NAME
resolvectl, resolvconf - Resolve domain names, IPV4 and IPv6 addresses, DNS resource records, and services; introspect and reconfigure the DNS resolverSYNOPSIS
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.
service [[NAME] TYPE] DOMAIN
Resolve DNS-SD[1] and 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).
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.
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.
status [LINK...]
Shows the global and per-link DNS settings
currently in effect. If no command is specified, this is the implied
default.
statistics
Shows general resolver statistics, 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. This operation requires root privileges.
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.
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).
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.
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.
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)).
OPTIONS
-4, -6By 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[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
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" and
"_outbound", 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.
--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
Short for --json=auto
--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)">COMPATIBILITY_WITH_RESOLVCONF(8)">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: -aRegisters 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.
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
$ 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
$ 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
$ 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 ...
$ resolvectl openpgp [email protected] d08ee310438ca124a6149ea5cc21b6313b390dce485576eff96f8722._openpgpkey.fedoraproject.org. IN OPENPGPKEY mQINBFBHPMsBEACeInGYJCb+7TurKfb6wGyTottCDtiSJB310i37/6ZYoeIay/5soJjlMyf MFQ9T2XNT/0LM6gTa0MpC1st9LnzYTMsT6tzRly1D1UbVI6xw0g0vE5y2Cjk3xUwAynCsSs ...
$ 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
SEE ALSO
systemd(1), systemd-resolved.service(8), systemd.dnssd(5), systemd-networkd.service(8), resolvconf(8)NOTES
- 1.
- DNS-SD
- 2.
- SRV
- 3.
- RFC 7929
- 4.
- RFC 6698
- 5.
- Link-Local Multicast Name Resolution
- 6.
- Multicast DNS
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