systemd-resolve(1)



SYSTEMD-RESOLVE(1)              systemd-resolve             SYSTEMD-RESOLVE(1)

NAME
       systemd-resolve - Resolve domain names, IPV4 and IPv6 addresses, DNS
       resource records, and services

SYNOPSIS
       systemd-resolve [OPTIONS...] HOSTNAME...

       systemd-resolve [OPTIONS...] ADDRESS...

       systemd-resolve [OPTIONS...] --type=TYPE DOMAIN...

       systemd-resolve [OPTIONS...] --service [[NAME] TYPE] DOMAIN

       systemd-resolve [OPTIONS...] --openpgp USER@DOMAIN

       systemd-resolve [OPTIONS...] --tlsa DOMAIN[:PORT]

       systemd-resolve [OPTIONS...] --statistics

       systemd-resolve [OPTIONS...] --reset-statistics

DESCRIPTION
       systemd-resolve 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.

       The --type= switch may be used to specify a DNS resource record type
       (A, AAAA, SOA, MX, ...) in order to request a specific DNS resource
       record, instead of the address or reverse address lookups. The special
       value "help" may be used to list known values.

       The --service switch may be used to resolve SRV[1] and DNS-SD[2]
       services (see below). In this mode, between one and three arguments are
       required. 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).

       The --openpgp switch may be used to query PGP keys stored as
       OPENPGPKEY[3] resource records. When this option is specified one or
       more e-mail address must be specified.

       The --tlsa switch maybe be used to query TLS public keys stored as
       TLSA[4] resource records. When this option is specified one or more
       domain names must be specified.

       The --statistics switch may be used to show resolver statistics,
       including information about the number of successful and failed DNSSEC
       validations.

       The --reset-statistics may be used to reset various statistics counters
       maintained the resolver, including those shown in the --statistics
       output. This operation requires root privileges.

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[5]), "llmnr-ipv4", "llmnr-ipv6" (LLMNR via the indicated
           underlying IP protocols), "mdns" (Multicast DNS[6]), "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
           Enables service resolution. This enables DNS-SD and simple SRV
           service resolution, depending on the specified list of parameters
           (see above).

       --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.

       --openpgp
           Enables OPENPGPKEY resource record resolution (see above).
           Specified e-mail addresses are converted to the corresponding DNS
           domain name, and any OPENPGPKEY keys are printed.

       --tlsa
           Enables TLSA resource record resolution (see above). 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 an argument after --tlsa,
           otherwise tcp will be used.

       --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.

       --statistics
           If specified general resolver statistics are shown, 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.

       --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.

       --status
           Shows the global and per-link DNS settings in currently in effect.

       --set-dns=SERVER, --set-domain=DOMAIN, --set-llmnr=MODE,
       --set-mdns=MODE, --set-dnssec=MODE, --set-nta=DOMAIN
           Set per-interface DNS configuration. These switches 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 switches may be used to inform
           systemd-resolved about per-interface DNS configuration determined
           through external means. Multiple of these switches may be passed on
           a single invocation of systemd-resolve in order to set multiple
           configuration options at once. If any of these switches is used, it
           must be combined with --interface= to indicate the network
           interface the new DNS configuration belongs to. The --set-dns=
           option expects an IPv4 or IPv6 address specification of a DNS
           server to use, and may be used multiple times to define multiple
           servers for the same interface. The --set-domain= option expects a
           valid DNS domain, possibly prefixed with "~", and configures a
           per-interface search or route-only domain. It may be used multiple
           times to configure multiple such domains. The --set-llmnr=,
           --set-mdns= and --set-dnssec= options may be used to configure the
           per-interface LLMNR, MulticastDNS and DNSSEC settings. Finally,
           --set-nta= may be used to configure additional per-interface DNSSEC
           NTA domains and may also be used multiple times. For details about
           these settings, their possible values and their effect, see the
           corresponding options in systemd.network(5).

       --revert
           Revert the per-interface DNS configuration. This option must be
           combined with --interface= to indicate the network interface the
           DNS configuration shall be reverted on. If the DNS configuration is
           reverted all per-interface DNS setting are reset to their defaults,
           undoing all effects of --set-dns=, --set-domain=, --set-llmnr=,
           --set-mdns=, --set-dnssec=, --set-nta=. Note that when a network
           interface disappears all configuration is lost automatically, an
           explicit reverting is not necessary in that case.

       -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.

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

           $ systemd-resolve 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

           $ systemd-resolve 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

           $ systemd-resolve -t MX yahoo.com --legend=no
           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

           $ systemd-resolve --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

           $ systemd-resolve --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)

           $ systemd-resolve --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)

NOTES
        1. SRV
           https://tools.ietf.org/html/rfc2782

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

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

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

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

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

systemd 237                                                 SYSTEMD-RESOLVE(1)

Man(1) output converted with man2html
list of all man pages