1RESOLVECTL(1) resolvectl RESOLVECTL(1)
2
6 resolvectl, resolvconf - Resolve domain names, IPV4 and IPv6 addresses,
7 DNS resource records, and services; introspect and reconfigure the DNS
8 resolver
9
11 resolvectl [OPTIONS...] {COMMAND} [NAME...]
12
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 operation the reverse operation is done, and a hostname is
20 retrieved for the specified addresses.
21 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
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 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 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 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 RR is
55 requested. Finally, if only one parameter is specified, it is
56 assumed to be a domain name, that is already prefixed with an SRV
57 type, and an SRV lookup is done (no TXT).
58 openpgp EMAIL@DOMAIN...
60 Query PGP keys stored as OPENPGPKEY[3] resource records. Specified
61 e-mail addresses are converted to the corresponding DNS domain
62 name, and any OPENPGPKEY keys are printed.
63 tlsa [FAMILY] DOMAIN[:PORT]...
65 Query TLS public keys stored as TLSA[4] resource records. A query
66 will be performed for each of the specified names prefixed with the
67 port and family ("_port._family.domain"). The port number may be
68 specified after a colon (":"), otherwise 443 will be used by
69 default. The family may be specified as the first argument,
70 otherwise tcp will be used.
71 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 statistics
77 Shows general resolver statistics, including information whether
78 DNSSEC is enabled and available, as well as resolution and
79 validation statistics.
80 reset-statistics
82 Resets the statistics counters shown in statistics to zero. This
83 operation requires root privileges.
84 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 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 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 Commands dns, domain and nta can take a single empty string
124 argument to clear their respective value lists.
125 For details about these settings, their possible values and their
127 effect, see the corresponding settings in systemd.network(5).
128 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 log-level [LEVEL]
138 If no argument is given, print the current log level of the
139 manager. If an optional argument LEVEL is provided, then the
140 command changes the current log level of the manager to LEVEL
141 (accepts the same values as --log-level= described in systemd(1)).
142
144 -4, -6
145 By default, when resolving a hostname, both IPv4 and IPv6 addresses
146 are acquired. By specifying -4 only IPv4 addresses are requested,
147 by specifying -6 only IPv6 addresses are requested.
148 -i INTERFACE, --interface=INTERFACE
150 Specifies the network interface to execute the query on. This may
151 either be specified as numeric interface index or as network
152 interface string (e.g. "en0"). Note that this option has no effect
153 if system-wide DNS configuration (as configured in /etc/resolv.conf
154 or /etc/systemd/resolved.conf) in place of per-link configuration
155 is used.
156 -p PROTOCOL, --protocol=PROTOCOL
158 Specifies the network protocol for the query. May be one of "dns"
159 (i.e. classic unicast DNS), "llmnr" (Link-Local Multicast Name
160 Resolution[5]), "llmnr-ipv4", "llmnr-ipv6" (LLMNR via the indicated
161 underlying IP protocols), "mdns" (Multicast DNS[6]), "mdns-ipv4",
162 "mdns-ipv6" (MDNS via the indicated underlying IP protocols). By
163 default the lookup is done via all protocols suitable for the
164 lookup. If used, limits the set of protocols that may be used. Use
165 this option multiple times to enable resolving via multiple
166 protocols at the same time. The setting "llmnr" is identical to
167 specifying this switch once with "llmnr-ipv4" and once via
168 "llmnr-ipv6". Note that this option does not force the service to
169 resolve the operation with the specified protocol, as that might
170 require a suitable network interface and configuration. The special
171 value "help" may be used to list known values.
172 -t TYPE, --type=TYPE, -c CLASS, --class=CLASS
174 When used in conjunction with the query command, specifies the DNS
175 resource record type (e.g. A, AAAA, MX, ...) and class (e.g. IN,
176 ANY, ...) to look up. If these options are used a DNS resource
177 record set matching the specified class and type is requested. The
178 class defaults to IN if only a type is specified. The special value
179 "help" may be used to list known values.
180 Without these options resolvectl query provides high-level domain
182 name to address and address to domain name resolution. With these
183 options it provides low-level DNS resource record resolution. The
184 search domain logic is automatically turned off when these options
185 are used, i.e. specified domain names need to be fully qualified
186 domain names. Moreover, IDNA internal domain name translation is
187 turned off as well, i.e. international domain names should be
188 specified in "xn--..." notation, unless look-up in
189 MulticastDNS/LLMNR is desired, in which case UTF-8 characters
190 should be used.
191 --service-address=BOOL
193 Takes a boolean parameter. If true (the default), when doing a
194 service lookup with --service the hostnames contained in the SRV
195 resource records are resolved as well.
196 --service-txt=BOOL
198 Takes a boolean parameter. If true (the default), when doing a
199 DNS-SD service lookup with --service the TXT service metadata
200 record is resolved as well.
201 --cname=BOOL
203 Takes a boolean parameter. If true (the default), DNS CNAME or
204 DNAME redirections are followed. Otherwise, if a CNAME or DNAME
205 record is encountered while resolving, an error is returned.
206 --validate=BOOL
208 Takes a boolean parameter; used in conjunction with query. If true
209 (the default), DNSSEC validation is applied as usual — under the
210 condition that it is enabled for the network and for
211 systemd-resolved.service as a whole. If false, DNSSEC validation is
212 disabled for the specific query, regardless of whether it is
213 enabled for the network or in the service. Note that setting this
214 option to true does not force DNSSEC validation on systems/networks
215 where DNSSEC is turned off. This option is only suitable to turn
216 off such validation where otherwise enabled, not enable validation
217 where otherwise disabled.
218 --synthesize=BOOL
220 Takes a boolean parameter; used in conjunction with query. If true
221 (the default), select domains are resolved on the local system,
222 among them "localhost" and "_gateway" or entries from /etc/hosts.
223 If false these domains are not resolved locally, and either fail
224 (in case of "localhost" or "_gateway" and suchlike) or go to the
225 network via regular DNS/mDNS/LLMNR lookups (in case of /etc/hosts
226 entries).
227 --cache=BOOL
229 Takes a boolean parameter; used in conjunction with query. If true
230 (the default), lookups use the local DNS resource record cache. If
231 false, lookups are routed to the network instead, regardless if
232 already available in the local cache.
233 --zone=BOOL
235 Takes a boolean parameter; used in conjunction with query. If true
236 (the default), lookups are answered from locally registered LLMNR
237 or mDNS resource records, if defined. If false, locally registered
238 LLMNR/mDNS records are not considered for the lookup request.
239 --trust-anchor=BOOL
241 Takes a boolean parameter; used in conjunction with query. If true
242 (the default), lookups for DS and DNSKEY are answered from the
243 local DNSSEC trust anchors if possible. If false, the local trust
244 store is not considered for the lookup request.
245 --network=BOOL
247 Takes a boolean parameter; used in conjunction with query. If true
248 (the default), lookups are answered via DNS, LLMNR or mDNS network
249 requests if they cannot be synthesized locally, or be answered from
250 the local cache, zone or trust anchors (see above). If false, the
251 request is not answered from the network and will thus fail if none
252 of the indicated sources can answer them.
253 --search=BOOL
255 Takes a boolean parameter. If true (the default), any specified
256 single-label hostnames will be searched in the domains configured
257 in the search domain list, if it is non-empty. Otherwise, the
258 search domain logic is disabled. Note that this option has no
259 effect if --type= is used (see above), in which case the search
260 domain logic is unconditionally turned off.
261 --raw[=payload|packet]
263 Dump the answer as binary data. If there is no argument or if the
264 argument is "payload", the payload of the packet is exported. If
265 the argument is "packet", the whole packet is dumped in wire
266 format, prefixed by length specified as a little-endian 64-bit
267 number. This format allows multiple packets to be dumped and
268 unambiguously parsed.
269 --legend=BOOL
271 Takes a boolean parameter. If true (the default), column headers
272 and meta information about the query response are shown. Otherwise,
273 this output is suppressed.
274 -h, --help
276 Print a short help text and exit.
277 --version
279 Print a short version string and exit.
280 --no-pager
282 Do not pipe output into a pager.
283
285 resolvectl is a multi-call binary. When invoked as "resolvconf"
286 (generally achieved by means of a symbolic link of this name to the
287 resolvectl binary) it is run in a limited resolvconf(8) compatibility
288 mode. It accepts mostly the same arguments and pushes all data into
289 systemd-resolved.service(8), similar to how dns and domain commands
290 operate. Note that systemd-resolved.service is the only supported
291 backend, which is different from other implementations of this command.
292 /etc/resolv.conf will only be updated with servers added with this
294 command when /etc/resolv.conf is a symlink to
295 /run/systemd/resolve/resolv.conf, and not a static file. See the
296 discussion of /etc/resolv.conf handling in systemd-resolved.service(8).
297 Not all operations supported by other implementations are supported
299 natively. Specifically:
300 -a
302 Registers per-interface DNS configuration data with
303 systemd-resolved. Expects a network interface name as only command
304 line argument. Reads resolv.conf(5)-compatible DNS configuration
305 data from its standard input. Relevant fields are "nameserver" and
306 "domain"/"search". This command is mostly identical to invoking
307 resolvectl with a combination of dns and domain commands.
308 -d
310 Unregisters per-interface DNS configuration data with
311 systemd-resolved. This command is mostly identical to invoking
312 resolvectl revert.
313 -f
315 When specified -a and -d will not complain about missing network
316 interfaces and will silently execute no operation in that case.
317 -x
319 This switch for "exclusive" operation is supported only partially.
320 It is mapped to an additional configured search domain of "~." —
321 i.e. ensures that DNS traffic is preferably routed to the DNS
322 servers on this interface, unless there are other, more specific
323 domains configured on other interfaces.
324 -m, -p
326 These switches are not supported and are silently ignored.
327 -u, -I, -i, -l, -R, -r, -v, -V, --enable-updates, --disable-updates,
329 --are-updates-enabled
330 These switches are not supported and the command will fail if used.
331 See resolvconf(8) for details on those command line options.
333
335 Example 1. Retrieve the addresses of the "www.0pointer.net" domain
336 $ resolvectl query www.0pointer.net
338 www.0pointer.net: 2a01:238:43ed:c300:10c3:bcf3:3266:da74
339 85.214.157.71
340 -- Information acquired via protocol DNS in 611.6ms.
342 -- Data is authenticated: no
343 Example 2. Retrieve the domain of the "85.214.157.71" IP address
345 $ resolvectl query 85.214.157.71
347 85.214.157.71: gardel.0pointer.net
348 -- Information acquired via protocol DNS in 1.2997s.
350 -- Data is authenticated: no
351 Example 3. Retrieve the MX record of the "yahoo.com" domain
353 $ resolvectl --legend=no -t MX query yahoo.com
355 yahoo.com. IN MX 1 mta7.am0.yahoodns.net
356 yahoo.com. IN MX 1 mta6.am0.yahoodns.net
357 yahoo.com. IN MX 1 mta5.am0.yahoodns.net
358 Example 4. Resolve an SRV service
360 $ resolvectl service _xmpp-server._tcp gmail.com
362 _xmpp-server._tcp/gmail.com: alt1.xmpp-server.l.google.com:5269 [priority=20, weight=0]
363 173.194.210.125
364 alt4.xmpp-server.l.google.com:5269 [priority=20, weight=0]
365 173.194.65.125
366 ...
367 Example 5. Retrieve a PGP key
369 $ resolvectl openpgp zbyszek@fedoraproject.org
371 d08ee310438ca124a6149ea5cc21b6313b390dce485576eff96f8722._openpgpkey.fedoraproject.org. IN OPENPGPKEY
372 mQINBFBHPMsBEACeInGYJCb+7TurKfb6wGyTottCDtiSJB310i37/6ZYoeIay/5soJjlMyf
373 MFQ9T2XNT/0LM6gTa0MpC1st9LnzYTMsT6tzRly1D1UbVI6xw0g0vE5y2Cjk3xUwAynCsSs
374 ...
375 Example 6. Retrieve a TLS key ("tcp" and ":443" could be skipped)
377 $ resolvectl tlsa tcp fedoraproject.org:443
379 _443._tcp.fedoraproject.org IN TLSA 0 0 1 19400be5b7a31fb733917700789d2f0a2471c0c9d506c0e504c06c16d7cb17c0
380 -- Cert. usage: CA constraint
381 -- Selector: Full Certificate
382 -- Matching type: SHA-256
383
385 systemd(1), systemd-resolved.service(8), systemd.dnssd(5), systemd-
386 networkd.service(8), resolvconf(8)
387
389 1. DNS-SD
390 https://tools.ietf.org/html/rfc6763
391 2. SRV
393 https://tools.ietf.org/html/rfc2782
394 3. OPENPGPKEY
396 https://tools.ietf.org/html/rfc7929
397 4. TLSA
399 https://tools.ietf.org/html/rfc6698
400 5. Link-Local Multicast Name Resolution
402 https://tools.ietf.org/html/rfc4795
403 6. Multicast DNS
405 https://www.ietf.org/rfc/rfc6762.txt
406systemd 248 RESOLVECTL(1)