1KDIG(1) Knot DNS KDIG(1)
2
6 kdig - Advanced DNS lookup utility
7
9 kdig [common-settings] [query [settings]]...
10 kdig -h
12
14 This utility sends one or more DNS queries to a nameserver. Each query
15 can have individual settings, or it can be specified globally via com‐
16 mon-settings, which must precede query specification.
17 Parameters
19 query name | -q name | -x address | -G tapfile
20 common-settings, settings
22 [query_class] [query_type] [@server]... [options]
23 name Is a domain name that is to be looked up.
25 server Is a domain name or an IPv4 or IPv6 address of the nameserver to
27 send a query to. An additional port can be specified using ad‐
28 dress:port ([address]:port for IPv6 address), address@port, or
29 address#port notation. If no server is specified, the servers
30 from /etc/resolv.conf are used.
31 If no arguments are provided, kdig sends NS query for the root zone.
33 Query classes
35 A query_class can be either a DNS class name (IN, CH) or generic class
36 specification CLASSXXXXX where XXXXX is a corresponding decimal class
37 number. The default query class is IN.
38 Query types
40 A query_type can be either a DNS resource record type (A, AAAA, NS,
41 SOA, DNSKEY, ANY, etc.) or one of the following:
42 TYPEXXXXX
44 Generic query type specification where XXXXX is a corresponding
45 decimal type number.
46 AXFR Full zone transfer request.
48 IXFR=serial
50 Incremental zone transfer request for specified SOA serial num‐
51 ber (i.e. all zone updates since the specified zone version are
52 to be returned).
53 NOTIFY=serial
55 Notify message with a SOA serial hint specified.
56 NOTIFY Notify message with a SOA serial hint unspecified.
58 The default query type is A.
60 Options
62 -4 Use the IPv4 protocol only.
63 -6 Use the IPv6 protocol only.
65 -b address
67 Set the source IP address of the query to address. The address
68 must be a valid address for local interface or :: or 0.0.0.0. An
69 optional port can be specified in the same format as the server
70 value.
71 -c class
73 An explicit query_class specification. See possible values
74 above.
75 -d Enable debug messages.
77 -h, --help
79 Print the program help.
80 -k keyfile
82 Use the TSIG key stored in a file keyfile to authenticate the
83 request. The file must contain the key in the same format as ac‐
84 cepted by the -y option.
85 -p port
87 Set the nameserver port number or service name to send a query
88 to. The default port is 53.
89 -q name
91 Set the query name. An explicit variant of name specification.
92 If no name is provided, empty question section is set.
93 -t type
95 An explicit query_type specification. See possible values above.
96 -V, --version
98 Print the program version.
99 -x address
101 Send a reverse (PTR) query for IPv4 or IPv6 address. The correct
102 name, class and type is set automatically.
103 -y [alg:]name:key
105 Use the TSIG key named name to authenticate the request. The alg
106 part specifies the algorithm (the default is hmac-sha256) and
107 key specifies the shared secret encoded in Base64.
108 -E tapfile
110 Export a dnstap trace of the query and response messages re‐
111 ceived to the file tapfile.
112 -G tapfile
114 Generate message output from a previously saved dnstap file tap‐
115 file.
116 +[no]multiline
118 Wrap long records to more lines and improve human readability.
119 +[no]short
121 Show record data only.
122 +[no]generic
124 Use the generic representation format when printing resource
125 record types and data.
126 +[no]crypto
128 Display the DNSSEC keys and signatures values in base64, instead
129 of omitting them.
130 +[no]aaflag
132 Set the AA flag.
133 +[no]tcflag
135 Set the TC flag.
136 +[no]rdflag
138 Set the RD flag.
139 +[no]recurse
141 Same as +[no]rdflag
142 +[no]raflag
144 Set the RA flag.
145 +[no]zflag
147 Set the zero flag bit.
148 +[no]adflag
150 Set the AD flag.
151 +[no]cdflag
153 Set the CD flag.
154 +[no]dnssec
156 Set the DO flag.
157 +[no]all
159 Show all packet sections.
160 +[no]qr
162 Show the query packet.
163 +[no]header
165 Show the packet header.
166 +[no]comments
168 Show commented section names.
169 +[no]opt
171 Show the EDNS pseudosection.
172 +[no]opttext
174 Try to show unknown EDNS options as text.
175 +[no]question
177 Show the question section.
178 +[no]answer
180 Show the answer section.
181 +[no]authority
183 Show the authority section.
184 +[no]additional
186 Show the additional section.
187 +[no]tsig
189 Show the TSIG pseudosection.
190 +[no]stats
192 Show trailing packet statistics.
193 +[no]class
195 Show the DNS class.
196 +[no]ttl
198 Show the TTL value.
199 +[no]tcp
201 Use the TCP protocol (default is UDP for standard query and TCP
202 for AXFR/IXFR).
203 +[no]fastopen
205 Use TCP Fast Open (default with TCP).
206 +[no]ignore
208 Don't use TCP automatically if a truncated reply is received.
209 +[no]tls
211 Use TLS with the Opportunistic privacy profile (RFC 7858#sec‐
212 tion-4.1).
213 +[no]tls-ca[=FILE]
215 Use TLS with a certificate validation. Certification authority
216 certificates are loaded from the specified PEM file (default is
217 system certificate storage if no argument is provided). Can be
218 specified multiple times. If the +tls-hostname option is not
219 provided, the name of the target server (if specified) is used
220 for strict authentication.
221 +[no]tls-pin=BASE64
223 Use TLS with the Out-of-Band key-pinned privacy profile (RFC
224 7858#section-4.2). The PIN must be a Base64 encoded SHA-256
225 hash of the X.509 SubjectPublicKeyInfo. Can be specified multi‐
226 ple times.
227 +[no]tls-hostname=STR
229 Use TLS with a remote server hostname check.
230 +[no]tls-sni=STR
232 Use TLS with a Server Name Indication.
233 +[no]tls-keyfile=FILE
235 Use TLS with a client keyfile.
236 +[no]tls-certfile=FILE
238 Use TLS with a client certfile.
239 +[no]tls-ocsp-stapling[=H]
241 Use TLS with a valid stapled OCSP response for the server cer‐
242 tificate (%u or specify hours). OCSP responses older than the
243 specified period are considered invalid.
244 +[no]https[=URL]
246 Use HTTPS (DNS-over-HTTPS) in wire format (RFC 1035#sec‐
247 tion-4.2.1). It is also possible to specify URL=[author‐
248 ity][/path] where request will be send. Authority might also be
249 specified as server name (parameter @). Library libnghttp2 is
250 required.
251 +[no]https-get
253 Use HTTPS with HTTP/GET method instead of the default HTTP/POST
254 method. Library libnghttp2 is required.
255 +[no]nsid
257 Request the nameserver identifier (NSID).
258 +[no]bufsize=B
260 Set EDNS buffer size in bytes (default is 512 bytes).
261 +[no]padding[=B]
263 Use EDNS(0) padding option to pad queries, optionally to a spe‐
264 cific size. The default is to pad queries with a sensible amount
265 when using +tls, and not to pad at all when queries are sent
266 without TLS. With no argument (i.e., just +padding) pad every
267 query with a sensible amount regardless of the use of TLS. With
268 +nopadding, never pad.
269 +[no]alignment[=B]
271 Align the query to B-byte-block message using the EDNS(0) pad‐
272 ding option (default is no or 128 if no argument is specified).
273 +[no]subnet=SUBN
275 Set EDNS(0) client subnet SUBN=addr/prefix.
276 +[no]edns[=N]
278 Use EDNS version (default is 0).
279 +[no]timeout=T
281 Set the wait-for-reply interval in seconds (default is 5 sec‐
282 onds). This timeout applies to each query attempt. An attempt to
283 set T to less than 1 will result in a query timeout of 1 second
284 being applied.
285 +[no]retry=N
287 Set the number (>=0) of UDP retries (default is 2). This doesn't
288 apply to AXFR/IXFR.
289 +[no]cookie=HEX
291 Attach EDNS(0) cookie to the query.
292 +[no]badcookie
294 Repeat a query with the correct cookie.
295 +[no]ednsopt[=CODE[:HEX]]
297 Send custom EDNS option. The CODE is EDNS option code in deci‐
298 mal, HEX is an optional hex encoded string to use as EDNS option
299 value. This argument can be used multiple times. +noednsopt
300 clears all EDNS options specified by +ednsopt.
301 +noidn Disable the IDN transformation to ASCII and vice versa. IDN sup‐
303 port depends on libidn availability during project building! If
304 used in common-settings, all IDN transformations are disabled.
305 If used in the individual query settings, transformation from
306 ASCII is disabled on output for the particular query. Note that
307 IDN transformation does not preserve domain name letter case.
308
310 Options -k and -y can not be used simultaneously.
311 Dnssec-keygen keyfile format is not supported. Use keymgr(8) instead.
313
315 Exit status of 0 means successful operation. Any other exit status in‐
316 dicates an error.
317
319 1. Get A records for example.com:
320 $ kdig example.com A
322 2. Perform AXFR for zone example.com from the server 192.0.2.1:
324 $ kdig example.com -t AXFR @192.0.2.1
326 3. Get A records for example.com from 192.0.2.1 and reverse lookup for
328 address 2001:DB8::1 from 192.0.2.2. Both using the TCP protocol:
329 $ kdig +tcp example.com -t A @192.0.2.1 -x 2001:DB8::1 @192.0.2.2
331 4. Get SOA record for example.com, use TLS, use system certificates,
333 check for specified hostname, check for certificate pin, and print
334 additional debug info:
335 $ kdig -d @185.49.141.38 +tls-ca +tls-host=getdnsapi.net \
337 +tls-pin=foxZRnIh9gZpWnl+zEiKa0EJ2rdCGroMWm02gaxSc9S= soa example.com
338 5. DNS over HTTPS examples (various DoH implementations):
340 $ kdig @1.1.1.1 +https example.com.
342 $ kdig @193.17.47.1 +https=/doh example.com.
343 $ kdig @8.8.4.4 +https +https-get example.com.
344
346 /etc/resolv.conf
347
349 khost(1), knsupdate(1), keymgr(8).
350
352 CZ.NIC Labs <https://www.knot-dns.cz>
353
355 Copyright 2010–2021, CZ.NIC, z.s.p.o.
3563.0.6 2021-05-12 KDIG(1)