1RESOLVECTL(1)                     resolvectl                     RESOLVECTL(1)
2
3
4

NAME

6       resolvectl, resolvconf - Resolve domain names, IPV4 and IPv6 addresses,
7       DNS resource records, and services; introspect and reconfigure the DNS
8       resolver
9

SYNOPSIS

11       resolvectl [OPTIONS...] {COMMAND} [NAME...]
12

DESCRIPTION

14       resolvectl may be used to resolve domain names, IPv4 and IPv6
15       addresses, DNS resource records and services with the systemd-
16       resolved.service(8) resolver service. By default, the specified list of
17       parameters will be resolved as hostnames, retrieving their IPv4 and
18       IPv6 addresses. If the parameters specified are formatted as IPv4 or
19       IPv6 addresses the reverse operation is done, and a hostname is
20       retrieved for the specified addresses.
21
22       The program's output contains information about the protocol used for
23       the look-up and on which network interface the data was discovered. It
24       also contains information on whether the information could be
25       authenticated. All data for which local DNSSEC validation succeeds is
26       considered authenticated. Moreover all data originating from local,
27       trusted sources is also reported authenticated, including resolution of
28       the local host name, the "localhost" hostname or all data from
29       /etc/hosts.
30

COMMANDS

32       query HOSTNAME|ADDRESS...
33           Resolve domain names, as well as IPv4 and IPv6 addresses. When used
34           in conjunction with --type= or --class= (see below), resolves
35           low-level DNS resource records.
36
37           If a single-label domain name is specified it is searched for
38           according to the configured search domains — unless --search=no or
39           --type=/--class= are specified, both of which turn this logic off.
40
41           If an international domain name is specified, it is automatically
42           translated according to IDNA rules when resolved via classic DNS —
43           but not for look-ups via MulticastDNS or LLMNR. If --type=/--class=
44           is used IDNA translation is turned off and domain names are
45           processed as specified.
46
47       service [[NAME] TYPE] DOMAIN
48           Resolve DNS-SD[1] and SRV[2] services, depending on the specified
49           list of parameters. If three parameters are passed the first is
50           assumed to be the DNS-SD service name, the second the SRV service
51           type, and the third the domain to search in. In this case a full
52           DNS-SD style SRV and TXT lookup is executed. If only two parameters
53           are specified, the first is assumed to be the SRV service type, and
54           the second the domain to look in. In this case no TXT resource
55           record is requested. Finally, if only one parameter is specified,
56           it is assumed to be a domain name, that is already prefixed with an
57           SRV type, and an SRV lookup is done (no TXT).
58
59       openpgp EMAIL@DOMAIN...
60           Query PGP keys stored as OPENPGPKEY resource records, see RFC
61           7929[3]. Specified e-mail addresses are converted to the
62           corresponding DNS domain name, and any OPENPGPKEY keys are printed.
63
64       tlsa [FAMILY] DOMAIN[:PORT]...
65           Query TLS public keys stored as TLSA resource records, see RFC
66           6698[4]. A query will be performed for each of the specified names
67           prefixed with the port and family ("_port._family.domain"). The
68           port number may be specified after a colon (":"), otherwise 443
69           will be used by default. The family may be specified as the first
70           argument, otherwise tcp will be used.
71
72       status [LINK...]
73           Shows the global and per-link DNS settings currently in effect. If
74           no command is specified, this is the implied default.
75
76       statistics
77           Shows general resolver statistics, including information whether
78           DNSSEC is enabled and available, as well as resolution and
79           validation statistics.
80
81       reset-statistics
82           Resets the statistics counters shown in statistics to zero. This
83           operation requires root privileges.
84
85       flush-caches
86           Flushes all DNS resource record caches the service maintains
87           locally. This is mostly equivalent to sending the SIGUSR2 to the
88           systemd-resolved service.
89
90       reset-server-features
91           Flushes all feature level information the resolver learnt about
92           specific servers, and ensures that the server feature probing logic
93           is started from the beginning with the next look-up request. This
94           is mostly equivalent to sending the SIGRTMIN+1 to the
95           systemd-resolved service.
96
97       dns [LINK [SERVER...]], domain [LINK [DOMAIN...]], default-route [LINK
98       [BOOL...]], llmnr [LINK [MODE]], mdns [LINK [MODE]], dnssec [LINK
99       [MODE]], dnsovertls [LINK [MODE]], nta [LINK [DOMAIN...]]
100           Get/set per-interface DNS configuration. These commands may be used
101           to configure various DNS settings for network interfaces. These
102           commands may be used to inform systemd-resolved or systemd-networkd
103           about per-interface DNS configuration determined through external
104           means. The dns command expects IPv4 or IPv6 address specifications
105           of DNS servers to use. Each address can optionally take a port
106           number separated with ":", a network interface name or index
107           separated with "%", and a Server Name Indication (SNI) separated
108           with "#". When IPv6 address is specified with a port number, then
109           the address must be in the square brackets. That is, the acceptable
110           full formats are "111.222.333.444:9953%ifname#example.com" for IPv4
111           and "[1111:2222::3333]:9953%ifname#example.com" for IPv6. The
112           domain command expects valid DNS domains, possibly prefixed with
113           "~", and configures a per-interface search or route-only domain.
114           The default-route command expects a boolean parameter, and
115           configures whether the link may be used as default route for DNS
116           lookups, i.e. if it is suitable for lookups on domains no other
117           link explicitly is configured for. The llmnr, mdns, dnssec and
118           dnsovertls commands may be used to configure the per-interface
119           LLMNR, MulticastDNS, DNSSEC and DNSOverTLS settings. Finally, nta
120           command may be used to configure additional per-interface DNSSEC
121           NTA domains.
122
123           Commands dns, domain and nta can take a single empty string
124           argument to clear their respective value lists.
125
126           For details about these settings, their possible values and their
127           effect, see the corresponding settings in systemd.network(5).
128
129       revert LINK
130           Revert the per-interface DNS configuration. If the DNS
131           configuration is reverted all per-interface DNS setting are reset
132           to their defaults, undoing all effects of dns, domain,
133           default-route, llmnr, mdns, dnssec, dnsovertls, nta. Note that when
134           a network interface disappears all configuration is lost
135           automatically, an explicit reverting is not necessary in that case.
136
137       monitor
138           Show a continuous stream of local client resolution queries and
139           their responses. Whenever a local query is completed the query's
140           DNS resource lookup key and resource records are shown. Note that
141           this displays queries issued locally only, and does not immediately
142           relate to DNS requests submitted to configured DNS servers or the
143           LLMNR or MulticastDNS zones, as lookups may be answered from the
144           local cache, or might result in multiple DNS transactions (for
145           example to validate DNSSEC information). If CNAME/CNAME redirection
146           chains are followed, a separate query will be displayed for each
147           element of the chain. Use --json= to enable JSON output.
148
149       show-cache
150           Show current cache content, per scope. Use --json= to enable JSON
151           output.
152
153       log-level [LEVEL]
154           If no argument is given, print the current log level of the
155           manager. If an optional argument LEVEL is provided, then the
156           command changes the current log level of the manager to LEVEL
157           (accepts the same values as --log-level= described in systemd(1)).
158

OPTIONS

160       -4, -6
161           By default, when resolving a hostname, both IPv4 and IPv6 addresses
162           are acquired. By specifying -4 only IPv4 addresses are requested,
163           by specifying -6 only IPv6 addresses are requested.
164
165       -i INTERFACE, --interface=INTERFACE
166           Specifies the network interface to execute the query on. This may
167           either be specified as numeric interface index or as network
168           interface string (e.g.  "en0"). Note that this option has no effect
169           if system-wide DNS configuration (as configured in /etc/resolv.conf
170           or /etc/systemd/resolved.conf) in place of per-link configuration
171           is used.
172
173       -p PROTOCOL, --protocol=PROTOCOL
174           Specifies the network protocol for the query. May be one of "dns"
175           (i.e. classic unicast DNS), "llmnr" (Link-Local Multicast Name
176           Resolution[5]), "llmnr-ipv4", "llmnr-ipv6" (LLMNR via the indicated
177           underlying IP protocols), "mdns" (Multicast DNS[6]), "mdns-ipv4",
178           "mdns-ipv6" (MDNS via the indicated underlying IP protocols). By
179           default the lookup is done via all protocols suitable for the
180           lookup. If used, limits the set of protocols that may be used. Use
181           this option multiple times to enable resolving via multiple
182           protocols at the same time. The setting "llmnr" is identical to
183           specifying this switch once with "llmnr-ipv4" and once via
184           "llmnr-ipv6". Note that this option does not force the service to
185           resolve the operation with the specified protocol, as that might
186           require a suitable network interface and configuration. The special
187           value "help" may be used to list known values.
188
189       -t TYPE, --type=TYPE, -c CLASS, --class=CLASS
190           When used in conjunction with the query command, specifies the DNS
191           resource record type (e.g.  A, AAAA, MX, ...) and class (e.g.  IN,
192           ANY, ...) to look up. If these options are used a DNS resource
193           record set matching the specified class and type is requested. The
194           class defaults to IN if only a type is specified. The special value
195           "help" may be used to list known values.
196
197           Without these options resolvectl query provides high-level domain
198           name to address and address to domain name resolution. With these
199           options it provides low-level DNS resource record resolution. The
200           search domain logic is automatically turned off when these options
201           are used, i.e. specified domain names need to be fully qualified
202           domain names. Moreover, IDNA internal domain name translation is
203           turned off as well, i.e. international domain names should be
204           specified in "xn--..."  notation, unless look-up in
205           MulticastDNS/LLMNR is desired, in which case UTF-8 characters
206           should be used.
207
208       --service-address=BOOL
209           Takes a boolean parameter. If true (the default), when doing a
210           service lookup with --service the hostnames contained in the SRV
211           resource records are resolved as well.
212
213       --service-txt=BOOL
214           Takes a boolean parameter. If true (the default), when doing a
215           DNS-SD service lookup with --service the TXT service metadata
216           record is resolved as well.
217
218       --cname=BOOL
219           Takes a boolean parameter. If true (the default), DNS CNAME or
220           DNAME redirections are followed. Otherwise, if a CNAME or DNAME
221           record is encountered while resolving, an error is returned.
222
223       --validate=BOOL
224           Takes a boolean parameter; used in conjunction with query. If true
225           (the default), DNSSEC validation is applied as usual — under the
226           condition that it is enabled for the network and for
227           systemd-resolved.service as a whole. If false, DNSSEC validation is
228           disabled for the specific query, regardless of whether it is
229           enabled for the network or in the service. Note that setting this
230           option to true does not force DNSSEC validation on systems/networks
231           where DNSSEC is turned off. This option is only suitable to turn
232           off such validation where otherwise enabled, not enable validation
233           where otherwise disabled.
234
235       --synthesize=BOOL
236           Takes a boolean parameter; used in conjunction with query. If true
237           (the default), select domains are resolved on the local system,
238           among them "localhost", "_gateway", "_outbound", "_localdnsstub"
239           and "_localdnsproxy" or entries from /etc/hosts. If false these
240           domains are not resolved locally, and either fail (in case of
241           "localhost", "_gateway" or "_outbound" and suchlike) or go to the
242           network via regular DNS/mDNS/LLMNR lookups (in case of /etc/hosts
243           entries).
244
245       --cache=BOOL
246           Takes a boolean parameter; used in conjunction with query. If true
247           (the default), lookups use the local DNS resource record cache. If
248           false, lookups are routed to the network instead, regardless if
249           already available in the local cache.
250
251       --zone=BOOL
252           Takes a boolean parameter; used in conjunction with query. If true
253           (the default), lookups are answered from locally registered LLMNR
254           or mDNS resource records, if defined. If false, locally registered
255           LLMNR/mDNS records are not considered for the lookup request.
256
257       --trust-anchor=BOOL
258           Takes a boolean parameter; used in conjunction with query. If true
259           (the default), lookups for DS and DNSKEY are answered from the
260           local DNSSEC trust anchors if possible. If false, the local trust
261           store is not considered for the lookup request.
262
263       --network=BOOL
264           Takes a boolean parameter; used in conjunction with query. If true
265           (the default), lookups are answered via DNS, LLMNR or mDNS network
266           requests if they cannot be synthesized locally, or be answered from
267           the local cache, zone or trust anchors (see above). If false, the
268           request is not answered from the network and will thus fail if none
269           of the indicated sources can answer them.
270
271       --search=BOOL
272           Takes a boolean parameter. If true (the default), any specified
273           single-label hostnames will be searched in the domains configured
274           in the search domain list, if it is non-empty. Otherwise, the
275           search domain logic is disabled. Note that this option has no
276           effect if --type= is used (see above), in which case the search
277           domain logic is unconditionally turned off.
278
279       --raw[=payload|packet]
280           Dump the answer as binary data. If there is no argument or if the
281           argument is "payload", the payload of the packet is exported. If
282           the argument is "packet", the whole packet is dumped in wire
283           format, prefixed by length specified as a little-endian 64-bit
284           number. This format allows multiple packets to be dumped and
285           unambiguously parsed.
286
287       --legend=BOOL
288           Takes a boolean parameter. If true (the default), column headers
289           and meta information about the query response are shown. Otherwise,
290           this output is suppressed.
291
292       --stale-data=BOOL
293           Takes a boolean parameter; used in conjunction with query. If true
294           (the default), lookups are answered with stale data (expired
295           resource records) if possible. If false, the stale data is not
296           considered for the lookup request.
297
298       --json=MODE
299           Shows output formatted as JSON. Expects one of "short" (for the
300           shortest possible output without any redundant whitespace or line
301           breaks), "pretty" (for a pretty version of the same, with
302           indentation and line breaks) or "off" (to turn off JSON output, the
303           default).
304
305       -j
306           Short for --json=auto
307
308       --no-pager
309           Do not pipe output into a pager.
310
311       -h, --help
312           Print a short help text and exit.
313
314       --version
315           Print a short version string and exit.
316

COMPATIBILITY WITH RESOLVCONF(8)

318       resolvectl is a multi-call binary. When invoked as "resolvconf"
319       (generally achieved by means of a symbolic link of this name to the
320       resolvectl binary) it is run in a limited resolvconf(8) compatibility
321       mode. It accepts mostly the same arguments and pushes all data into
322       systemd-resolved.service(8), similar to how dns and domain commands
323       operate. Note that systemd-resolved.service is the only supported
324       backend, which is different from other implementations of this command.
325
326       /etc/resolv.conf will only be updated with servers added with this
327       command when /etc/resolv.conf is a symlink to
328       /run/systemd/resolve/resolv.conf, and not a static file. See the
329       discussion of /etc/resolv.conf handling in systemd-resolved.service(8).
330
331       Not all operations supported by other implementations are supported
332       natively. Specifically:
333
334       -a
335           Registers per-interface DNS configuration data with
336           systemd-resolved. Expects a network interface name as only command
337           line argument. Reads resolv.conf(5)-compatible DNS configuration
338           data from its standard input. Relevant fields are "nameserver" and
339           "domain"/"search". This command is mostly identical to invoking
340           resolvectl with a combination of dns and domain commands.
341
342       -d
343           Unregisters per-interface DNS configuration data with
344           systemd-resolved. This command is mostly identical to invoking
345           resolvectl revert.
346
347       -f
348           When specified -a and -d will not complain about missing network
349           interfaces and will silently execute no operation in that case.
350
351       -x
352           This switch for "exclusive" operation is supported only partially.
353           It is mapped to an additional configured search domain of "~."  —
354           i.e. ensures that DNS traffic is preferably routed to the DNS
355           servers on this interface, unless there are other, more specific
356           domains configured on other interfaces.
357
358       -m, -p
359           These switches are not supported and are silently ignored.
360
361       -u, -I, -i, -l, -R, -r, -v, -V, --enable-updates, --disable-updates,
362       --are-updates-enabled
363           These switches are not supported and the command will fail if used.
364
365       See resolvconf(8) for details on those command line options.
366

EXAMPLES

368       Example 1. Retrieve the addresses of the "www.0pointer.net" domain (A
369       and AAAA resource records)
370
371           $ resolvectl query www.0pointer.net
372           www.0pointer.net: 2a01:238:43ed:c300:10c3:bcf3:3266:da74
373                             85.214.157.71
374
375           -- Information acquired via protocol DNS in 611.6ms.
376           -- Data is authenticated: no
377
378       Example 2. Retrieve the domain of the "85.214.157.71" IP address (PTR
379       resource record)
380
381           $ resolvectl query 85.214.157.71
382           85.214.157.71: gardel.0pointer.net
383
384           -- Information acquired via protocol DNS in 1.2997s.
385           -- Data is authenticated: no
386
387       Example 3. Retrieve the MX record of the "yahoo.com" domain
388
389           $ resolvectl --legend=no -t MX query yahoo.com
390           yahoo.com. IN MX    1 mta7.am0.yahoodns.net
391           yahoo.com. IN MX    1 mta6.am0.yahoodns.net
392           yahoo.com. IN MX    1 mta5.am0.yahoodns.net
393
394       Example 4. Resolve an SRV service
395
396           $ resolvectl service _xmpp-server._tcp gmail.com
397           _xmpp-server._tcp/gmail.com: alt1.xmpp-server.l.google.com:5269 [priority=20, weight=0]
398                                        173.194.210.125
399                                        alt4.xmpp-server.l.google.com:5269 [priority=20, weight=0]
400                                        173.194.65.125
401                                        ...
402
403       Example 5. Retrieve a PGP key (OPENPGP resource record)
404
405           $ resolvectl openpgp zbyszek@fedoraproject.org
406           d08ee310438ca124a6149ea5cc21b6313b390dce485576eff96f8722._openpgpkey.fedoraproject.org. IN OPENPGPKEY
407                   mQINBFBHPMsBEACeInGYJCb+7TurKfb6wGyTottCDtiSJB310i37/6ZYoeIay/5soJjlMyf
408                   MFQ9T2XNT/0LM6gTa0MpC1st9LnzYTMsT6tzRly1D1UbVI6xw0g0vE5y2Cjk3xUwAynCsSs
409                   ...
410
411       Example 6. Retrieve a TLS key (TLSA resource record)
412
413           $ resolvectl tlsa tcp fedoraproject.org:443
414           _443._tcp.fedoraproject.org IN TLSA 0 0 1 19400be5b7a31fb733917700789d2f0a2471c0c9d506c0e504c06c16d7cb17c0
415                   -- Cert. usage: CA constraint
416                   -- Selector: Full Certificate
417                   -- Matching type: SHA-256
418
419       "tcp" and ":443" are optional and could be skipped.
420

SEE ALSO

422       systemd(1), systemd-resolved.service(8), systemd.dnssd(5), systemd-
423       networkd.service(8), resolvconf(8)
424

NOTES

426        1. DNS-SD
427           https://tools.ietf.org/html/rfc6763
428
429        2. SRV
430           https://tools.ietf.org/html/rfc2782
431
432        3. RFC 7929
433           https://tools.ietf.org/html/rfc7929
434
435        4. RFC 6698
436           https://tools.ietf.org/html/rfc6698
437
438        5. Link-Local Multicast Name Resolution
439           https://tools.ietf.org/html/rfc4795
440
441        6. Multicast DNS
442           https://www.ietf.org/rfc/rfc6762.txt
443
444
445
446systemd 254                                                      RESOLVECTL(1)
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