resolvectl, resolvconf — Resolve domain names, IPV4 and IPv6 addresses, DNS resource records, and services; introspect and reconfigure the DNS resolver
resolvectl [OPTIONS...] {COMMAND} [NAME...]
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.
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.
NAME] TYPE]
DOMAIN¶Resolve RFC 6763 DNS-SD and
RFC 2782 SRV 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).
EMAIL@DOMAIN…¶Query PGP keys stored as OPENPGPKEY resource records,
see RFC 7929. Specified e-mail addresses
are converted to the corresponding DNS domain name, and any OPENPGPKEY
keys are printed.
FAMILY]
DOMAIN[:PORT]…¶Query TLS public keys stored as TLSA resource
records, see RFC 6698. A query will be
performed for each of the specified names prefixed with the port and family
("_").
The port number may be specified after a colon ("port._family.domain:"), otherwise
443 will be used by default. The family may be specified as the first argument,
otherwise tcp will be used.
LINK…]¶Shows the global and per-link DNS settings currently in effect. If no command is specified, this is the implied default.
Shows general resolver statistics, including information whether DNSSEC is enabled and available, as well as resolution and validation statistics.
Resets the statistics counters shown in statistics to zero. This operation requires root privileges.
Flushes all DNS resource record caches the service maintains locally. This is mostly
equivalent to sending the SIGUSR2 to the systemd-resolved
service.
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.
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).
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.
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.
Show current cache content, per scope. Use --json= to enable JSON
output.
Show detailed server state information, per DNS Server. Use --json=
to enable JSON output.
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)).
-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/resolved.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¶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.
--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.
--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.
--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).
--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 if already available in the local cache.
--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.
--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.
--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.
--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.
--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.
--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.
--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.
--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¶--version¶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.
-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 those command line options.
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.