|
NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXAMPLES | SEE ALSO | NOTES | COLOPHON |
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[1] and DNS-SD[2]
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[3] 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[4] 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 validations.
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.
-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[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
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
Enables service resolution. This enables DNS-SD and simple SRV
service resolution, depending on the specified list of parameters
(see above).
--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.
--openpgp
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.
--tlsa
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.
--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.
--statistics
If specified general resolver statistics are shown, 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.
--flush-caches
Flushes all DNS resource record caches the service maintains
locally.
--status
Shows the global and per-link DNS settings in currently in
effect.
-h, --help
Print a short help text and exit.
--version
Print a short version string and exit.
--no-pager
Do not pipe output into a pager.
Example 1. Retrieve the addresses of the "www.0pointer.net" domain
$ systemd-resolve 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
$ systemd-resolve 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
$ 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]
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
$ systemd-resolve --openpgp zbyszek@fedoraproject.org
d08ee310438ca124a6149ea5cc21b6313b390dce485576eff96f8722._openpgpkey.fedoraproject.org. IN OPENPGPKEY
mQINBFBHPMsBEACeInGYJCb+7TurKfb6wGyTottCDtiSJB310i37/6ZYoeIay/5soJjlMyf
MFQ9T2XNT/0LM6gTa0MpC1st9LnzYTMsT6tzRly1D1UbVI6xw0g0vE5y2Cjk3xUwAynCsSs
...
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)
1. SRV
https://tools.ietf.org/html/rfc2782
2. DNS-SD
https://tools.ietf.org/html/rfc6763
3. OPENPGPKEY
https://tools.ietf.org/html/rfc7929
4. TLSA
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
This page is part of the systemd (systemd system and service manager)
project. Information about the project can be found at
⟨http://www.freedesktop.org/wiki/Software/systemd⟩. If you have a bug
report for this manual page, see
⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩. This
page was obtained from the project's upstream Git repository
⟨https://github.com/systemd/systemd.git⟩ on 2017-07-05. If you dis‐
cover any rendering problems in this HTML version of the page, or you
believe there is a better or more up-to-date source for the page, or
you have corrections or improvements to the information in this
COLOPHON (which is not part of the original manual page), send a mail
to man-pages@man7.org
systemd 234 SYSTEMD-RESOLVE(1)
Pages that refer to this page: systemd.directives(7), systemd.index(7), systemd-resolved.service(8)