Manual: resolvectl
RESOLVECTL(1) resolvectl RESOLVECTL(1)
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
addresses 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" hostname
or all data from /etc/hosts.
COMMANDS
query HOSTNAME|ADDRESS...
Resolve domain names, as well as IPv4 and IPv6 addresses. When used in conjunction with --type= or --class= (see
below), resolves low-level DNS resource records.
If a single-label domain name is specified it is searched for according to the configured search domains — unless
--search=no or --type=/--class= are specified, both of which turn this logic off.
If an international domain name is specified, it is automatically translated according to IDNA rules when
resolved via classic DNS — but not for look-ups via MulticastDNS or LLMNR. If --type=/--class= is used IDNA
translation is turned off and domain names are processed as specified.
If combined with --json= (only supported in combination with --type=) will output the resource record data in a
JSON object.
Added in version 239.
service [[NAME] TYPE] DOMAIN
Resolve RFC 6763 DNS-SD[1] and RFC 2782 SRV[2] 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 resource record 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).
Added in version 239.
openpgp EMAIL@DOMAIN...
Query PGP keys stored as OPENPGPKEY resource records, see RFC 7929[3]. Specified e-mail addresses are converted
to the corresponding DNS domain name, and any OPENPGPKEY keys are printed.
Added in version 239.
tlsa [FAMILY] DOMAIN[:PORT]...
Query TLS public keys stored as TLSA resource records, see RFC 6698[4]. 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.
Added in version 239.
status [LINK...]
Shows the global and per-link DNS settings currently in effect. If no command is specified, this is the implied
default.
Added in version 239.
statistics
Shows general resolver statistics, including information whether DNSSEC is enabled and available, as well as
resolution and validation statistics.
Added in version 239.
reset-statistics
Resets the statistics counters shown in statistics to zero. This operation requires root privileges.
Added in version 239.
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.
Added in version 239.
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.
Added in version 239.
dns [LINK [SERVER...]], domain [LINK [DOMAIN...]], default-route [LINK [BOOL...]], 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. These commands may be used to inform systemd-resolved or systemd-networkd about per-interface DNS
configuration determined through external means. The dns command expects IPv4 or IPv6 address specifications of
DNS servers to use. Each address can optionally take a port number separated with ":", a network interface name
or index separated with "%", and a Server Name Indication (SNI) separated with "#". When IPv6 address is
specified with a port number, then the address must be in the square brackets. That is, the acceptable full
formats are "111.222.333.444:9953%ifname#example.com" for IPv4 and "[1111:2222::3333]:9953%ifname#example.com"
for IPv6. The domain command expects valid DNS domains, possibly prefixed with "~", and configures a
per-interface search or route-only domain. The default-route command expects a boolean parameter, and configures
whether the link may be used as default route for DNS lookups, i.e. if it is suitable for lookups on domains no
other link explicitly is configured for. 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.
Commands dns, domain and nta can take a single empty string argument to clear their respective value lists.
For details about these settings, their possible values and their effect, see the corresponding settings in
systemd.network(5).
Added in version 239.
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, default-route, 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.
Added in version 239.
monitor
Show a continuous stream of local client resolution queries and their responses. Whenever a local query is
completed the query's DNS resource lookup key and resource records are shown. Note that this displays queries
issued locally only, and does not immediately relate to DNS requests submitted to configured DNS servers or the
LLMNR or MulticastDNS zones, as lookups may be answered from the local cache, or might result in multiple DNS
transactions (for example to validate DNSSEC information). If CNAME/CNAME redirection chains are followed, a
separate query will be displayed for each element of the chain. Use --json= to enable JSON output.
Added in version 252.
show-cache
Show current cache content, per scope. Use --json= to enable JSON output.
Added in version 254.
show-server-state
Show detailed server state information, per DNS Server. Use --json= to enable JSON output.
Added in version 255.
log-level [LEVEL]
If no argument is given, print the current log level of the manager. If an optional argument LEVEL is provided,
then the command changes the current log level of the manager to LEVEL (accepts the same values as --log-level=
described in systemd(1)).
Added in version 244.
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.
Added in version 239.
-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/resolved.conf) in place of per-link
configuration is used.
Added in version 239.
-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.
Added in version 239.
-t TYPE, --type=TYPE, -c CLASS, --class=CLASS
When used in conjunction with the query command, 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.
Without these options resolvectl query provides high-level domain name to address and address to domain name
resolution. With these options it provides low-level DNS resource record resolution. The search domain logic is
automatically turned off when these options are used, i.e. specified domain names need to be fully qualified
domain names. Moreover, IDNA internal domain name translation is turned off as well, i.e. international domain
names should be specified in "xn--..." notation, unless look-up in MulticastDNS/LLMNR is desired, in which case
UTF-8 characters should be used.
Added in version 239.
--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.
Added in version 239.
--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.
Added in version 239.
--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.
Added in version 239.
--validate=BOOL
Takes a boolean parameter; used in conjunction with query. If true (the default), DNSSEC validation is applied as
usual — under the condition that it is enabled for the network and for systemd-resolved.service as a whole. If
false, DNSSEC validation is disabled for the specific query, regardless of whether it is enabled for the network
or in the service. Note that setting this option to true does not force DNSSEC validation on systems/networks
where DNSSEC is turned off. This option is only suitable to turn off such validation where otherwise enabled, not
enable validation where otherwise disabled.
Added in version 248.
--synthesize=BOOL
Takes a boolean parameter; used in conjunction with query. If true (the default), select domains are resolved on
the local system, among them "localhost", "_gateway", "_outbound", "_localdnsstub" and "_localdnsproxy" or
entries from /etc/hosts. If false these domains are not resolved locally, and either fail (in case of
"localhost", "_gateway" or "_outbound" and suchlike) or go to the network via regular DNS/mDNS/LLMNR lookups (in
case of /etc/hosts entries).
Added in version 248.
--cache=BOOL
Takes a boolean parameter; used in conjunction with query. If true (the default), lookups use the local DNS
resource record cache. If false, lookups are routed to the network instead, regardless of whether already
available in the local cache.
Added in version 248.
--zone=BOOL
Takes a boolean parameter; used in conjunction with query. If true (the default), lookups are answered from
locally registered LLMNR or mDNS resource records, if defined. If false, locally registered LLMNR/mDNS records
are not considered for the lookup request.
Added in version 248.
--trust-anchor=BOOL
Takes a boolean parameter; used in conjunction with query. If true (the default), lookups for DS and DNSKEY are
answered from the local DNSSEC trust anchors if possible. If false, the local trust store is not considered for
the lookup request.
Added in version 248.
--network=BOOL
Takes a boolean parameter; used in conjunction with query. If true (the default), lookups are answered via DNS,
LLMNR or mDNS network requests if they cannot be synthesized locally, or be answered from the local cache, zone
or trust anchors (see above). If false, the request is not answered from the network and will thus fail if none
of the indicated sources can answer them.
Added in version 248.
--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.
Note that this option has no effect if --type= is used (see above), in which case the search domain logic is
unconditionally turned off.
Added in version 239.
--raw[=payload|packet]
Dump the answer records as binary data. If there is no argument or if the argument is "payload", the payload of
the resource record data is exported, i.e. not the whole "RDATA", but just primary contents. If the argument is
"packet", the whole resource record is dumped in wire format, prefixed by length specified as a little-endian
64-bit integer. This format allows multiple record to be dumped and unambiguously parsed.
Note that "payload" is only supported for a small subset of resource record types: SSHFP, TLSA, OPENPGPKEY where
this dumps the key material only; and A, AAAA where this dumps the address data.
Added in version 239.
--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.
Added in version 239.
--stale-data=BOOL
Takes a boolean parameter; used in conjunction with query. If true (the default), lookups are answered with stale
data (expired resource records) if possible. If false, the stale data is not considered for the lookup request.
Added in version 254.
--relax-single-label=BOOL
Takes a boolean parameter; used in conjunction with query. If true, rules regarding routing of single-label names
are relaxed. Defaults to false. By default, lookups of single-label names are assumed to refer to local hosts to
be resolved via local resolution such as LLMNR or via search domain qualification and are not routed to upstream
servers as is. If this option is enabled these rules are disabled and the queries are routed upstream anyway.
Also see the ResolveUnicastSingleLabel= option in resolved.conf(5) which provides a system-wide option that
controls this behaviour.
Added in version 256.
--no-ask-password
Do not query the user for authentication for privileged operations.
--json=MODE
Shows output formatted as JSON. Expects one of "short" (for the shortest possible output without any redundant
whitespace or line breaks), "pretty" (for a pretty version of the same, with indentation and line breaks) or
"off" (to turn off JSON output, the default).
-j
Equivalent to --json=pretty if running on a terminal, and --json=short otherwise.
--no-pager
Do not pipe output into a pager.
-h, --help
Print a short help text and exit.
--version
Print a short version string and exit.
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.
/etc/resolv.conf will only be updated with servers added with this command when /etc/resolv.conf is a symlink to
/run/systemd/resolve/resolv.conf, and not a static file. See the discussion of /etc/resolv.conf handling in systemd-
resolved.service(8).
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.
Added in version 239.
-d
Unregisters per-interface DNS configuration data with systemd-resolved. This command is mostly identical to
invoking resolvectl revert.
Added in version 239.
-f
When specified -a and -d will not complain about missing network interfaces and will silently execute no
operation in that case.
Added in version 239.
-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.
Added in version 239.
-p
When specified, the interface will not be used as the default route. See also systemd-resolved.service(8) about
the default route.
Added in version 257.
-m
The switch is not supported and is silently ignored.
Added in version 239.
-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.
Added in version 239.
See resolvconf(8) for details on those command line options.
EXAMPLES
Example 1. Retrieve the addresses of the "www.0pointer.net" domain (A and AAAA resource records)
$ 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 (PTR resource record)
$ 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 (OPENPGP resource record)
$ resolvectl openpgp zbyszek@fedoraproject.org
d08ee310438ca124a6149ea5cc21b6313b390dce485576eff96f8722._openpgpkey.fedoraproject.org. IN OPENPGPKEY
mQINBFBHPMsBEACeInGYJCb+7TurKfb6wGyTottCDtiSJB310i37/6ZYoeIay/5soJjlMyf
MFQ9T2XNT/0LM6gTa0MpC1st9LnzYTMsT6tzRly1D1UbVI6xw0g0vE5y2Cjk3xUwAynCsSs
...
Example 6. Retrieve a TLS key (TLSA resource record)
$ 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
"tcp" and ":443" are optional and could be skipped.
SEE ALSO
systemd(1), systemd-resolved.service(8), systemd.dnssd(5), systemd-networkd.service(8), resolvconf(8)
NOTES
1. RFC 6763 DNS-SD
https://tools.ietf.org/html/rfc6763
2. RFC 2782 SRV
https://tools.ietf.org/html/rfc2782
3. RFC 7929
https://tools.ietf.org/html/rfc7929
4. RFC 6698
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 259.5 RESOLVECTL(1)