MDIG(1) BIND 9 MDIG(1)
NAME
mdig - DNS pipelined lookup utility
SYNOPSIS
mdig {@server} [-f filename] [-h] [-v] [ [-4] | [-6] ] [-m] [-b ad-
dress] [-p port#] [-c class] [-t type] [-i] [-x addr] [plusopt...]
mdig {-h}
mdig [@server] {global-opt...} { {local-opt...} {query} ...}
DESCRIPTION
mdig is a multiple/pipelined query version of dig: instead of waiting
for a response after sending each query, it begins by sending all
queries. Responses are displayed in the order in which they are re-
ceived, not in the order the corresponding queries were sent.
mdig options are a subset of the dig options, and are divided into
"anywhere options" which can occur anywhere, "global options" which
must occur before the query name (or they are ignored with a warning),
and "local options" which apply to the next query on the command line.
The @server option is a mandatory global option. It is the name or IP
address of the name server to query. (Unlike dig, this value is not re-
trieved from /etc/resolv.conf.) It can be an IPv4 address in dot-
ted-decimal notation, an IPv6 address in colon-delimited notation, or a
hostname. When the supplied server argument is a hostname, mdig re-
solves that name before querying the name server.
mdig 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 an-
swer get printed, and others determine the timeout and retry strate-
gies.
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 +key-
word=value.
ANYWHERE OPTIONS
The -f option makes mdig operate in batch mode by reading a list of
lookup requests to process from the file filename. The file contains a
number of queries, one per line. Each entry in the file should be orga-
nized in the same way they would be presented as queries to mdig using
the command-line interface.
The -h causes mdig to print the detailed help with the full list of op-
tions and exit.
The -v causes mdig to print the version number and exit.
GLOBAL OPTIONS
The -4 option forces mdig to only use IPv4 query transport.
The -6 option forces mdig to only use IPv6 query transport.
The -b option sets the source IP address of the query to address. This
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>"
The -m option enables memory usage debugging.
The -p option is used when a non-standard port number is to be queried.
port# is the port number that mdig will send its queries instead of the
standard DNS port number 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.
The global query options are:
+[no]additional
Display [do not display] the additional section of a reply. The
default is to display it.
+[no]all
Set or clear all display flags.
+[no]answer
Display [do not display] the answer section of a reply. The de-
fault is to display it.
+[no]authority
Display [do not display] the authority section of a reply. The
default is to display it.
+[no]besteffort
Attempt to display the contents of messages which are malformed.
The default is to not display malformed answers.
+[no]cl
Display [do not display] the CLASS when printing the record.
+[no]comments
Toggle the display of comment lines in the output. The default
is to print comments.
+[no]continue
Continue on errors (e.g. timeouts).
+[no]crypto
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 ]".
+dscp[=value]
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.
+[no]multiline
Print records like the SOA records in a verbose multi-line for-
mat with human-readable comments. The default is to print each
record on a single line, to facilitate machine parsing of the
mdig output.
+[no]question
Print [do not print] the question section of a query when an an-
swer is returned. The default is to print the question section
as a comment.
+[no]rrcomments
Toggle the display of per-record comments in the output (for ex-
ample, human-readable key information about DNSKEY records). The
default is not to print record comments unless multiline mode is
active.
+[no]short
Provide a terse answer. The default is to print the answer in a
verbose form.
+split=W
Split long hex- or base64-formatted fields in resource records
into chunks of W characters (where W is rounded up to the near-
est 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 active.
+[no]tcp
Use [do not use] TCP when querying name servers. The default be-
havior is to use UDP.
+[no]ttlid
Display [do not display] the TTL when printing the record.
+[no]ttlunits
Display [do not display] the TTL in friendly human-readable time
units of "s", "m", "h", "d", and "w", representing seconds, min-
utes, hours, days and weeks. Implies +ttlid.
+[no]vc
Use [do not use] TCP when querying name servers. This alternate
syntax to +[no]tcp is provided for backwards compatibility. The
"vc" stands for "virtual circuit".
LOCAL OPTIONS
The -c option sets the query class to class. It can be any valid query
class which is supported in BIND 9. The default query class is "IN".
The -t option sets the query type to type. It can be any valid query
type which is supported in BIND 9. The default query type is "A", un-
less the -x option is supplied to indicate a reverse lookup with the
"PTR" query type.
Reverse lookups MDASH mapping addresses to names MDASH are simplified
by the -x option. addr is an IPv4 address in dotted-decimal notation,
or a colon-delimited IPv6 address. mdig automatically performs a lookup
for a query name like 11.12.13.10.in-addr.arpa and sets the query type
and class to PTR and IN respectively. By default, IPv6 addresses are
looked up using nibble format under the IP6.ARPA domain.
The local query options are:
+[no]aaflag
A synonym for +[no]aaonly.
+[no]aaonly
Sets the "aa" flag in the query.
+[no]adflag
Set [do not set] the AD (authentic data) bit in the query. This
requests the server to return whether all of the answer and au-
thority 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.
+bufsize=B
Set the UDP message buffer size advertised using EDNS0 to B
bytes. The maximum and minimum sizes of this buffer are 65535
and 0 respectively. Values outside this range are rounded up or
down appropriately. Values other than zero will cause a EDNS
query to be sent.
+[no]cdflag
Set [do not set] the CD (checking disabled) bit in the query.
This requests the server to not perform DNSSEC validation of re-
sponses.
+[no]cookie=####
Send a COOKIE EDNS option, with optional value. Replaying a
COOKIE from a previous response will allow the server to iden-
tify a previous client. The default is +nocookie.
+[no]dnssec
Requests DNSSEC records be sent by setting the DNSSEC OK bit
(DO) in the OPT record in the additional section of the query.
+[no]edns[=#]
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. +noedns clears the remembered EDNS version. EDNS is set
to 0 by default.
+[no]ednsflags[=#]
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.
+[no]ednsopt[=code[:value]]
Specify EDNS option with code point code and optionally payload
of value as a hexadecimal string. +noednsopt clears the EDNS op-
tions to be sent.
+[no]expire
Send an EDNS Expire option.
+[no]nsid
Include an EDNS name server ID request when sending a query.
+[no]recurse
Toggle the setting of the RD (recursion desired) bit in the
query. This bit is set by default, which means mdig normally
sends recursive queries.
+retry=T
Sets the number of times to retry UDP queries to server to T in-
stead of the default, 2. Unlike +tries, this does not include
the initial query.
+[no]subnet=addr[/prefix-length]
Send (don't send) an EDNS Client Subnet option with the speci-
fied IP address or network prefix.
mdig +subnet=0.0.0.0/0, or simply mdig +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.
+timeout=T
Sets the timeout for a query to T seconds. The default timeout
is 5 seconds for UDP transport and 10 for TCP. An attempt to set
T to less than 1 will result in a query timeout of 1 second be-
ing applied.
+tries=T
Sets the number of times to try UDP queries to server to T in-
stead of the default, 3. If T is less than or equal to zero, the
number of tries is silently rounded up to 1.
+udptimeout=T
Sets the timeout between UDP query retries.
+[no]unknownformat
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.
+[no]yaml
Print the responses in a detailed YAML format.
+[no]zflag
Set [do not set] the last unassigned DNS header flag in a DNS
query. This flag is off by default.
SEE ALSO
dig(1), RFC 1035.
AUTHOR
Internet Systems Consortium
COPYRIGHT
2020, Internet Systems Consortium
9.16.8-Debian 2020-10-13 MDIG(1)