NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXAMPLES | SEE ALSO | NOTES | COLOPHON

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

NAME         top

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

SYNOPSIS         top

       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         top

       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         top

       -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.

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

       -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         top

       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         top

       systemd(1), systemd-resolved.service(8)

NOTES         top

        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

COLOPHON         top

       This page is part of the systemd (systemd system and service manager)
       project.  Information about the project can be found at 
       ⟨http://www.freedesktop.org/wiki/Software/systemd⟩.  If you have a bug
       report for this manual page, see
       ⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.  This
       page was obtained from the project's upstream Git repository
       ⟨https://github.com/systemd/systemd.git⟩ on 2017-11-25.  (At that
       time, the date of the most recent commit that was found in the repos‐
       itory was 2017-11-24.)  If you discover any rendering problems in
       this HTML version of the page, or you believe there is a better or
       more up-to-date source for the page, or you have corrections or
       improvements to the information in this COLOPHON (which is not part
       of the original manual page), send a mail to man-pages@man7.org

systemd 234                                               SYSTEMD-RESOLVE(1)

Pages that refer to this page: systemd.directives(7)systemd.index(7)systemd-resolved.service(8)