unbound-control(8) unbound 1.13.1 unbound-control(8)
NAME
unbound-control, unbound-control-setup - Unbound remote server control
utility.
SYNOPSIS
unbound-control [-hq] [-c cfgfile] [-s server] command
DESCRIPTION
Unbound-control performs remote administration on the unbound(8) DNS
server. It reads the configuration file, contacts the unbound server
over SSL sends the command and displays the result.
The available options are:
-h Show the version and commandline option help.
-c cfgfile
The config file to read with settings. If not given the default
config file /etc/unbound/unbound.conf is used.
-s server[@port]
IPv4 or IPv6 address of the server to contact. If not given,
the address is read from the config file.
-q quiet, if the option is given it does not print anything if it
works ok.
COMMANDS
There are several commands that the server understands.
start Start the server. Simply execs unbound(8). The unbound exe-
cutable is searched for in the PATH set in the environment. It
is started with the config file specified using -c or the de-
fault config file.
stop Stop the server. The server daemon exits.
reload Reload the server. This flushes the cache and reads the config
file fresh.
verbosity number
Change verbosity value for logging. Same values as verbosity
keyword in unbound.conf(5). This new setting lasts until the
server is issued a reload (taken from config file again), or the
next verbosity control command.
log_reopen
Reopen the logfile, close and open it. Useful for logrotation
to make the daemon release the file it is logging to. If you
are using syslog it will attempt to close and open the syslog
(which may not work if chrooted).
stats Print statistics. Resets the internal counters to zero, this can
be controlled using the statistics-cumulative config statement.
Statistics are printed with one [name]: [value] per line.
stats_noreset
Peek at statistics. Prints them like the stats command does, but
does not reset the internal counters to zero.
status Display server status. Exit code 3 if not running (the connec-
tion to the port is refused), 1 on error, 0 if running.
local_zone name type
Add new local zone with name and type. Like local-zone config
statement. If the zone already exists, the type is changed to
the given argument.
local_zone_remove name
Remove the local zone with the given name. Removes all local
data inside it. If the zone does not exist, the command suc-
ceeds.
local_data RR data...
Add new local data, the given resource record. Like local-data
config statement, except for when no covering zone exists. In
that case this remote control command creates a transparent zone
with the same name as this record. This command is not good at
returning detailed syntax errors.
local_data_remove name
Remove all RR data from local name. If the name already has no
items, nothing happens. Often results in NXDOMAIN for the name
(in a static zone), but if the name has become an empty nonter-
minal (there is still data in domain names below the removed
name), NOERROR nodata answers are the result for that name.
local_zones
Add local zones read from stdin of unbound-control. Input is
read per line, with name space type on a line. For bulk addi-
tions.
local_zones_remove
Remove local zones read from stdin of unbound-control. Input is
one name per line. For bulk removals.
local_datas
Add local data RRs read from stdin of unbound-control. Input is
one RR per line. For bulk additions.
local_datas_remove
Remove local data RRs read from stdin of unbound-control. Input
is one name per line. For bulk removals.
dump_cache
The contents of the cache is printed in a text format to stdout.
You can redirect it to a file to store the cache in a file.
load_cache
The contents of the cache is loaded from stdin. Uses the same
format as dump_cache uses. Loading the cache with old, or wrong
data can result in old or wrong data returned to clients. Load-
ing data into the cache in this way is supported in order to aid
with debugging.
lookup name
Print to stdout the name servers that would be used to look up
the name specified.
flush name
Remove the name from the cache. Removes the types A, AAAA, NS,
SOA, CNAME, DNAME, MX, PTR, SRV and NAPTR. Because that is fast
to do. Other record types can be removed using flush_type or
flush_zone.
flush_type name type
Remove the name, type information from the cache.
flush_zone name
Remove all information at or below the name from the cache. The
rrsets and key entries are removed so that new lookups will be
performed. This needs to walk and inspect the entire cache, and
is a slow operation. The entries are set to expired in the im-
plementation of this command (so, with serve-expired enabled,
it'll serve that information but schedule a prefetch for new in-
formation).
flush_bogus
Remove all bogus data from the cache.
flush_negative
Remove all negative data from the cache. This is nxdomain an-
swers, nodata answers and servfail answers. Also removes bad
key entries (which could be due to failed lookups) from the
dnssec key cache, and iterator last-resort lookup failures from
the rrset cache.
flush_stats
Reset statistics to zero.
flush_requestlist
Drop the queries that are worked on. Stops working on the
queries that the server is working on now. The cache is unaf-
fected. No reply is sent for those queries, probably making
those users request again later. Useful to make the server
restart working on queries with new settings, such as a higher
verbosity level.
dump_requestlist
Show what is worked on. Prints all queries that the server is
currently working on. Prints the time that users have been
waiting. For internal requests, no time is printed. And then
prints out the module status. This prints the queries from the
first thread, and not queries that are being serviced from other
threads.
flush_infra all|IP
If all then entire infra cache is emptied. If a specific IP ad-
dress, the entry for that address is removed from the cache. It
contains EDNS, ping and lameness data.
dump_infra
Show the contents of the infra cache.
set_option opt: val
Set the option to the given value without a reload. The cache
is therefore not flushed. The option must end with a ':' and
whitespace must be between the option and the value. Some val-
ues may not have an effect if set this way, the new values are
not written to the config file, not all options are supported.
This is different from the set_option call in libunbound, where
all values work because unbound has not been initialized.
The values that work are: statistics-interval, statistics-cumu-
lative, do-not-query-localhost, harden-short-bufsize,
harden-large-queries, harden-glue, harden-dnssec-stripped,
harden-below-nxdomain, harden-referral-path, prefetch,
prefetch-key, log-queries, hide-identity, hide-version, iden-
tity, version, val-log-level, val-log-squelch, ignore-cd-flag,
add-holddown, del-holddown, keep-missing, tcp-upstream, ssl-up-
stream, max-udp-size, ratelimit, ip-ratelimit, cache-max-ttl,
cache-min-ttl, cache-max-negative-ttl.
get_option opt
Get the value of the option. Give the option name without a
trailing ':'. The value is printed. If the value is "", noth-
ing is printed and the connection closes. On error 'error ...'
is printed (it gives a syntax error on unknown option). For
some options a list of values, one on each line, is printed.
The options are shown from the config file as modified with
set_option. For some options an override may have been taken
that does not show up with this command, not results from e.g.
the verbosity and forward control commands. Not all options
work, see list_stubs, list_forwards, list_local_zones and
list_local_data for those.
list_stubs
List the stub zones in use. These are printed one by one to the
output. This includes the root hints in use.
list_forwards
List the forward zones in use. These are printed zone by zone
to the output.
list_insecure
List the zones with domain-insecure.
list_local_zones
List the local zones in use. These are printed one per line
with zone type.
list_local_data
List the local data RRs in use. The resource records are
printed.
insecure_add zone
Add a domain-insecure for the given zone, like the statement in
unbound.conf. Adds to the running unbound without affecting the
cache contents (which may still be bogus, use flush_zone to re-
move it), does not affect the config file.
insecure_remove zone
Removes domain-insecure for the given zone.
forward_add [+i] zone addr ...
Add a new forward zone to running unbound. With +i option also
adds a domain-insecure for the zone (so it can resolve inse-
curely if you have a DNSSEC root trust anchor configured for
other names). The addr can be IP4, IP6 or nameserver names,
like forward-zone config in unbound.conf.
forward_remove [+i] zone
Remove a forward zone from running unbound. The +i also removes
a domain-insecure for the zone.
stub_add [+ip] zone addr ...
Add a new stub zone to running unbound. With +i option also
adds a domain-insecure for the zone. With +p the stub zone is
set to prime, without it it is set to notprime. The addr can be
IP4, IP6 or nameserver names, like the stub-zone config in un-
bound.conf.
stub_remove [+i] zone
Remove a stub zone from running unbound. The +i also removes a
domain-insecure for the zone.
forward [off | addr ... ]
Setup forwarding mode. Configures if the server should ask
other upstream nameservers, should go to the internet root name-
servers itself, or show the current config. You could pass the
nameservers after a DHCP update.
Without arguments the current list of addresses used to forward
all queries to is printed. On startup this is from the for-
ward-zone "." configuration. Afterwards it shows the status.
It prints off when no forwarding is used.
If off is passed, forwarding is disabled and the root name-
servers are used. This can be used to avoid to avoid buggy or
non-DNSSEC supporting nameservers returned from DHCP. But may
not work in hotels or hotspots.
If one or more IPv4 or IPv6 addresses are given, those are then
used to forward queries to. The addresses must be separated
with spaces. With '@port' the port number can be set explicitly
(default port is 53 (DNS)).
By default the forwarder information from the config file for
the root "." is used. The config file is not changed, so after
a reload these changes are gone. Other forward zones from the
config file are not affected by this command.
ratelimit_list [+a]
List the domains that are ratelimited. Printed one per line
with current estimated qps and qps limit from config. With +a
it prints all domains, not just the ratelimited domains, with
their estimated qps. The ratelimited domains return an error
for uncached (new) queries, but cached queries work as normal.
ip_ratelimit_list [+a]
List the ip addresses that are ratelimited. Printed one per
line with current estimated qps and qps limit from config. With
+a it prints all ips, not just the ratelimited ips, with their
estimated qps. The ratelimited ips are dropped before checking
the cache.
list_auth_zones
List the auth zones that are configured. Printed one per line
with a status, indicating if the zone is expired and current se-
rial number.
auth_zone_reload zone
Reload the auth zone from zonefile. The zonefile is read in
overwriting the current contents of the zone in memory. This
changes the auth zone contents itself, not the cache contents.
Such cache contents exists if you set unbound to validate with
for-upstream yes and that can be cleared with flush_zone zone.
auth_zone_transfer zone
Transfer the auth zone from master. The auth zone probe se-
quence is started, where the masters are probed to see if they
have an updated zone (with the SOA serial check). And then the
zone is transferred for a newer zone version.
rpz_enable zone
Enable the RPZ zone if it had previously been disabled.
rpz_enable zone
Disable the RPZ zone.
view_list_local_zones view
list_local_zones for given view.
view_local_zone view name type
local_zone for given view.
view_local_zone_remove view name
local_zone_remove for given view.
view_list_local_data view
list_local_data for given view.
view_local_data view RR data...
local_data for given view.
view_local_data_remove view name
local_data_remove for given view.
view_local_datas_remove view
Remove a list of local_data for given view from stdin. Like lo-
cal_datas_remove.
view_local_datas view
Add a list of local_data for given view from stdin. Like lo-
cal_datas.
EXIT CODE
The unbound-control program exits with status code 1 on error, 0 on
success.
SET UP
The setup requires a self-signed certificate and private keys for both
the server and client. The script unbound-control-setup generates
these in the default run directory, or with -d in another directory.
If you change the access control permissions on the key files you can
decide who can use unbound-control, by default owner and group but not
all users. Run the script under the same username as you have config-
ured in unbound.conf or as root, so that the daemon is permitted to
read the files, for example with:
sudo -u unbound unbound-control-setup
If you have not configured a username in unbound.conf, the keys need
read permission for the user credentials under which the daemon is
started. The script preserves private keys present in the directory.
After running the script as root, turn on control-enable in un-
bound.conf.
STATISTIC COUNTERS
The stats command shows a number of statistic counters.
threadX.num.queries
number of queries received by thread
threadX.num.queries_ip_ratelimited
number of queries rate limited by thread
threadX.num.cachehits
number of queries that were successfully answered using a cache
lookup
threadX.num.cachemiss
number of queries that needed recursive processing
threadX.num.dnscrypt.crypted
number of queries that were encrypted and successfully decapsu-
lated by dnscrypt.
threadX.num.dnscrypt.cert
number of queries that were requesting dnscrypt certificates.
threadX.num.dnscrypt.cleartext
number of queries received on dnscrypt port that were cleartext
and not a request for certificates.
threadX.num.dnscrypt.malformed
number of request that were neither cleartext, not valid
dnscrypt messages.
threadX.num.prefetch
number of cache prefetches performed. This number is included
in cachehits, as the original query had the unprefetched answer
from cache, and resulted in recursive processing, taking a slot
in the requestlist. Not part of the recursivereplies (or the
histogram thereof) or cachemiss, as a cache response was sent.
threadX.num.expired
number of replies that served an expired cache entry.
threadX.num.recursivereplies
The number of replies sent to queries that needed recursive pro-
cessing. Could be smaller than threadX.num.cachemiss if due to
timeouts no replies were sent for some queries.
threadX.requestlist.avg
The average number of requests in the internal recursive pro-
cessing request list on insert of a new incoming recursive pro-
cessing query.
threadX.requestlist.max
Maximum size attained by the internal recursive processing re-
quest list.
threadX.requestlist.overwritten
Number of requests in the request list that were overwritten by
newer entries. This happens if there is a flood of queries that
recursive processing and the server has a hard time.
threadX.requestlist.exceeded
Queries that were dropped because the request list was full.
This happens if a flood of queries need recursive processing,
and the server can not keep up.
threadX.requestlist.current.all
Current size of the request list, includes internally generated
queries (such as priming queries and glue lookups).
threadX.requestlist.current.user
Current size of the request list, only the requests from client
queries.
threadX.recursion.time.avg
Average time it took to answer queries that needed recursive
processing. Note that queries that were answered from the cache
are not in this average.
threadX.recursion.time.median
The median of the time it took to answer queries that needed re-
cursive processing. The median means that 50% of the user
queries were answered in less than this time. Because of big
outliers (usually queries to non responsive servers), the aver-
age can be bigger than the median. This median has been calcu-
lated by interpolation from a histogram.
threadX.tcpusage
The currently held tcp buffers for incoming connections. A spot
value on the time of the request. This helps you spot if the
incoming-num-tcp buffers are full.
total.num.queries
summed over threads.
total.num.cachehits
summed over threads.
total.num.cachemiss
summed over threads.
total.num.dnscrypt.crypted
summed over threads.
total.num.dnscrypt.cert
summed over threads.
total.num.dnscrypt.cleartext
summed over threads.
total.num.dnscrypt.malformed
summed over threads.
total.num.prefetch
summed over threads.
total.num.expired
summed over threads.
total.num.recursivereplies
summed over threads.
total.requestlist.avg
averaged over threads.
total.requestlist.max
the maximum of the thread requestlist.max values.
total.requestlist.overwritten
summed over threads.
total.requestlist.exceeded
summed over threads.
total.requestlist.current.all
summed over threads.
total.recursion.time.median
averaged over threads.
total.tcpusage
summed over threads.
time.now
current time in seconds since 1970.
time.up
uptime since server boot in seconds.
time.elapsed
time since last statistics printout, in seconds.
EXTENDED STATISTICS
mem.cache.rrset
Memory in bytes in use by the RRset cache.
mem.cache.message
Memory in bytes in use by the message cache.
mem.cache.dnscrypt_shared_secret
Memory in bytes in use by the dnscrypt shared secrets cache.
mem.cache.dnscrypt_nonce
Memory in bytes in use by the dnscrypt nonce cache.
mem.mod.iterator
Memory in bytes in use by the iterator module.
mem.mod.validator
Memory in bytes in use by the validator module. Includes the key
cache and negative cache.
mem.streamwait
Memory in bytes in used by the TCP and TLS stream wait buffers.
These are answers waiting to be written back to the clients.
mem.http.query_buffer
Memory in bytes used by the HTTP/2 query buffers. Containing
(partial) DNS queries waiting for request stream completion.
mem.http.response_buffer
Memory in bytes used by the HTTP/2 response buffers. Containing
DNS responses waiting to be written back to the clients.
histogram.<sec>.<usec>.to.<sec>.<usec>
Shows a histogram, summed over all threads. Every element counts
the recursive queries whose reply time fit between the lower and
upper bound. Times larger or equal to the lowerbound, and
smaller than the upper bound. There are 40 buckets, with bucket
sizes doubling.
num.query.type.A
The total number of queries over all threads with query type A.
Printed for the other query types as well, but only for the
types for which queries were received, thus =0 entries are omit-
ted for brevity.
num.query.type.other
Number of queries with query types 256-65535.
num.query.class.IN
The total number of queries over all threads with query class IN
(internet). Also printed for other classes (such as CH (CHAOS)
sometimes used for debugging), or NONE, ANY, used by dynamic up-
date. num.query.class.other is printed for classes 256-65535.
num.query.opcode.QUERY
The total number of queries over all threads with query opcode
QUERY. Also printed for other opcodes, UPDATE, ...
num.query.tcp
Number of queries that were made using TCP towards the unbound
server.
num.query.tcpout
Number of queries that the unbound server made using TCP outgo-
ing towards other servers.
num.query.tls
Number of queries that were made using TLS towards the unbound
server. These are also counted in num.query.tcp, because TLS
uses TCP.
num.query.tls.resume
Number of TLS session resumptions, these are queries over TLS
towards the unbound server where the client negotiated a TLS
session resumption key.
num.query.https
Number of queries that were made using HTTPS towards the unbound
server. These are also counted in num.query.tcp and
num.query.tls, because HTTPS uses TLS and TCP.
num.query.ipv6
Number of queries that were made using IPv6 towards the unbound
server.
num.query.flags.RD
The number of queries that had the RD flag set in the header.
Also printed for flags QR, AA, TC, RA, Z, AD, CD. Note that
queries with flags QR, AA or TC may have been rejected because
of that.
num.query.edns.present
number of queries that had an EDNS OPT record present.
num.query.edns.DO
number of queries that had an EDNS OPT record with the DO
(DNSSEC OK) bit set. These queries are also included in the
num.query.edns.present number.
num.query.ratelimited
The number of queries that are turned away from being send to
nameserver due to ratelimiting.
num.query.dnscrypt.shared_secret.cachemiss
The number of dnscrypt queries that did not find a shared secret
in the cache. The can be use to compute the shared secret hi-
trate.
num.query.dnscrypt.replay
The number of dnscrypt queries that found a nonce hit in the
nonce cache and hence are considered a query replay.
num.answer.rcode.NXDOMAIN
The number of answers to queries, from cache or from recursion,
that had the return code NXDOMAIN. Also printed for the other
return codes.
num.answer.rcode.nodata
The number of answers to queries that had the pseudo return code
nodata. This means the actual return code was NOERROR, but ad-
ditionally, no data was carried in the answer (making what is
called a NOERROR/NODATA answer). These queries are also in-
cluded in the num.answer.rcode.NOERROR number. Common for AAAA
lookups when an A record exists, and no AAAA.
num.answer.secure
Number of answers that were secure. The answer validated cor-
rectly. The AD bit might have been set in some of these an-
swers, where the client signalled (with DO or AD bit in the
query) that they were ready to accept the AD bit in the answer.
num.answer.bogus
Number of answers that were bogus. These answers resulted in
SERVFAIL to the client because the answer failed validation.
num.rrset.bogus
The number of rrsets marked bogus by the validator. Increased
for every RRset inspection that fails.
unwanted.queries
Number of queries that were refused or dropped because they
failed the access control settings.
unwanted.replies
Replies that were unwanted or unsolicited. Could have been ran-
dom traffic, delayed duplicates, very late answers, or could be
spoofing attempts. Some low level of late answers and delayed
duplicates are to be expected with the UDP protocol. Very high
values could indicate a threat (spoofing).
msg.cache.count
The number of items (DNS replies) in the message cache.
rrset.cache.count
The number of RRsets in the rrset cache. This includes rrsets
used by the messages in the message cache, but also delegation
information.
infra.cache.count
The number of items in the infra cache. These are IP addresses
with their timing and protocol support information.
key.cache.count
The number of items in the key cache. These are DNSSEC keys,
one item per delegation point, and their validation status.
dnscrypt_shared_secret.cache.count
The number of items in the shared secret cache. These are pre-
computed shared secrets for a given client public key/server se-
cret key pair. Shared secrets are CPU intensive and this cache
allows unbound to avoid recomputing the shared secret when mul-
tiple dnscrypt queries are sent from the same client.
dnscrypt_nonce.cache.count
The number of items in the client nonce cache. This cache is
used to prevent dnscrypt queries replay. The client nonce must
be unique for each client public key/server secret key pair.
This cache should be able to host QPS * `replay window` interval
keys to prevent replay of a query during `replay window` sec-
onds.
num.query.authzone.up
The number of queries answered from auth-zone data, upstream
queries. These queries would otherwise have been sent (with
fallback enabled) to the internet, but are now answered from the
auth zone.
num.query.authzone.down
The number of queries for downstream answered from auth-zone
data. These queries are from downstream clients, and have had
an answer from the data in the auth zone.
num.query.aggressive.NOERROR
The number of queries answered using cached NSEC records with
NODATA RCODE. These queries would otherwise have been sent to
the internet, but are now answered using cached data.
num.query.aggressive.NXDOMAIN
The number of queries answered using cached NSEC records with
NXDOMAIN RCODE. These queries would otherwise have been sent to
the internet, but are now answered using cached data.
num.query.subnet
Number of queries that got an answer that contained EDNS client
subnet data.
num.query.subnet_cache
Number of queries answered from the edns client subnet cache.
These are counted as cachemiss by the main counters, but hit the
client subnet specific cache, after getting processed by the
edns client subnet module.
num.rpz.action.<rpz_action>
Number of queries answered using configured RPZ policy, per RPZ
action type. Possible actions are: nxdomain, nodata, passthru,
drop, local_data, disabled, and cname_override.
FILES
/etc/unbound/unbound.conf
unbound configuration file.
/etc/unbound
directory with private keys (unbound_server.key and unbound_con-
trol.key) and self-signed certificates (unbound_server.pem and
unbound_control.pem).
SEE ALSO
unbound.conf(5), unbound(8).
NLnet Labs Feb 9, 2021 unbound-control(8)
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