dig - 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 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.

 +[no]tcp
     Use [do not use] TCP when querying name servers. The default
     behavior is to use UDP unless an AXFR or IXFR query is requested,
     in which case a TCP connection is used.

 +[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".

 +[no]ignore
     Ignore truncation in UDP responses instead of retrying with TCP. By
     default, TCP retries are performed.

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

 +[no]search
     Use [do not use] the search list defined by the searchlist or
     domain directive in resolv.conf (if any). The search list is not
     used by default.

 +[no]showsearch
     Perform [do not perform] a search showing intermediate results.

 +[no]defname
     Deprecated, treated as a synonym for +[no]search

 +[no]aaonly
     Sets the "aa" flag in the query.

 +[no]aaflag
     A synonym for +[no]aaonly.

 +[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.

 +[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]cl
     Display [do not display] the CLASS when printing the record.

 +[no]ttlid
     Display [do not display] the TTL when printing the record.

 +[no]recurse
     Toggle the setting of the RD (recursion desired) bit in the query.
     This bit is set by default, which means dig normally sends
     recursive queries. Recursion is automatically disabled when the
     +nssearch or +trace query options are used.

 +[no]nssearch
     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.

 +[no]trace
     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, dig 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.

 +[no]cmd
     Toggles the printing of the initial comment in the output
     identifying the version of dig and the query options that have been
     applied. This comment is printed by default.

 +[no]short
     Provide a terse answer. The default is to print the answer in a
     verbose form.

 +[no]identify
     Show [or do not show] the IP address and port number that supplied
     the answer when the +short 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.

 +[no]comments
     Toggle the display of comment lines in the output. The default is
     to print comments.

 +[no]stats
     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.

 +[no]qr
     Print [do not print] the query as it is sent. By default, the query
     is not printed.

 +[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]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]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.

 +time=T
     Sets the timeout for a query to T seconds. The default timeout is 5
     seconds. 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.

 +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.

 +ndots=D
     Set the number of dots that have to appear in name to D 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 will be searched for in the domains listed in the search or
     domain directive in /etc/resolv.conf.

 +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.

 +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.

 +[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 dig output.

 +[no]fail
     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.

 +[no]besteffort
     Attempt to display the contents of messages which are malformed.
     The default is to not display malformed answers.

 +[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]sigchase
     Chase DNSSEC signature chains. Requires dig be compiled with
     -DDIG_SIGCHASE.

 +trusted-key=####
     Specifies a file containing trusted keys to be used with +sigchase.
     Each DNSKEY record must be on its own line.

     If not specified, dig will look for /etc/trusted-key.key then
     trusted-key.key in the current directory.

     Requires dig be compiled with -DDIG_SIGCHASE.

 +[no]topdown
     When chasing DNSSEC signature chains perform a top-down validation.
     Requires dig be compiled with -DDIG_SIGCHASE.

 +[no]nsid
     Include an EDNS name server ID request when sending a query.

"A prediction is worth twenty explanations" - K. Brecher

Related:

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