NAME¶
mdig - DNS pipelined lookup utility
SYNOPSIS¶
mdig {@server} [-f filename]
[-h] [-v] [[-4] | [-6]] [-m]
[-b address]
[-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
received, 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 retrieved from /etc/resolv.conf.) It can be an IPv4 address in
dotted-decimal notation, an IPv6 address in colon-delimited notation, or a
hostname. When the supplied server argument is a hostname,
mdig resolves 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
answer get printed, and others determine 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.
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 organized 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 options 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 default 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 format 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 answer 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 example, 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 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 active.
+[no]tcp
Use [do not use] TCP when querying name servers. The
default behavior 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, minutes, 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", unless the -x option is supplied to indicate a reverse
lookup with the "PTR" query type.
The -i option sets the reverse domain for IPv6 addresses to
IP6.INT.
Reverse lookups — mapping addresses to names — 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. To use the older RFC1886 method using the IP6.INT
domain specify the -i option.
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
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.
+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
responses.
+[no]cookie[=####]
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 +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 options 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 instead 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
specified 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 being
applied.
+tries=T
Sets the number of times to try UDP 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.
+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]zflag
Set [do not set] the last unassigned DNS header flag in a
DNS query. This flag is off by default.
AUTHOR¶
Internet Systems Consortium, Inc.
COPYRIGHT¶
Copyright © 2015-2018 Internet Systems Consortium, Inc.
("ISC")