SYSTEMD-RESOLVE(1) systemd-resolve SYSTEMD-RESOLVE(1)
systemd-resolve - Resolve domain names, IPV4 and IPv6 addresses, DNS resource records, and services
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
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 and DNS-SD 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 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 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
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.
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), "llmnr-ipv4", "llmnr-ipv6" (LLMNR via the indicated underlying IP protocols), "mdns" (Multicast DNS), "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.
Enables service resolution. This enables DNS-SD and simple SRV service resolution, depending on the specified list of parameters (see
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.
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.
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.
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.
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.
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.
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.
Takes a boolean parameter. If true (the default), column headers and meta information about the query response are shown. Otherwise,
this output is suppressed.
If specified general resolver statistics are shown, including information whether DNSSEC is enabled and available, as well as
resolution and validation statistics.
Resets the statistics counters shown in --statistics to zero.
Flushes all DNS resource record caches the service maintains locally. This is mostly equivalent to sending the SIGUSR2 to the
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
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 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.
Print a short help text and exit.
Print a short version string and exit.
Do not pipe output into a pager.
Example 1. Retrieve the addresses of the "www.0pointer.net" domain
$ systemd-resolve www.0pointer.net
-- Information acquired via protocol DNS in 611.6ms.
-- Data is authenticated: no
Example 2. Retrieve the domain of the "220.127.116.11" IP address
$ systemd-resolve 18.104.22.168
-- 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]
alt4.xmpp-server.l.google.com:5269 [priority=20, weight=0]
Example 5. Retrieve a PGP key
$ systemd-resolve --openpgp firstname.lastname@example.org
d08ee310438ca124a6149ea5cc21b6313b390dce485576eff96f8722._openpgpkey.fedoraproject.org. IN OPENPGPKEY
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
systemd(1), systemd-resolved.service(8), systemd.dnssd(5), systemd-networkd.service(8)
5. Link-Local Multicast Name Resolution
6. Multicast DNS
systemd 237 SYSTEMD-RESOLVE(1)