systemd Developer Lennart Poettering lennart@poettering.net resolvectl 1 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.service8 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. -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), 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. --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. --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. query HOSTNAME|ADDRESS… Resolve domain names, IPv4 and IPv6 addresses. service [[NAME] TYPE] DOMAIN Resolve DNS-SD and 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 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). openpgp EMAIL@DOMAIN… Query PGP keys stored as OPENPGPKEY resource records. 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. 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 in 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…]] 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 that aren't managed by systemd-networkd.service8. (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 commands may be used to inform systemd-resolved about per-interface DNS configuration determined through external means. The dns command expects IPv4 or IPv6 address specifications of DNS servers to use. The domain command expects valid DNS domains, possibly prefixed with ~, and configures a per-interface search or route-only domain. 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. For details about these settings, their possible values and their effect, see the corresponding options in systemd.network5. 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, 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. 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 resolvconf8 compatibility mode. It accepts mostly the same arguments and pushes all data into systemd-resolved.service8, 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. Note that 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.conf5 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 resolvconf8 for details on this command line options. $ 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 zbyszek@fedoraproject.org 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 systemd1, systemd-resolved.service8, systemd.dnssd5, systemd-networkd.service8, resolvconf8