man/resolvectl.xml

   1 <?xml version='1.0'?>
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   3   "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
   4 <!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
   5
   6 <refentry id="resolvectl" conditional='ENABLE_RESOLVE'
   7           xmlns:xi="http://www.w3.org/2001/XInclude">
   8
   9   <refentryinfo>
  10     <title>resolvectl</title>
  11     <productname>systemd</productname>
  12   </refentryinfo>
  13
  14   <refmeta>
  15     <refentrytitle>resolvectl</refentrytitle>
  16     <manvolnum>1</manvolnum>
  17   </refmeta>
  18
  19   <refnamediv>
  20     <refname>resolvectl</refname>
  21     <refname>resolvconf</refname>
  22     <refpurpose>Resolve domain names, IPV4 and IPv6 addresses, DNS resource records, and services; introspect and reconfigure the DNS resolver</refpurpose>
  23   </refnamediv>
  24
  25   <refsynopsisdiv>
  26     <cmdsynopsis>
  27       <command>resolvectl</command>
  28       <arg choice="opt" rep="repeat">OPTIONS</arg>
  29       <arg choice="req">COMMAND</arg>
  30       <arg choice="opt" rep="repeat">NAME</arg>
  31     </cmdsynopsis>
  32   </refsynopsisdiv>
  33
  34   <refsect1>
  35     <title>Description</title>
  36
  37     <para><command>resolvectl</command> may be used to resolve domain names, IPv4 and IPv6 addresses, DNS resource
  38     records and services with the
  39     <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
  40     resolver service. By default, the specified list of parameters will be resolved as hostnames, retrieving their IPv4
  41     and IPv6 addresses. If the parameters specified are formatted as IPv4 or IPv6 addresses the reverse operation is
  42     done, and a hostname is retrieved for the specified addresses.</para>
  43
  44     <para>The program's output contains information about the protocol used for the look-up and on which network
  45     interface the data was discovered. It also contains information on whether the information could be
  46     authenticated. All data for which local DNSSEC validation succeeds is considered authenticated. Moreover all data
  47     originating from local, trusted sources is also reported authenticated, including resolution of the local host
  48     name, the <literal>localhost</literal> hostname or all data from <filename>/etc/hosts</filename>.</para>
  49   </refsect1>
  50
  51   <refsect1>
  52     <title>Commands</title>
  53     <variablelist>
  54
  55       <varlistentry>
  56         <term><command>query</command> <replaceable>HOSTNAME|ADDRESS</replaceable>…</term>
  57
  58         <listitem><para>Resolve domain names, as well as IPv4 and IPv6 addresses. When used in conjunction
  59         with <option>--type=</option> or <option>--class=</option> (see below), resolves low-level DNS
  60         resource records.</para>
  61
  62         <para>If a single-label domain name is specified it is searched for according to the configured
  63         search domains — unless <option>--search=no</option> or
  64         <option>--type=</option>/<option>--class=</option> are specified, both of which turn this logic
  65         off.</para>
  66
  67         <para>If an international domain name is specified, it is automatically translated according to IDNA
  68         rules when resolved via classic DNS — but not for look-ups via MulticastDNS or LLMNR. If
  69         <option>--type=</option>/<option>--class=</option> is used IDNA translation is turned off and domain
  70         names are processed as specified.</para>
  71
  72         <para>If combined with <option>--json=</option> (only supported in combination with
  73         <option>--type=</option>) will output the resource record data in a JSON object.</para>
  74
  75         <xi:include href="version-info.xml" xpointer="v239"/></listitem>
  76       </varlistentry>
  77
  78       <varlistentry>
  79         <term><command>service</command>
  80         [[<replaceable>NAME</replaceable>] <replaceable>TYPE</replaceable>]
  81         <replaceable>DOMAIN</replaceable></term>
  82
  83         <listitem><para>Resolve <ulink url="https://tools.ietf.org/html/rfc6763">RFC 6763 DNS-SD</ulink> and
  84         <ulink url="https://tools.ietf.org/html/rfc2782">RFC 2782 SRV</ulink> services, depending on the
  85         specified list of parameters. If three parameters are passed the first is assumed to be the DNS-SD
  86         service name, the second the <constant class='dns'>SRV</constant> service type, and the third the
  87         domain to search in. In this case a full DNS-SD style <constant class='dns'>SRV</constant> and
  88         <constant class='dns'>TXT</constant> lookup is executed. If only two parameters are specified, the
  89         first is assumed to be the <constant class='dns'>SRV</constant> service type, and the second the
  90         domain to look in. In this case no <constant class='dns'>TXT</constant> resource record is requested.
  91         Finally, if only one parameter is specified, it is assumed to be a domain name, that is already
  92         prefixed with an <constant class='dns'>SRV</constant> type, and an <constant
  93         class='dns'>SRV</constant> lookup is done (no <constant class='dns'>TXT</constant>).</para>
  94
  95         <xi:include href="version-info.xml" xpointer="v239"/></listitem>
  96       </varlistentry>
  97
  98       <varlistentry>
  99         <term><command>openpgp</command> <replaceable>EMAIL@DOMAIN</replaceable>…</term>
 100
 101         <listitem><para>Query PGP keys stored as <constant class='dns'>OPENPGPKEY</constant> resource records,
 102         see <ulink url="https://tools.ietf.org/html/rfc7929">RFC 7929</ulink>. Specified e-mail addresses
 103         are converted to the corresponding DNS domain name, and any <constant class='dns'>OPENPGPKEY</constant>
 104         keys are printed.</para>
 105
 106         <xi:include href="version-info.xml" xpointer="v239"/></listitem>
 107       </varlistentry>
 108
 109       <varlistentry>
 110         <term><command>tlsa</command>
 111         [<replaceable>FAMILY</replaceable>]
 112         <replaceable>DOMAIN</replaceable>[:<replaceable>PORT</replaceable>]…</term>
 113
 114         <listitem><para>Query TLS public keys stored as <constant class='dns'>TLSA</constant> resource
 115         records, see <ulink url="https://tools.ietf.org/html/rfc6698">RFC 6698</ulink>. A query will be
 116         performed for each of the specified names prefixed with the port and family
 117         (<literal>_<replaceable>port</replaceable>._<replaceable>family</replaceable>.<replaceable>domain</replaceable></literal>).
 118         The port number may be specified after a colon (<literal>:</literal>), otherwise
 119         <constant>443</constant> will be used by default. The family may be specified as the first argument,
 120         otherwise <constant>tcp</constant> will be used.</para>
 121
 122         <xi:include href="version-info.xml" xpointer="v239"/></listitem>
 123       </varlistentry>
 124
 125       <varlistentry>
 126         <term><command>status</command> [<replaceable>LINK</replaceable>…]</term>
 127
 128         <listitem><para>Shows the global and per-link DNS settings currently in effect. If no command is specified,
 129         this is the implied default.</para>
 130
 131         <xi:include href="version-info.xml" xpointer="v239"/></listitem>
 132       </varlistentry>
 133
 134       <varlistentry>
 135         <term><command>statistics</command></term>
 136
 137         <listitem><para>Shows general resolver statistics, including information whether DNSSEC is
 138         enabled and available, as well as resolution and validation statistics.</para>
 139
 140         <xi:include href="version-info.xml" xpointer="v239"/></listitem>
 141       </varlistentry>
 142
 143       <varlistentry>
 144         <term><command>reset-statistics</command></term>
 145
 146         <listitem><para>Resets the statistics counters shown in <command>statistics</command> to zero.
 147         This operation requires root privileges.</para>
 148
 149         <xi:include href="version-info.xml" xpointer="v239"/></listitem>
 150       </varlistentry>
 151
 152       <varlistentry>
 153         <term><command>flush-caches</command></term>
 154
 155         <listitem><para>Flushes all DNS resource record caches the service maintains locally. This is mostly
 156         equivalent to sending the <constant>SIGUSR2</constant> to the <command>systemd-resolved</command>
 157         service.</para>
 158
 159         <xi:include href="version-info.xml" xpointer="v239"/></listitem>
 160       </varlistentry>
 161
 162       <varlistentry>
 163         <term><command>reset-server-features</command></term>
 164
 165         <listitem><para>Flushes all feature level information the resolver learnt about specific servers, and ensures
 166         that the server feature probing logic is started from the beginning with the next look-up request. This is
 167         mostly equivalent to sending the <constant>SIGRTMIN+1</constant> to the <command>systemd-resolved</command>
 168         service.</para>
 169
 170         <xi:include href="version-info.xml" xpointer="v239"/></listitem>
 171       </varlistentry>
 172
 173       <varlistentry>
 174         <term><command>dns</command> [<replaceable>LINK</replaceable> [<replaceable>SERVER</replaceable>…]]</term>
 175         <term><command>domain</command> [<replaceable>LINK</replaceable> [<replaceable>DOMAIN</replaceable>…]]</term>
 176         <term><command>default-route</command> [<replaceable>LINK</replaceable> [<replaceable>BOOL</replaceable>…]]</term>
 177         <term><command>llmnr</command> [<replaceable>LINK</replaceable> [<replaceable>MODE</replaceable>]]</term>
 178         <term><command>mdns</command> [<replaceable>LINK</replaceable> [<replaceable>MODE</replaceable>]]</term>
 179         <term><command>dnssec</command> [<replaceable>LINK</replaceable> [<replaceable>MODE</replaceable>]]</term>
 180         <term><command>dnsovertls</command> [<replaceable>LINK</replaceable> [<replaceable>MODE</replaceable>]]</term>
 181         <term><command>nta</command> [<replaceable>LINK</replaceable> [<replaceable>DOMAIN</replaceable>…]]</term>
 182
 183         <listitem>
 184           <para>Get/set per-interface DNS configuration. These commands may be used to configure various DNS
 185           settings for network interfaces. These commands may be used to inform
 186           <command>systemd-resolved</command> or <command>systemd-networkd</command> about per-interface DNS
 187           configuration determined through external means. The <command>dns</command> command expects IPv4 or
 188           IPv6 address specifications of DNS servers to use. Each address can optionally take a port number
 189           separated with <literal>:</literal>, a network interface name or index separated with
 190           <literal>%</literal>, and a Server Name Indication (SNI) separated with <literal>#</literal>. When
 191           IPv6 address is specified with a port number, then the address must be in the square brackets. That
 192           is, the acceptable full formats are <literal>111.222.333.444:9953%ifname#example.com</literal> for
 193           IPv4 and <literal>[1111:2222::3333]:9953%ifname#example.com</literal> for IPv6. The
 194           <command>domain</command> command expects valid DNS domains, possibly prefixed with
 195           <literal>~</literal>, and configures a per-interface search or route-only domain. The
 196           <command>default-route</command> command expects a boolean parameter, and configures whether the
 197           link may be used as default route for DNS lookups, i.e. if it is suitable for lookups on domains no
 198           other link explicitly is configured for. The <command>llmnr</command>, <command>mdns</command>,
 199           <command>dnssec</command> and <command>dnsovertls</command> commands may be used to configure the
 200           per-interface LLMNR, MulticastDNS, DNSSEC and DNSOverTLS settings. Finally, <command>nta</command>
 201           command may be used to configure additional per-interface DNSSEC NTA domains.</para>
 202
 203           <para>Commands <command>dns</command>, <command>domain</command> and <command>nta</command> can take
 204           a single empty string argument to clear their respective value lists.</para>
 205
 206           <para>For details about these settings, their possible values and their effect, see the
 207           corresponding settings in
 208           <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
 209
 210           <xi:include href="version-info.xml" xpointer="v239"/>
 211         </listitem>
 212       </varlistentry>
 213
 214       <varlistentry>
 215         <term><command>revert <replaceable>LINK</replaceable></command></term>
 216
 217         <listitem><para>Revert the per-interface DNS configuration. If the DNS configuration is reverted all
 218         per-interface DNS setting are reset to their defaults, undoing all effects of <command>dns</command>,
 219         <command>domain</command>, <command>default-route</command>, <command>llmnr</command>,
 220         <command>mdns</command>, <command>dnssec</command>, <command>dnsovertls</command>,
 221         <command>nta</command>. Note that when a network interface disappears all configuration is lost
 222         automatically, an explicit reverting is not necessary in that case.</para>
 223
 224         <xi:include href="version-info.xml" xpointer="v239"/></listitem>
 225       </varlistentry>
 226
 227       <varlistentry>
 228         <term><command>monitor</command></term>
 229
 230         <listitem><para>Show a continuous stream of local client resolution queries and their
 231         responses. Whenever a local query is completed the query's DNS resource lookup key and resource
 232         records are shown. Note that this displays queries issued locally only, and does not immediately
 233         relate to DNS requests submitted to configured DNS servers or the LLMNR or MulticastDNS zones, as
 234         lookups may be answered from the local cache, or might result in multiple DNS transactions (for
 235         example to validate DNSSEC information). If CNAME/CNAME redirection chains are followed, a separate
 236         query will be displayed for each element of the chain. Use <option>--json=</option> to enable JSON
 237         output.</para>
 238
 239         <xi:include href="version-info.xml" xpointer="v252"/></listitem>
 240       </varlistentry>
 241
 242       <varlistentry>
 243         <term><command>show-cache</command></term>
 244
 245         <listitem><para>Show current cache content, per scope. Use <option>--json=</option> to enable JSON
 246         output.</para>
 247
 248         <xi:include href="version-info.xml" xpointer="v254"/></listitem>
 249       </varlistentry>
 250
 251       <varlistentry>
 252         <term><command>show-server-state</command></term>
 253
 254         <listitem><para>Show detailed server state information, per DNS Server. Use <option>--json=</option>
 255         to enable JSON output.</para>
 256
 257         <xi:include href="version-info.xml" xpointer="v255"/></listitem>
 258       </varlistentry>
 259
 260       <xi:include href="systemctl.xml" xpointer="log-level" />
 261     </variablelist>
 262   </refsect1>
 263
 264   <refsect1>
 265     <title>Options</title>
 266     <variablelist>
 267       <varlistentry>
 268         <term><option>-4</option></term>
 269         <term><option>-6</option></term>
 270
 271         <listitem><para>By default, when resolving a hostname, both IPv4 and IPv6
 272         addresses are acquired. By specifying <option>-4</option> only IPv4 addresses are requested, by specifying
 273         <option>-6</option> only IPv6 addresses are requested.</para>
 274
 275         <xi:include href="version-info.xml" xpointer="v239"/>
 276         </listitem>
 277       </varlistentry>
 278
 279       <varlistentry>
 280         <term><option>-i</option> <replaceable>INTERFACE</replaceable></term>
 281         <term><option>--interface=<replaceable>INTERFACE</replaceable></option></term>
 282
 283         <listitem><para>Specifies the network interface to execute the query on. This may either be specified as numeric
 284         interface index or as network interface string (e.g. <literal>en0</literal>). Note that this option has no
 285         effect if system-wide DNS configuration (as configured in <filename>/etc/resolv.conf</filename> or
 286         <filename>/etc/systemd/resolved.conf</filename>) in place of per-link configuration is used.</para>
 287
 288         <xi:include href="version-info.xml" xpointer="v239"/></listitem>
 289       </varlistentry>
 290
 291       <varlistentry>
 292         <term><option>-p</option> <replaceable>PROTOCOL</replaceable></term>
 293         <term><option>--protocol=<replaceable>PROTOCOL</replaceable></option></term>
 294
 295         <listitem><para>Specifies the network protocol for the query. May be one of <literal>dns</literal>
 296         (i.e. classic unicast DNS), <literal>llmnr</literal> (<ulink
 297         url="https://tools.ietf.org/html/rfc4795">Link-Local Multicast Name Resolution</ulink>),
 298         <literal>llmnr-ipv4</literal>, <literal>llmnr-ipv6</literal> (LLMNR via the indicated underlying IP
 299         protocols), <literal>mdns</literal> (<ulink url="https://www.ietf.org/rfc/rfc6762.txt">Multicast DNS</ulink>),
 300         <literal>mdns-ipv4</literal>, <literal>mdns-ipv6</literal> (MDNS via the indicated underlying IP protocols).
 301         By default the lookup is done via all protocols suitable for the lookup. If used, limits the set of
 302         protocols that may be used. Use this option multiple times to enable resolving via multiple protocols at the
 303         same time. The setting <literal>llmnr</literal> is identical to specifying this switch once with
 304         <literal>llmnr-ipv4</literal> and once via <literal>llmnr-ipv6</literal>. Note that this option does not force
 305         the service to resolve the operation with the specified protocol, as that might require a suitable network
 306         interface and configuration.
 307         The special value <literal>help</literal> may be used to list known values.
 308         </para>
 309
 310         <xi:include href="version-info.xml" xpointer="v239"/></listitem>
 311       </varlistentry>
 312
 313       <varlistentry>
 314         <term><option>-t</option> <replaceable>TYPE</replaceable></term>
 315         <term><option>--type=<replaceable>TYPE</replaceable></option></term>
 316         <term><option>-c</option> <replaceable>CLASS</replaceable></term>
 317         <term><option>--class=<replaceable>CLASS</replaceable></option></term>
 318
 319         <listitem><para>When used in conjunction with the <command>query</command> command, specifies the DNS
 320         resource record type (e.g. <constant class='dns'>A</constant>, <constant class='dns'>AAAA</constant>,
 321         <constant class='dns'>MX</constant>, …) and class (e.g. <constant>IN</constant>,
 322         <constant>ANY</constant>, …) to look up. If these options are used a DNS resource record set matching
 323         the specified class and type is requested. The class defaults to <constant>IN</constant> if only a
 324         type is specified. The special value <literal>help</literal> may be used to list known values.</para>
 325
 326         <para>Without these options <command>resolvectl query</command> provides high-level domain name to
 327         address and address to domain name resolution. With these options it provides low-level DNS resource
 328         record resolution. The search domain logic is automatically turned off when these options are used,
 329         i.e. specified domain names need to be fully qualified domain names. Moreover, IDNA internal domain
 330         name translation is turned off as well, i.e. international domain names should be specified in
 331         <literal>xn--…</literal> notation, unless look-up in MulticastDNS/LLMNR is desired, in which case
 332         UTF-8 characters should be used.</para>
 333
 334         <xi:include href="version-info.xml" xpointer="v239"/></listitem>
 335       </varlistentry>
 336
 337       <varlistentry>
 338         <term><option>--service-address=<replaceable>BOOL</replaceable></option></term>
 339
 340         <listitem><para>Takes a boolean parameter. If true (the default), when doing a service lookup with
 341         <option>--service</option> the hostnames contained in the <constant class='dns'>SRV</constant>
 342         resource records are resolved as well.</para>
 343
 344         <xi:include href="version-info.xml" xpointer="v239"/></listitem>
 345       </varlistentry>
 346
 347       <varlistentry>
 348         <term><option>--service-txt=<replaceable>BOOL</replaceable></option></term>
 349
 350         <listitem><para>Takes a boolean parameter. If true (the default), when doing a DNS-SD service lookup
 351         with <option>--service</option> the <constant class='dns'>TXT</constant> service metadata record is
 352         resolved as well.</para>
 353
 354         <xi:include href="version-info.xml" xpointer="v239"/></listitem>
 355       </varlistentry>
 356
 357       <varlistentry>
 358         <term><option>--cname=<replaceable>BOOL</replaceable></option></term>
 359
 360         <listitem><para>Takes a boolean parameter. If true (the default), DNS <constant
 361         class='dns'>CNAME</constant> or <constant class='dns'>DNAME</constant> redirections are
 362         followed. Otherwise, if a CNAME or DNAME record is encountered while resolving, an error is
 363         returned.</para>
 364
 365         <xi:include href="version-info.xml" xpointer="v239"/></listitem>
 366       </varlistentry>
 367
 368       <varlistentry>
 369         <term><option>--validate=<replaceable>BOOL</replaceable></option></term>
 370
 371         <listitem><para>Takes a boolean parameter; used in conjunction with <command>query</command>. If true
 372         (the default), DNSSEC validation is applied as usual — under the condition that it is enabled for the
 373         network and for <filename>systemd-resolved.service</filename> as a whole. If false, DNSSEC validation
 374         is disabled for the specific query, regardless of whether it is enabled for the network or in the
 375         service. Note that setting this option to true does not force DNSSEC validation on systems/networks
 376         where DNSSEC is turned off. This option is only suitable to turn off such validation where otherwise
 377         enabled, not enable validation where otherwise disabled.</para>
 378
 379         <xi:include href="version-info.xml" xpointer="v248"/></listitem>
 380       </varlistentry>
 381
 382       <varlistentry>
 383         <term><option>--synthesize=<replaceable>BOOL</replaceable></option></term>
 384
 385         <listitem><para>Takes a boolean parameter; used in conjunction with <command>query</command>. If true
 386         (the default), select domains are resolved on the local system, among them
 387         <literal>localhost</literal>, <literal>_gateway</literal>, <literal>_outbound</literal>,
 388         <literal>_localdnsstub</literal> and <literal>_localdnsproxy</literal> or entries from
 389         <filename>/etc/hosts</filename>. If false these domains are not resolved locally, and either fail (in
 390         case of <literal>localhost</literal>, <literal>_gateway</literal> or <literal>_outbound</literal> and
 391         suchlike) or go to the network via regular DNS/mDNS/LLMNR lookups (in case of
 392         <filename>/etc/hosts</filename> entries).</para>
 393
 394         <xi:include href="version-info.xml" xpointer="v248"/></listitem>
 395       </varlistentry>
 396
 397       <varlistentry>
 398         <term><option>--cache=<replaceable>BOOL</replaceable></option></term>
 399
 400         <listitem><para>Takes a boolean parameter; used in conjunction with <command>query</command>. If true
 401         (the default), lookups use the local DNS resource record cache. If false, lookups are routed to the
 402         network instead, regardless if already available in the local cache.</para>
 403
 404         <xi:include href="version-info.xml" xpointer="v248"/></listitem>
 405       </varlistentry>
 406
 407       <varlistentry>
 408         <term><option>--zone=<replaceable>BOOL</replaceable></option></term>
 409
 410         <listitem><para>Takes a boolean parameter; used in conjunction with <command>query</command>. If true
 411         (the default), lookups are answered from locally registered LLMNR or mDNS resource records, if
 412         defined. If false, locally registered LLMNR/mDNS records are not considered for the lookup
 413         request.</para>
 414
 415         <xi:include href="version-info.xml" xpointer="v248"/></listitem>
 416       </varlistentry>
 417
 418       <varlistentry>
 419         <term><option>--trust-anchor=<replaceable>BOOL</replaceable></option></term>
 420
 421         <listitem><para>Takes a boolean parameter; used in conjunction with <command>query</command>. If true
 422         (the default), lookups for DS and DNSKEY are answered from the local DNSSEC trust anchors if
 423         possible. If false, the local trust store is not considered for the lookup request.</para>
 424
 425         <xi:include href="version-info.xml" xpointer="v248"/></listitem>
 426       </varlistentry>
 427
 428       <varlistentry>
 429         <term><option>--network=<replaceable>BOOL</replaceable></option></term>
 430
 431         <listitem><para>Takes a boolean parameter; used in conjunction with <command>query</command>. If true
 432         (the default), lookups are answered via DNS, LLMNR or mDNS network requests if they cannot be
 433         synthesized locally, or be answered from the local cache, zone or trust anchors (see above). If false,
 434         the request is not answered from the network and will thus fail if none of the indicated sources can
 435         answer them.</para>
 436
 437         <xi:include href="version-info.xml" xpointer="v248"/></listitem>
 438       </varlistentry>
 439
 440       <varlistentry>
 441         <term><option>--search=<replaceable>BOOL</replaceable></option></term>
 442
 443         <listitem><para>Takes a boolean parameter. If true (the default), any specified single-label
 444         hostnames will be searched in the domains configured in the search domain list, if it is
 445         non-empty. Otherwise, the search domain logic is disabled. Note that this option has no effect if
 446         <option>--type=</option> is used (see above), in which case the search domain logic is
 447         unconditionally turned off.</para>
 448
 449         <xi:include href="version-info.xml" xpointer="v239"/></listitem>
 450       </varlistentry>
 451
 452       <varlistentry>
 453         <term><option>--raw</option><optional>=payload|packet</optional></term>
 454
 455         <listitem><para>Dump the answer as binary data. If there is no argument or if the argument is
 456         <literal>payload</literal>, the payload of the packet is exported. If the argument is
 457         <literal>packet</literal>, the whole packet is dumped in wire format, prefixed by
 458         length specified as a little-endian 64-bit number. This format allows multiple packets
 459         to be dumped and unambiguously parsed.</para>
 460
 461         <xi:include href="version-info.xml" xpointer="v239"/></listitem>
 462       </varlistentry>
 463
 464       <varlistentry>
 465         <term><option>--legend=<replaceable>BOOL</replaceable></option></term>
 466
 467         <listitem><para>Takes a boolean parameter. If true (the default), column headers and meta information about the
 468         query response are shown. Otherwise, this output is suppressed.</para>
 469
 470         <xi:include href="version-info.xml" xpointer="v239"/></listitem>
 471       </varlistentry>
 472
 473       <varlistentry>
 474         <term><option>--stale-data=<replaceable>BOOL</replaceable></option></term>
 475
 476         <listitem><para>Takes a boolean parameter; used in conjunction with <command>query</command>. If true
 477         (the default), lookups are answered with stale data (expired resource records) if
 478         possible. If false, the stale data is not considered for the lookup request.</para>
 479
 480         <xi:include href="version-info.xml" xpointer="v254"/></listitem>
 481       </varlistentry>
 482
 483       <varlistentry>
 484         <term><option>--relax-single-label=<replaceable>BOOL</replaceable></option></term>
 485
 486         <listitem><para>Takes a boolean parameter; used in conjunction with <command>query</command>. If
 487         true, rules regarding routing of single-label names are relaxed. Defaults to false. By default,
 488         lookups of single label names are assumed to refer to local hosts to be resolved via local resolution
 489         such as LLMNR or via search domain qualification and are not routed to upstream servers as is. If
 490         this option is enabled these rules are disabled and the queries are routed upstream anyway. Also see
 491         the <varname>ResolveUnicastSingleLabel=</varname> option in
 492         <citerefentry><refentrytitle>resolved.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 493         which provides a system-wide option that controls this behaviour.</para>
 494
 495         <xi:include href="version-info.xml" xpointer="v256"/></listitem>
 496       </varlistentry>
 497
 498       <xi:include href="standard-options.xml" xpointer="json" />
 499       <xi:include href="standard-options.xml" xpointer="j" />
 500       <xi:include href="standard-options.xml" xpointer="no-pager" />
 501       <xi:include href="standard-options.xml" xpointer="help" />
 502       <xi:include href="standard-options.xml" xpointer="version" />
 503     </variablelist>
 504   </refsect1>
 505
 506   <refsect1>
 507     <title>Compatibility with
 508     <citerefentry project="debian"><refentrytitle>resolvconf</refentrytitle><manvolnum>8</manvolnum></citerefentry></title>
 509
 510     <para><command>resolvectl</command> is a multi-call binary. When invoked as <literal>resolvconf</literal>
 511     (generally achieved by means of a symbolic link of this name to the <command>resolvectl</command> binary) it
 512     is run in a limited
 513     <citerefentry project="debian"><refentrytitle>resolvconf</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 514     compatibility mode. It accepts mostly the same arguments and pushes all data into
 515     <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 516     similar to how <option>dns</option> and <option>domain</option> commands operate. Note that
 517     <command>systemd-resolved.service</command> is the only supported backend, which is different from other
 518     implementations of this command.</para>
 519
 520     <para><filename>/etc/resolv.conf</filename> will only be updated with servers added with this command
 521     when <filename>/etc/resolv.conf</filename> is a symlink to
 522     <filename>/run/systemd/resolve/resolv.conf</filename>, and not a static file. See the discussion of
 523     <filename>/etc/resolv.conf</filename> handling in
 524     <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
 525     </para>
 526
 527     <para>Not all operations supported by other implementations are supported natively. Specifically:</para>
 528
 529     <variablelist>
 530       <varlistentry>
 531         <term><option>-a</option></term>
 532         <listitem><para>Registers per-interface DNS configuration data with
 533         <command>systemd-resolved</command>. Expects a network interface name as only command line argument. Reads
 534         <citerefentry project='man-pages'><refentrytitle>resolv.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>-compatible
 535         DNS configuration data from its standard input. Relevant fields are <literal>nameserver</literal> and
 536         <literal>domain</literal>/<literal>search</literal>. This command is mostly identical to invoking
 537         <command>resolvectl</command> with a combination of <option>dns</option> and <option>domain</option>
 538         commands.</para>
 539
 540         <xi:include href="version-info.xml" xpointer="v239"/></listitem>
 541       </varlistentry>
 542
 543       <varlistentry>
 544         <term><option>-d</option></term>
 545         <listitem><para>Unregisters per-interface DNS configuration data with <command>systemd-resolved</command>. This
 546         command is mostly identical to invoking <command>resolvectl revert</command>.</para>
 547
 548         <xi:include href="version-info.xml" xpointer="v239"/></listitem>
 549       </varlistentry>
 550
 551       <varlistentry>
 552         <term><option>-f</option></term>
 553
 554         <listitem><para>When specified <option>-a</option> and <option>-d</option> will not complain about missing
 555         network interfaces and will silently execute no operation in that case.</para>
 556
 557         <xi:include href="version-info.xml" xpointer="v239"/></listitem>
 558       </varlistentry>
 559
 560       <varlistentry>
 561         <term><option>-x</option></term>
 562
 563         <listitem><para>This switch for "exclusive" operation is supported only partially. It is mapped to an
 564         additional configured search domain of <literal>~.</literal> — i.e. ensures that DNS traffic is preferably
 565         routed to the DNS servers on this interface, unless there are other, more specific domains configured on other
 566         interfaces.</para>
 567
 568         <xi:include href="version-info.xml" xpointer="v239"/></listitem>
 569       </varlistentry>
 570
 571       <varlistentry>
 572         <term><option>-m</option></term>
 573         <term><option>-p</option></term>
 574
 575         <listitem><para>These switches are not supported and are silently ignored.</para>
 576
 577         <xi:include href="version-info.xml" xpointer="v239"/></listitem>
 578       </varlistentry>
 579
 580       <varlistentry>
 581         <term><option>-u</option></term>
 582         <term><option>-I</option></term>
 583         <term><option>-i</option></term>
 584         <term><option>-l</option></term>
 585         <term><option>-R</option></term>
 586         <term><option>-r</option></term>
 587         <term><option>-v</option></term>
 588         <term><option>-V</option></term>
 589         <term><option>--enable-updates</option></term>
 590         <term><option>--disable-updates</option></term>
 591         <term><option>--are-updates-enabled</option></term>
 592
 593         <listitem><para>These switches are not supported and the command will fail if used.</para>
 594
 595         <xi:include href="version-info.xml" xpointer="v239"/></listitem>
 596       </varlistentry>
 597
 598     </variablelist>
 599
 600     <para>See
 601     <citerefentry project="debian"><refentrytitle>resolvconf</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 602     for details on those command line options.</para>
 603   </refsect1>
 604
 605   <refsect1>
 606     <title>Examples</title>
 607
 608     <example>
 609       <title>Retrieve the addresses of the <literal>www.0pointer.net</literal> domain (<constant class='dns'>A</constant> and <constant class='dns'>AAAA</constant> resource records)</title>
 610
 611       <programlisting>$ resolvectl query www.0pointer.net
 612 www.0pointer.net: 2a01:238:43ed:c300:10c3:bcf3:3266:da74
 613                   85.214.157.71
 614
 615 -- Information acquired via protocol DNS in 611.6ms.
 616 -- Data is authenticated: no
 617 </programlisting>
 618     </example>
 619
 620     <example>
 621       <title>Retrieve the domain of the <literal>85.214.157.71</literal> IP address
 622       (<constant class='dns'>PTR</constant> resource record)</title>
 623
 624       <programlisting>$ resolvectl query 85.214.157.71
 625 85.214.157.71: gardel.0pointer.net
 626
 627 -- Information acquired via protocol DNS in 1.2997s.
 628 -- Data is authenticated: no
 629 </programlisting>
 630     </example>
 631
 632     <example>
 633       <title>Retrieve the <constant class='dns'>MX</constant> record of the <literal>yahoo.com</literal>
 634       domain</title>
 635
 636       <programlisting>$ resolvectl --legend=no -t MX query yahoo.com
 637 yahoo.com. IN MX    1 mta7.am0.yahoodns.net
 638 yahoo.com. IN MX    1 mta6.am0.yahoodns.net
 639 yahoo.com. IN MX    1 mta5.am0.yahoodns.net
 640 </programlisting>
 641     </example>
 642
 643     <example>
 644       <title>Resolve an <constant class='dns'>SRV</constant> service</title>
 645
 646       <programlisting>$ resolvectl service _xmpp-server._tcp gmail.com
 647 _xmpp-server._tcp/gmail.com: alt1.xmpp-server.l.google.com:5269 [priority=20, weight=0]
 648                              173.194.210.125
 649                              alt4.xmpp-server.l.google.com:5269 [priority=20, weight=0]
 650                              173.194.65.125
 651                              …
 652 </programlisting>
 653     </example>
 654
 655     <example>
 656       <title>Retrieve a PGP key (<constant class='dns'>OPENPGP</constant> resource record)</title>
 657
 658       <programlisting>$ resolvectl openpgp zbyszek@fedoraproject.org
 659 d08ee310438ca124a6149ea5cc21b6313b390dce485576eff96f8722._openpgpkey.fedoraproject.org. IN OPENPGPKEY
 660         mQINBFBHPMsBEACeInGYJCb+7TurKfb6wGyTottCDtiSJB310i37/6ZYoeIay/5soJjlMyf
 661         MFQ9T2XNT/0LM6gTa0MpC1st9LnzYTMsT6tzRly1D1UbVI6xw0g0vE5y2Cjk3xUwAynCsSs
 662         …
 663 </programlisting>
 664     </example>
 665
 666     <example>
 667       <title>Retrieve a TLS key (<constant class='dns'>TLSA</constant> resource record)</title>
 668
 669       <programlisting>$ resolvectl tlsa tcp fedoraproject.org:443
 670 _443._tcp.fedoraproject.org IN TLSA 0 0 1 19400be5b7a31fb733917700789d2f0a2471c0c9d506c0e504c06c16d7cb17c0
 671         -- Cert. usage: CA constraint
 672         -- Selector: Full Certificate
 673         -- Matching type: SHA-256
 674 </programlisting>
 675
 676       <para><literal>tcp</literal> and <literal>:443</literal> are optional and could be skipped.</para>
 677     </example>
 678   </refsect1>
 679
 680   <refsect1>
 681     <title>See Also</title>
 682     <para><simplelist type="inline">
 683       <member><citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
 684       <member><citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry></member>
 685       <member><citerefentry><refentrytitle>systemd.dnssd</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
 686       <member><citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry></member>
 687       <member><citerefentry><refentrytitle>resolvconf</refentrytitle><manvolnum>8</manvolnum></citerefentry></member>
 688     </simplelist></para>
 689   </refsect1>
 690 </refentry>