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" host name or all data from
29 /etc/hosts.
30
32 -4, -6
33 By default, when resolving a hostname, both IPv4 and IPv6 addresses
34 are acquired. By specifying -4 only IPv4 addresses are requested,
35 by specifying -6 only IPv6 addresses are requested.
36 -i INTERFACE, --interface=INTERFACE
38 Specifies the network interface to execute the query on. This may
39 either be specified as numeric interface index or as network
40 interface string (e.g. "en0"). Note that this option has no effect
41 if system-wide DNS configuration (as configured in /etc/resolv.conf
42 or /etc/systemd/resolve.conf) in place of per-link configuration is
43 used.
44 -p PROTOCOL, --protocol=PROTOCOL
46 Specifies the network protocol for the query. May be one of "dns"
47 (i.e. classic unicast DNS), "llmnr" (Link-Local Multicast Name
48 Resolution[1]), "llmnr-ipv4", "llmnr-ipv6" (LLMNR via the indicated
49 underlying IP protocols), "mdns" (Multicast DNS[2]), "mdns-ipv4",
50 "mdns-ipv6" (MDNS via the indicated underlying IP protocols). By
51 default the lookup is done via all protocols suitable for the
52 lookup. If used, limits the set of protocols that may be used. Use
53 this option multiple times to enable resolving via multiple
54 protocols at the same time. The setting "llmnr" is identical to
55 specifying this switch once with "llmnr-ipv4" and once via
56 "llmnr-ipv6". Note that this option does not force the service to
57 resolve the operation with the specified protocol, as that might
58 require a suitable network interface and configuration. The special
59 value "help" may be used to list known values.
60 -t TYPE, --type=TYPE, -c CLASS, --class=CLASS
62 Specifies the DNS resource record type (e.g. A, AAAA, MX, ...) and
63 class (e.g. IN, ANY, ...) to look up. If these options are used a
64 DNS resource record set matching the specified class and type is
65 requested. The class defaults to IN if only a type is specified.
66 The special value "help" may be used to list known values.
67 --service-address=BOOL
69 Takes a boolean parameter. If true (the default), when doing a
70 service lookup with --service the hostnames contained in the SRV
71 resource records are resolved as well.
72 --service-txt=BOOL
74 Takes a boolean parameter. If true (the default), when doing a
75 DNS-SD service lookup with --service the TXT service metadata
76 record is resolved as well.
77 --cname=BOOL
79 Takes a boolean parameter. If true (the default), DNS CNAME or
80 DNAME redirections are followed. Otherwise, if a CNAME or DNAME
81 record is encountered while resolving, an error is returned.
82 --search=BOOL
84 Takes a boolean parameter. If true (the default), any specified
85 single-label hostnames will be searched in the domains configured
86 in the search domain list, if it is non-empty. Otherwise, the
87 search domain logic is disabled.
88 --raw[=payload|packet]
90 Dump the answer as binary data. If there is no argument or if the
91 argument is "payload", the payload of the packet is exported. If
92 the argument is "packet", the whole packet is dumped in wire
93 format, prefixed by length specified as a little-endian 64-bit
94 number. This format allows multiple packets to be dumped and
95 unambiguously parsed.
96 --legend=BOOL
98 Takes a boolean parameter. If true (the default), column headers
99 and meta information about the query response are shown. Otherwise,
100 this output is suppressed.
101 -h, --help
103 Print a short help text and exit.
104 --version
106 Print a short version string and exit.
107 --no-pager
109 Do not pipe output into a pager.
110
112 query HOSTNAME|ADDRESS...
113 Resolve domain names, IPv4 and IPv6 addresses.
114 service [[NAME] TYPE] DOMAIN
116 Resolve DNS-SD[3] and SRV[4] services, depending on the specified
117 list of parameters. If three parameters are passed the first is
118 assumed to be the DNS-SD service name, the second the SRV service
119 type, and the third the domain to search in. In this case a full
120 DNS-SD style SRV and TXT lookup is executed. If only two parameters
121 are specified, the first is assumed to be the SRV service type, and
122 the second the domain to look in. In this case no TXT RR is
123 requested. Finally, if only one parameter is specified, it is
124 assumed to be a domain name, that is already prefixed with an SRV
125 type, and an SRV lookup is done (no TXT).
126 openpgp EMAIL@DOMAIN...
128 Query PGP keys stored as OPENPGPKEY[5] resource records. Specified
129 e-mail addresses are converted to the corresponding DNS domain
130 name, and any OPENPGPKEY keys are printed.
131 tlsa [FAMILY] DOMAIN[:PORT]...
133 Query TLS public keys stored as TLSA[6] resource records. A query
134 will be performed for each of the specified names prefixed with the
135 port and family ("_port._family.domain"). The port number may be
136 specified after a colon (":"), otherwise 443 will be used by
137 default. The family may be specified as the first argument,
138 otherwise tcp will be used.
139 status [LINK...]
141 Shows the global and per-link DNS settings currently in effect. If
142 no command is specified, this is the implied default.
143 statistics
145 Shows general resolver statistics, including information whether
146 DNSSEC is enabled and available, as well as resolution and
147 validation statistics.
148 reset-statistics
150 Resets the statistics counters shown in statistics to zero. This
151 operation requires root privileges.
152 flush-caches
154 Flushes all DNS resource record caches the service maintains
155 locally. This is mostly equivalent to sending the SIGUSR2 to the
156 systemd-resolved service.
157 reset-server-features
159 Flushes all feature level information the resolver learnt about
160 specific servers, and ensures that the server feature probing logic
161 is started from the beginning with the next look-up request. This
162 is mostly equivalent to sending the SIGRTMIN+1 to the
163 systemd-resolved service.
164 dns [LINK [SERVER...]], domain [LINK [DOMAIN...]], default-route [LINK
166 [BOOL...]], llmnr [LINK [MODE]], mdns [LINK [MODE]], dnssec [LINK
167 [MODE]], dnsovertls [LINK [MODE]], nta [LINK [DOMAIN...]]
168 Get/set per-interface DNS configuration. These commands may be used
169 to configure various DNS settings for network interfaces. These
170 commands may be used to inform systemd-resolved or systemd-networkd
171 about per-interface DNS configuration determined through external
172 means. The dns command expects IPv4 or IPv6 address specifications
173 of DNS servers to use. The domain command expects valid DNS
174 domains, possibly prefixed with "~", and configures a per-interface
175 search or route-only domain. The default-route command expects a
176 boolean parameter, and configures whether the link may be used as
177 default route for DNS lookups, i.e. if it is suitable for lookups
178 on domains no other link explicitly is configured for. The llmnr,
179 mdns, dnssec and dnsovertls commands may be used to configure the
180 per-interface LLMNR, MulticastDNS, DNSSEC and DNSOverTLS settings.
181 Finally, nta command may be used to configure additional
182 per-interface DNSSEC NTA domains.
183 Options dns, domain and nta can take a single empty string argument
185 to clear their respective value lists.
186 For details about these settings, their possible values and their
188 effect, see the corresponding options in systemd.network(5).
189 revert LINK
191 Revert the per-interface DNS configuration. If the DNS
192 configuration is reverted all per-interface DNS setting are reset
193 to their defaults, undoing all effects of dns, domain,
194 default-route, llmnr, mdns, dnssec, dnsovertls, nta. Note that when
195 a network interface disappears all configuration is lost
196 automatically, an explicit reverting is not necessary in that case.
197
199 resolvectl is a multi-call binary. When invoked as "resolvconf"
200 (generally achieved by means of a symbolic link of this name to the
201 resolvectl binary) it is run in a limited resolvconf(8) compatibility
202 mode. It accepts mostly the same arguments and pushes all data into
203 systemd-resolved.service(8), similar to how dns and domain commands
204 operate. Note that systemd-resolved.service is the only supported
205 backend, which is different from other implementations of this command.
206 Note that not all operations supported by other implementations are
207 supported natively. Specifically:
208 -a
210 Registers per-interface DNS configuration data with
211 systemd-resolved. Expects a network interface name as only command
212 line argument. Reads resolv.conf(5) compatible DNS configuration
213 data from its standard input. Relevant fields are "nameserver" and
214 "domain"/"search". This command is mostly identical to invoking
215 resolvectl with a combination of dns and domain commands.
216 -d
218 Unregisters per-interface DNS configuration data with
219 systemd-resolved. This command is mostly identical to invoking
220 resolvectl revert.
221 -f
223 When specified -a and -d will not complain about missing network
224 interfaces and will silently execute no operation in that case.
225 -x
227 This switch for "exclusive" operation is supported only partially.
228 It is mapped to an additional configured search domain of "~." —
229 i.e. ensures that DNS traffic is preferably routed to the DNS
230 servers on this interface, unless there are other, more specific
231 domains configured on other interfaces.
232 -m, -p
234 These switches are not supported and are silently ignored.
235 -u, -I, -i, -l, -R, -r, -v, -V, --enable-updates, --disable-updates,
237 --are-updates-enabled
238 These switches are not supported and the command will fail if used.
239 See resolvconf(8) for details on this command line options.
241
243 Example 1. Retrieve the addresses of the "www.0pointer.net" domain
244 $ resolvectl query www.0pointer.net
246 www.0pointer.net: 2a01:238:43ed:c300:10c3:bcf3:3266:da74
247 85.214.157.71
248 -- Information acquired via protocol DNS in 611.6ms.
250 -- Data is authenticated: no
251 Example 2. Retrieve the domain of the "85.214.157.71" IP address
253 $ resolvectl query 85.214.157.71
255 85.214.157.71: gardel.0pointer.net
256 -- Information acquired via protocol DNS in 1.2997s.
258 -- Data is authenticated: no
259 Example 3. Retrieve the MX record of the "yahoo.com" domain
261 $ resolvectl --legend=no -t MX query yahoo.com
263 yahoo.com. IN MX 1 mta7.am0.yahoodns.net
264 yahoo.com. IN MX 1 mta6.am0.yahoodns.net
265 yahoo.com. IN MX 1 mta5.am0.yahoodns.net
266 Example 4. Resolve an SRV service
268 $ resolvectl service _xmpp-server._tcp gmail.com
270 _xmpp-server._tcp/gmail.com: alt1.xmpp-server.l.google.com:5269 [priority=20, weight=0]
271 173.194.210.125
272 alt4.xmpp-server.l.google.com:5269 [priority=20, weight=0]
273 173.194.65.125
274 ...
275 Example 5. Retrieve a PGP key
277 $ resolvectl openpgp zbyszek@fedoraproject.org
279 d08ee310438ca124a6149ea5cc21b6313b390dce485576eff96f8722._openpgpkey.fedoraproject.org. IN OPENPGPKEY
280 mQINBFBHPMsBEACeInGYJCb+7TurKfb6wGyTottCDtiSJB310i37/6ZYoeIay/5soJjlMyf
281 MFQ9T2XNT/0LM6gTa0MpC1st9LnzYTMsT6tzRly1D1UbVI6xw0g0vE5y2Cjk3xUwAynCsSs
282 ...
283 Example 6. Retrieve a TLS key ("tcp" and ":443" could be skipped)
285 $ resolvectl tlsa tcp fedoraproject.org:443
287 _443._tcp.fedoraproject.org IN TLSA 0 0 1 19400be5b7a31fb733917700789d2f0a2471c0c9d506c0e504c06c16d7cb17c0
288 -- Cert. usage: CA constraint
289 -- Selector: Full Certificate
290 -- Matching type: SHA-256
291
293 systemd(1), systemd-resolved.service(8), systemd.dnssd(5), systemd-
294 networkd.service(8), resolvconf(8)
295
297 1. Link-Local Multicast Name Resolution
298 https://tools.ietf.org/html/rfc4795
299 2. Multicast DNS
301 https://www.ietf.org/rfc/rfc6762.txt
302 3. DNS-SD
304 https://tools.ietf.org/html/rfc6763
305 4. SRV
307 https://tools.ietf.org/html/rfc2782
308 5. OPENPGPKEY
310 https://tools.ietf.org/html/rfc7929
311 6. TLSA
313 https://tools.ietf.org/html/rfc6698
314systemd 243 RESOLVECTL(1)