.. highlight:: none ``kdig`` – Advanced DNS lookup utility ====================================== Synopsis -------- :program:`kdig` [*common-settings*] [*query* [*settings*]]... :program:`kdig` **-h** Description ----------- This utility sends one or more DNS queries to a nameserver. Each query can have individual *settings*, or it can be specified globally via *common-settings*, which must precede *query* specification. Parameters .......... *query* *name* | **-q** *name* | **-x** *address* | **-G** *tapfile* *common-settings*, *settings* [*query_class*] [*query_type*] [**@**\ *server*]... [*options*] *name* Is a domain name that is to be looked up. *server* Is a domain name or an IPv4 or IPv6 address of the nameserver to send a query to. An additional port can be specified using address:port ([address]:port for IPv6 address), address@port, or address#port notation. A value which begins with '/' character is considered an absolute UNIX socket path. If no server is specified, the servers from :file:`/etc/resolv.conf` are used. If no arguments are provided, :program:`kdig` sends NS query for the root zone. Query classes ............. A *query_class* can be either a DNS class name (IN, CH) or generic class specification **CLASS**\ *XXXXX* where *XXXXX* is a corresponding decimal class number. The default query class is IN. Query types ........... A *query_type* can be either a DNS resource record type (A, AAAA, NS, SOA, DNSKEY, ANY, etc.) or one of the following: **TYPE**\ *XXXXX* Generic query type specification where *XXXXX* is a corresponding decimal type number. **AXFR** Full zone transfer request. **IXFR=**\ *serial* Incremental zone transfer request for specified SOA serial number (i.e. all zone updates since the specified zone version are to be returned). **NOTIFY=**\ *serial* Notify message with a SOA serial hint specified. **NOTIFY** Notify message with a SOA serial hint unspecified. The default query type is A. Options ....... **-4** Use the IPv4 protocol only. **-6** Use the IPv6 protocol only. **-b** *address* Set the source IP address of the query to *address*. The address must be a valid address for local interface or :: or 0.0.0.0. An optional port can be specified in the same format as the *server* value. **-c** *class* An explicit *query_class* specification. See possible values above. **-d** Enable debug messages. **-h**, **--help** Print the program help. **-k** *keyfile* Use the TSIG key stored in a file *keyfile* to authenticate the request. The file must contain the key in the same format as accepted by the **-y** option. **-p** *port* Set the nameserver port number or service name to send a query to. The default port is 53. **-q** *name* Set the query name. An explicit variant of *name* specification. If no *name* is provided, empty question section is set. **-t** *type* An explicit *query_type* specification. See possible values above. **-V**, **--version** Print the program version. **-x** *address* Send a reverse (PTR) query for IPv4 or IPv6 *address*. The correct name, class and type is set automatically. **-y** [*alg*:]\ *name*:*key* Use the TSIG key named *name* to authenticate the request. The *alg* part specifies the algorithm (the default is hmac-sha256) and *key* specifies the shared secret encoded in Base64. **-E** *tapfile* Export a dnstap trace of the query and response messages received to the file *tapfile*. **-G** *tapfile* Generate message output from a previously saved dnstap file *tapfile*. **+**\ [\ **no**\ ]\ **multiline** Wrap long records to more lines and improve human readability. **+**\ [\ **no**\ ]\ **short** Show record data only. **+**\ [\ **no**\ ]\ **generic** Use the generic representation format when printing resource record types and data. **+**\ [\ **no**\ ]\ **crypto** Display the DNSSEC keys and signatures values in base64, instead of omitting them. **+**\ [\ **no**\ ]\ **aaflag** Set the AA flag. **+**\ [\ **no**\ ]\ **tcflag** Set the TC flag. **+**\ [\ **no**\ ]\ **rdflag** Set the RD flag. **+**\ [\ **no**\ ]\ **recurse** Same as **+**\ [\ **no**\ ]\ **rdflag** **+**\ [\ **no**\ ]\ **raflag** Set the RA flag. **+**\ [\ **no**\ ]\ **zflag** Set the zero flag bit. **+**\ [\ **no**\ ]\ **adflag** Set the AD flag. **+**\ [\ **no**\ ]\ **cdflag** Set the CD flag. **+**\ [\ **no**\ ]\ **dnssec** Set the DO flag. **+**\ [\ **no**\ ]\ **all** Show all packet sections. **+**\ [\ **no**\ ]\ **qr** Show the query packet. **+**\ [\ **no**\ ]\ **header** Show the packet header. **+**\ [\ **no**\ ]\ **comments** Show commented section names. **+**\ [\ **no**\ ]\ **opt** Show the EDNS pseudosection. **+**\ [\ **no**\ ]\ **opttext** Try to show unknown EDNS options as text. **+**\ [\ **no**\ ]\ **optpresent** Show EDNS in presentation format according to the specification in version `draft-peltan-edns-presentation-format-01 `_. **+**\ [\ **no**\ ]\ **question** Show the question section. **+**\ [\ **no**\ ]\ **answer** Show the answer section. **+**\ [\ **no**\ ]\ **authority** Show the authority section. **+**\ [\ **no**\ ]\ **additional** Show the additional section. **+**\ [\ **no**\ ]\ **tsig** Show the TSIG pseudosection. **+**\ [\ **no**\ ]\ **stats** Show trailing packet statistics. **+**\ [\ **no**\ ]\ **class** Show the DNS class. **+**\ [\ **no**\ ]\ **ttl** Show the TTL value. **+**\ [\ **no**\ ]\ **tcp** Use the TCP protocol (default is UDP for standard query and TCP for AXFR/IXFR). **+**\ [\ **no**\ ]\ **fastopen** Use TCP Fast Open. **+**\ [\ **no**\ ]\ **ignore** Don't use TCP automatically if a truncated reply is received. **+**\ [\ **no**\ ]\ **keepopen** Keep TCP connection open for the following query if it has the same connection configuration. This applies to +tcp, +tls, and +https operations. The connection is considered in the context of a single kdig call only. **+**\ [\ **no**\ ]\ **tls** Use TLS with the Opportunistic privacy profile (:rfc:`7858#section-4.1`). **+**\ [\ **no**\ ]\ **tls-ca**\[\ =\ *FILE*\] Use TLS with a certificate validation. Certification authority certificates are loaded from the specified PEM file (default is system certificate storage if no argument is provided). Can be specified multiple times. If the +tls-hostname option is not provided, the name of the target server (if specified) is used for strict authentication. **+**\ [\ **no**\ ]\ **tls-pin**\ =\ *BASE64* Use TLS with the Out-of-Band key-pinned privacy profile (:rfc:`7858#section-4.2`). The PIN must be a Base64 encoded SHA-256 hash of the X.509 SubjectPublicKeyInfo. Can be specified multiple times. **+**\ [\ **no**\ ]\ **tls-hostname**\ =\ *STR* Use TLS with a remote server hostname check. **+**\ [\ **no**\ ]\ **tls-sni**\ =\ *STR* Use TLS with a Server Name Indication. **+**\ [\ **no**\ ]\ **tls-keyfile**\ =\ *FILE* Use TLS with a client keyfile. **+**\ [\ **no**\ ]\ **tls-certfile**\ =\ *FILE* Use TLS with a client certfile. **+**\ [\ **no**\ ]\ **tls-ocsp-stapling**\[\ =\ *H*\] Use TLS with a valid stapled OCSP response for the server certificate (%u or specify hours). OCSP responses older than the specified period are considered invalid. **+**\ [\ **no**\ ]\ **https**\[\ =\ *URL*\] Use HTTPS (DNS-over-HTTPS) in wire format (:rfc:`1035#section-4.2.1`). It is also possible to specify URL=\[authority\]\[/path\] where request will be sent to. Any leading scheme and authority indicator (i.e. //) are ignored. Authority might also be specified as the *server* (using the parameter `@`). If *path* is specified and *authority* is missing, then the *server* is used as authority together with the specified *path*. Library *libnghttp2* is required. **+**\ [\ **no**\ ]\ **https-get** Use HTTPS with HTTP/GET method instead of the default HTTP/POST method. Library *libnghttp2* is required. **+**\ [\ **no**\ ]\ **quic** Use QUIC (DNS-over-QUIC). **+**\ [\ **no**\ ]\ **nsid** Request the nameserver identifier (NSID). **+**\ [\ **no**\ ]\ **bufsize**\ =\ *B* Set EDNS buffer size in bytes (default is 4096 bytes). **+**\ [\ **no**\ ]\ **padding**\[\ =\ *B*\] Use EDNS(0) padding option to pad queries, optionally to a specific size. The default is to pad queries with a sensible amount when using +tls, and not to pad at all when queries are sent without TLS. With no argument (i.e., just +padding) pad every query with a sensible amount regardless of the use of TLS. With +nopadding, never pad. **+**\ [\ **no**\ ]\ **alignment**\[\ =\ *B*\] Align the query to B\-byte-block message using the EDNS(0) padding option (default is no or 128 if no argument is specified). **+**\ [\ **no**\ ]\ **subnet**\ =\ *SUBN* Set EDNS(0) client subnet SUBN=addr/prefix. **+**\ [\ **no**\ ]\ **edns**\[\ =\ *N*\] Use EDNS version (default is 0). **+**\ [\ **no**\ ]\ **timeout**\ =\ *T* Set the wait-for-reply interval in seconds (default is 5 seconds). This timeout applies to each query attempt. Zero value or *notimeout* is interpreted as infinity. **+**\ [\ **no**\ ]\ **retry**\ =\ *N* Set the number (>=0) of UDP retries (default is 2). This doesn't apply to AXFR/IXFR. **+**\ [\ **no**\ ]\ **expire** Sets the EXPIRE EDNS option. **+**\ [\ **no**\ ]\ **cookie**\[\ =\ *HEX*\] Attach EDNS(0) cookie to the query. **+**\ [\ **no**\ ]\ **badcookie** Repeat a query with the correct cookie. **+**\ [\ **no**\ ]\ **ednsopt**\[\ =\ *CODE*\[:*HEX*\]\] Send custom EDNS option. The *CODE* is EDNS option code in decimal, *HEX* is an optional hex encoded string to use as EDNS option value. This argument can be used multiple times. +noednsopt clears all EDNS options specified by +ednsopt. **+**\ [\ **no**\ ]\ **proxy**\ =\ *SRC_ADDR*\[#\ *SRC_PORT*\]-*DST_ADDR*\[#\ *DST_PORT*\] Add PROXYv2 header with the specified source and destination addresses to the query. The default source port is 0 and destination port 53. **+**\ [\ **no**\ ]\ **json** Use JSON for output encoding (RFC 8427). **+noidn** Disable the IDN transformation to ASCII and vice versa. IDN support depends on libidn availability during project building! If used in *common-settings*, all IDN transformations are disabled. If used in the individual query *settings*, transformation from ASCII is disabled on output for the particular query. Note that IDN transformation does not preserve domain name letter case. Notes ----- Options **-k** and **-y** can not be used simultaneously. Dnssec-keygen keyfile format is not supported. Use :manpage:`keymgr(8)` instead. Exit values ----------- Exit status of 0 means successful operation. Any other exit status indicates an error. Examples -------- 1. Get A records for example.com:: $ kdig example.com A 2. Perform AXFR for zone example.com from the server 192.0.2.1:: $ kdig example.com -t AXFR @192.0.2.1 3. Get A records for example.com from 192.0.2.1 and reverse lookup for address 2001:DB8::1 from 192.0.2.2. Both using the TCP protocol:: $ kdig +tcp example.com -t A @192.0.2.1 -x 2001:DB8::1 @192.0.2.2 4. Get SOA record for example.com, use TLS, use system certificates, check for specified hostname, check for certificate pin, and print additional debug info:: $ kdig -d @185.49.141.38 +tls-ca +tls-host=getdnsapi.net \ +tls-pin=foxZRnIh9gZpWnl+zEiKa0EJ2rdCGroMWm02gaxSc9S= soa example.com 5. DNS over HTTPS examples (various DoH implementations):: $ kdig @1.1.1.1 +https example.com. $ kdig @193.17.47.1 +https=/doh example.com. $ kdig @8.8.4.4 +https +https-get example.com. $ kdig @8.8.8.8 +https +tls-hostname=dns.google +fastopen example.com. 6. More queries share one DoT connection:: $ kdig @1.1.1.1 +tls +keepopen abc.example.com A mail.example.com AAAA Files ----- :file:`/etc/resolv.conf` See Also -------- :manpage:`khost(1)`, :manpage:`knsupdate(1)`, :manpage:`keymgr(8)`.