Provided by: systemd_239-7ubuntu10_amd64 bug

NAME

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

SYNOPSIS

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

DESCRIPTION

       resolvectl may be used to resolve domain names, IPv4 and IPv6 addresses, DNS resource
       records and services with the systemd-resolved.service(8) resolver service. By default,
       the specified list of parameters will be resolved as hostnames, retrieving their IPv4 and
       IPv6 addresses. If the parameters specified are formatted as IPv4 or IPv6 operation the
       reverse operation is done, and a hostname is retrieved for the specified addresses.

       The program's output contains information about the protocol used for the look-up and on
       which network interface the data was discovered. It also contains information on whether
       the information could be authenticated. All data for which local DNSSEC validation
       succeeds is considered authenticated. Moreover all data originating from local, trusted
       sources is also reported authenticated, including resolution of the local host name, the
       "localhost" host name or all data from /etc/hosts.

OPTIONS

       -4, -6
           By default, when resolving a hostname, both IPv4 and IPv6 addresses are acquired. By
           specifying -4 only IPv4 addresses are requested, by specifying -6 only IPv6 addresses
           are requested.

       -i INTERFACE, --interface=INTERFACE
           Specifies the network interface to execute the query on. This may either be specified
           as numeric interface index or as network interface string (e.g.  "en0"). Note that
           this option has no effect if system-wide DNS configuration (as configured in
           /etc/resolv.conf or /etc/systemd/resolve.conf) in place of per-link configuration is
           used.

       -p PROTOCOL, --protocol=PROTOCOL
           Specifies the network protocol for the query. May be one of "dns" (i.e. classic
           unicast DNS), "llmnr" (Link-Local Multicast Name Resolution[1]), "llmnr-ipv4",
           "llmnr-ipv6" (LLMNR via the indicated underlying IP protocols), "mdns" (Multicast
           DNS[2]), "mdns-ipv4", "mdns-ipv6" (MDNS via the indicated underlying IP protocols). By
           default the lookup is done via all protocols suitable for the lookup. If used, limits
           the set of protocols that may be used. Use this option multiple times to enable
           resolving via multiple protocols at the same time. The setting "llmnr" is identical to
           specifying this switch once with "llmnr-ipv4" and once via "llmnr-ipv6". Note that
           this option does not force the service to resolve the operation with the specified
           protocol, as that might require a suitable network interface and configuration. The
           special value "help" may be used to list known values.

       -t TYPE, --type=TYPE, -c CLASS, --class=CLASS
           Specifies the DNS resource record type (e.g. A, AAAA, MX, ...) and class (e.g. IN,
           ANY, ...) to look up. If these options are used a DNS resource record set matching the
           specified class and type is requested. The class defaults to IN if only a type is
           specified. The special value "help" may be used to list known values.

       --service-address=BOOL
           Takes a boolean parameter. If true (the default), when doing a service lookup with
           --service the hostnames contained in the SRV resource records are resolved as well.

       --service-txt=BOOL
           Takes a boolean parameter. If true (the default), when doing a DNS-SD service lookup
           with --service the TXT service metadata record is resolved as well.

       --cname=BOOL
           Takes a boolean parameter. If true (the default), DNS CNAME or DNAME redirections are
           followed. Otherwise, if a CNAME or DNAME record is encountered while resolving, an
           error is returned.

       --search=BOOL
           Takes a boolean parameter. If true (the default), any specified single-label hostnames
           will be searched in the domains configured in the search domain list, if it is
           non-empty. Otherwise, the search domain logic is disabled.

       --raw[=payload|packet]
           Dump the answer as binary data. If there is no argument or if the argument is
           "payload", the payload of the packet is exported. If the argument is "packet", the
           whole packet is dumped in wire format, prefixed by length specified as a little-endian
           64-bit number. This format allows multiple packets to be dumped and unambiguously
           parsed.

       --legend=BOOL
           Takes a boolean parameter. If true (the default), column headers and meta information
           about the query response are shown. Otherwise, this output is suppressed.

       -h, --help
           Print a short help text and exit.

       --version
           Print a short version string and exit.

       --no-pager
           Do not pipe output into a pager.

COMMANDS

       query HOSTNAME|ADDRESS...
           Resolve domain names, IPv4 and IPv6 addresses.

       service [[NAME] TYPE] DOMAIN
           Resolve DNS-SD[3] and SRV[4] services, depending on the specified list of parameters.
           If three parameters are passed the first is assumed to be the DNS-SD service name, the
           second the SRV service type, and the third the domain to search in. In this case a
           full DNS-SD style SRV and TXT lookup is executed. If only two parameters are
           specified, the first is assumed to be the SRV service type, and the second the domain
           to look in. In this case no TXT RR is requested. Finally, if only one parameter is
           specified, it is assumed to be a domain name, that is already prefixed with an SRV
           type, and an SRV lookup is done (no TXT).

       openpgp EMAIL@DOMAIN...
           Query PGP keys stored as OPENPGPKEY[5] resource records. Specified e-mail addresses
           are converted to the corresponding DNS domain name, and any OPENPGPKEY keys are
           printed.

       tlsa [FAMILY] DOMAIN[:PORT]...
           Query TLS public keys stored as TLSA[6] resource records. A query will be performed
           for each of the specified names prefixed with the port and family
           ("_port._family.domain"). The port number may be specified after a colon (":"),
           otherwise 443 will be used by default. The family may be specified as the first
           argument, otherwise tcp will be used.

       status [LINK...]
           Shows the global and per-link DNS settings in currently in effect. If no command is
           specified, this is the implied default.

       statistics
           Shows general resolver statistics, including information whether DNSSEC is enabled and
           available, as well as resolution and validation statistics.

       reset-statistics
           Resets the statistics counters shown in statistics to zero. This operation requires
           root privileges.

       flush-caches
           Flushes all DNS resource record caches the service maintains locally. This is mostly
           equivalent to sending the SIGUSR2 to the systemd-resolved service.

       reset-server-features
           Flushes all feature level information the resolver learnt about specific servers, and
           ensures that the server feature probing logic is started from the beginning with the
           next look-up request. This is mostly equivalent to sending the SIGRTMIN+1 to the
           systemd-resolved service.

       dns [LINK [SERVER...]], domain [LINK [DOMAIN...]], llmnr [LINK [MODE]], mdns [LINK
       [MODE]], dnssec [LINK [MODE]], dnsovertls [LINK [MODE]], nta [LINK [DOMAIN...]]
           Get/set per-interface DNS configuration. These commands may be used to configure
           various DNS settings for network interfaces that aren't managed by systemd-
           networkd.service(8). (These commands will fail when used on interfaces that are
           managed by systemd-networkd, please configure their DNS settings directly inside the
           .network files instead.) These commands may be used to inform systemd-resolved about
           per-interface DNS configuration determined through external means. The dns command
           expects IPv4 or IPv6 address specifications of DNS servers to use. The domain command
           expects valid DNS domains, possibly prefixed with "~", and configures a per-interface
           search or route-only domain. The llmnr, mdns, dnssec and dnsovertls commands may be
           used to configure the per-interface LLMNR, MulticastDNS, DNSSEC and DNSOverTLS
           settings. Finally, nta command may be used to configure additional per-interface
           DNSSEC NTA domains. For details about these settings, their possible values and their
           effect, see the corresponding options in systemd.network(5).

       revert LINK
           Revert the per-interface DNS configuration. If the DNS configuration is reverted all
           per-interface DNS setting are reset to their defaults, undoing all effects of dns,
           domain, llmnr, mdns, dnssec, dnsovertls, nta. Note that when a network interface
           disappears all configuration is lost automatically, an explicit reverting is not
           necessary in that case.

COMPATIBILITY WITH RESOLVCONF(8)

       resolvectl is a multi-call binary. When invoked as "resolvconf" (generally achieved by
       means of a symbolic link of this name to the resolvectl binary) it is run in a limited
       resolvconf(8) compatibility mode. It accepts mostly the same arguments and pushes all data
       into systemd-resolved.service(8), similar to how dns and domain commands operate. Note
       that systemd-resolved.service is the only supported backend, which is different from other
       implementations of this command. Note that not all operations supported by other
       implementations are supported natively. Specifically:

       -a
           Registers per-interface DNS configuration data with systemd-resolved. Expects a
           network interface name as only command line argument. Reads resolv.conf(5) compatible
           DNS configuration data from its standard input. Relevant fields are "nameserver" and
           "domain"/"search". This command is mostly identical to invoking resolvectl with a
           combination of dns and domain commands.

       -d
           Unregisters per-interface DNS configuration data with systemd-resolved. This command
           is mostly identical to invoking resolvectl revert.

       -f
           When specified -a and -d will not complain about missing network interfaces and will
           silently execute no operation in that case.

       -x
           This switch for "exclusive" operation is supported only partially. It is mapped to an
           additional configured search domain of "~."  — i.e. ensures that DNS traffic is
           preferably routed to the DNS servers on this interface, unless there are other, more
           specific domains configured on other interfaces.

       -m, -p
           These switches are not supported and are silently ignored.

       -u, -I, -i, -l, -R, -r, -v, -V, --enable-updates, --disable-updates, --are-updates-enabled
           These switches are not supported and the command will fail if used.

       See resolvconf(8) for details on this command line options.

EXAMPLES

       Example 1. Retrieve the addresses of the "www.0pointer.net" domain

           $ resolvectl query www.0pointer.net
           www.0pointer.net: 2a01:238:43ed:c300:10c3:bcf3:3266:da74
                             85.214.157.71

           -- Information acquired via protocol DNS in 611.6ms.
           -- Data is authenticated: no

       Example 2. Retrieve the domain of the "85.214.157.71" IP address

           $ resolvectl query 85.214.157.71
           85.214.157.71: gardel.0pointer.net

           -- Information acquired via protocol DNS in 1.2997s.
           -- Data is authenticated: no

       Example 3. Retrieve the MX record of the "yahoo.com" domain

           $ resolvectl --legend=no -t MX query yahoo.com
           yahoo.com. IN MX    1 mta7.am0.yahoodns.net
           yahoo.com. IN MX    1 mta6.am0.yahoodns.net
           yahoo.com. IN MX    1 mta5.am0.yahoodns.net

       Example 4. Resolve an SRV service

           $ resolvectl service _xmpp-server._tcp gmail.com
           _xmpp-server._tcp/gmail.com: alt1.xmpp-server.l.google.com:5269 [priority=20, weight=0]
                                        173.194.210.125
                                        alt4.xmpp-server.l.google.com:5269 [priority=20, weight=0]
                                        173.194.65.125
                                        ...

       Example 5. Retrieve a PGP key

           $ resolvectl openpgp zbyszek@fedoraproject.org
           d08ee310438ca124a6149ea5cc21b6313b390dce485576eff96f8722._openpgpkey.fedoraproject.org. IN OPENPGPKEY
                   mQINBFBHPMsBEACeInGYJCb+7TurKfb6wGyTottCDtiSJB310i37/6ZYoeIay/5soJjlMyf
                   MFQ9T2XNT/0LM6gTa0MpC1st9LnzYTMsT6tzRly1D1UbVI6xw0g0vE5y2Cjk3xUwAynCsSs
                   ...

       Example 6. Retrieve a TLS key ("tcp" and ":443" could be skipped)

           $ resolvectl tlsa tcp fedoraproject.org:443
           _443._tcp.fedoraproject.org IN TLSA 0 0 1 19400be5b7a31fb733917700789d2f0a2471c0c9d506c0e504c06c16d7cb17c0
                   -- Cert. usage: CA constraint
                   -- Selector: Full Certificate
                   -- Matching type: SHA-256

SEE ALSO

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

NOTES

        1. Link-Local Multicast Name Resolution
           https://tools.ietf.org/html/rfc4795

        2. Multicast DNS
           https://www.ietf.org/rfc/rfc6762.txt

        3. DNS-SD
           https://tools.ietf.org/html/rfc6763

        4. SRV
           https://tools.ietf.org/html/rfc2782

        5. OPENPGPKEY
           https://tools.ietf.org/html/rfc7929

        6. TLSA
           https://tools.ietf.org/html/rfc6698