default is TCP. AXFR queries always use TCP. To
prevent retry over TCP when TC=1 is returned from a UDP query, use +ig‐
nore.

+timeout=T
This option sets the timeout for a query to T seconds. The default timeout
is 5 seconds. An attempt to set T to less than 1 is silently set to 1.

+tls, +notls
This option indicates whether to use DNS over TLS (DoT) when querying name
servers. When this option is in use, the port number defaults to 853.

+tls-ca[=file-name], +notls-ca
This option enables remote server TLS certificate validation for DNS
transports, relying on TLS. Certificate authorities certificates are
loaded from the specified PEM file (file-name). If the file is not speci‐
fied, the default certificates from the global certificates store are
used.

+tls-certfile=file-name, +tls-keyfile=file-name, +notls-certfile, +notls-keyfile
These options set the state of certificate-based client authentication for
DNS transports, relying on TLS. Both certificate chain file and private
key file are expected to be in PEM format. Both options must be specified
at the same time.

+tls-hostname=hostname, +notls-hostname
This option makes dig use the provided hostname during remote server TLS
certificate verification. Otherwise, the DNS server name is used. This op‐
tion has no effect if +tls-ca is not specified.

+topdown, +notopdown
This feature is related to dig +sigchase, which is obsolete and has been
removed. Use delv instead.

+trace, +notrace
This option toggles tracing of the delegation path from the root name
servers for the name being looked up. Tracing is disabled by default. When
tracing is enabled, dig makes iterative queries to resolve the name being
looked up. It follows referrals from the root servers, showing the answer
from each server that was used to resolve the lookup.

If @server is also specified, it affects only the initial query for the
root zone name servers.

+dnssec is also set when +trace is set, to better emulate the default
queries from a name server.

+tries=T
This option sets the number of times to try UDP and TCP queries to server
to T instead of the default, 3. If T is less than or equal to zero, the
number of tries is silently rounded up to 1.

+trusted-key=####
This option formerly specified trusted keys for use with dig +sigchase.
This feature is now obsolete and has been removed; use delv instead.

+ttlid, +nottlid
This option displays [or does not display] the TTL when printing the
record.

+ttlunits, +nottlunits
This option displays [or does not display] the TTL in friendly human-read‐
able time units of s, m, h, d, and w, representing seconds, minutes,
hours, days, and weeks. This implies +ttlid.

+unknownformat, +nounknownformat
This option prints all RDATA in unknown RR type presentation format (RFC
3597). The default is to print RDATA for known types in the type's pre‐
sentation format.

+vc, +novc
This option uses [or does not use] TCP when querying name servers. This
alternate syntax to +tcp is provided for backwards compatibility. The vc
stands for "virtual circuit."

+yaml, +noyaml
When enabled, this option prints the responses (and, if +qr is in use,
also the outgoing queries) in a detailed YAML format.

+zflag, +nozflag
This option sets [or does not set] the last unassigned DNS header flag in
a DNS query. This flag is off by default.

MULTIPLE QUERIES
The BIND 9 implementation of dig supports specifying multiple queries on the com‐
mand line (in addition to supporting the -f batch file option). Each of those
queries can be supplied with its own set of flags, options, and query options.

In this case, each query argument represents an individual query in the com‐
mand-line syntax described above. Each consists of any of the standard options
and flags, the name to be looked up, an optional query type and class, and any
query options that should be applied to that query.

A global set of query options, 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 +cmd and +short options) can be overridden by a
query-specific set of query options. For example:

dig +qr www.isc.org any -x 127.0.0.1 isc.org ns +noqr

shows how dig can be used from the command line to make three lookups: an ANY
query for www.isc.org, a reverse lookup of 127.0.0.1, and a query for the NS
records of isc.org. A global query option of +qr is applied, so that dig shows
the initial query it made for each lookup. The final query has a local query op‐
tion of +noqr which means that dig does not print the initial query when it looks
up the NS records for isc.org.

IDN SUPPORT
If dig has been built with IDN (internationalized domain name) support, it can
accept and display non-ASCII domain names. dig appropriately converts character
encoding of a domain name before sending a request to a DNS server or displaying
a reply from the server. To turn off IDN support, use the parameters +idnin and
+idnout, or define the IDN_DISABLE environment variable.

RETURN CODES
dig return codes are:

0 DNS response received, including NXDOMAIN status

1 Usage error

8 Couldn't open batch file

9 No reply from server

10 Internal error

FILES
/etc/resolv.conf

${HOME}/.digrc

SEE ALSO
delv(1), host(1), named(8), dnssec-keygen(8), RFC 1035.

BUGS
There are probably too many query options.

AUTHOR
Internet Systems Consortium

9.18.39-0ubuntu0.24.04.9-Ubuntu 2025-08-13 DIG(1)

Generated 2026-11-03 from dig.1 in the official Ubuntu 24.04 package bind9-dnsutils 1:9.18.39-0ubuntu0.24.04.9. Extracted without installing the package. Original copyright and license terms apply.