Updated: 2021/Dec/3

unbound-control(8)              unbound 1.13.1              unbound-control(8)

       unbound-control, unbound-control-setup - Unbound remote server control

       unbound-control [-hq] [-c cfgfile] [-s server] command

       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.

       There are several commands that the server understands.

       start  Start the server. Simply execs unbound(8).  The unbound
              executable is searched for in the PATH set in the environment.
              It is started with the config file specified using -c or the
              default 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.

              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.

              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
              connection 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

       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
              nonterminal (there is still data in domain names below the
              removed name), NOERROR nodata answers are the result for that

              Add local zones read from stdin of unbound-control. Input is
              read per line, with name space type on a line. For bulk

              Remove local zones read from stdin of unbound-control. Input is
              one name per line. For bulk removals.

              Add local data RRs read from stdin of unbound-control. Input is
              one RR per line. For bulk additions.

              Remove local data RRs read from stdin of unbound-control. Input
              is one name per line. For bulk removals.

              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.

              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.
              Loading 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_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
              implementation of this command (so, with serve-expired enabled,
              it'll serve that information but schedule a prefetch for new

              Remove all bogus data from the cache.

              Remove all negative data from the cache.  This is nxdomain
              answers, 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.

              Reset statistics to zero.

              Drop the queries that are worked on.  Stops working on the
              queries that the server is working on now.  The cache is
              unaffected.  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.

              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

       flush_infra all|IP
              If all then entire infra cache is emptied.  If a specific IP
              address, the entry for that address is removed from the cache.
              It contains EDNS, ping and lameness data.

              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
              values 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

              The values that work are: statistics-interval,
              statistics-cumulative, 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, identity, version, val-log-level,
              val-log-squelch, ignore-cd-flag, add-holddown, del-holddown,
              keep-missing, tcp-upstream, ssl-upstream, max-udp-size,
              ratelimit, ip-ratelimit, cache-max-ttl, cache-min-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 "",
              nothing 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 the stub zones in use.  These are printed one by one to the
              output.  This includes the root hints in use.

              List the forward zones in use.  These are printed zone by zone
              to the output.

              List the zones with domain-insecure.

              List the local zones in use.  These are printed one per line
              with zone type.

              List the local data RRs in use.  The resource records are

       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
              remove 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
              insecurely 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

       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
              nameservers 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
              forward-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
              nameservers 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 the auth zones that are configured.  Printed one per line
              with a status, indicating if the zone is expired and current
              serial 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
              sequence 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

       view_local_datas view
              Add a list of local_data for given view from stdin.  Like

       The unbound-control program exits with status code 1 on error, 0 on

       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
       configured 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

       The stats command shows a number of statistic counters.

              number of queries received by thread

              number of queries rate limited by thread

              number of queries that were successfully answered using a cache

              number of queries that needed recursive processing

              number of queries that were encrypted and successfully
              decapsulated by dnscrypt.

              number of queries that were requesting dnscrypt certificates.

              number of queries received on dnscrypt port that were cleartext
              and not a request for certificates.

              number of request that were neither cleartext, not valid
              dnscrypt messages.

              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.

              number of replies that served an expired cache entry.

              The number of replies sent to queries that needed recursive
              processing. Could be smaller than threadX.num.cachemiss if due
              to timeouts no replies were sent for some queries.

              The average number of requests in the internal recursive
              processing request list on insert of a new incoming recursive
              processing query.

              Maximum size attained by the internal recursive processing
              request list.

              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.

              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.

              Current size of the request list, includes internally generated
              queries (such as priming queries and glue lookups).

              Current size of the request list, only the requests from client

              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.

              The median of the time it took to answer queries that needed
              recursive 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
              average can be bigger than the median.  This median has been
              calculated by interpolation from a histogram.

              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.

              summed over threads.

              summed over threads.

              summed over threads.

              summed over threads.

              summed over threads.

              summed over threads.

              summed over threads.

              summed over threads.

              summed over threads.

              summed over threads.

              averaged over threads.

              the maximum of the thread requestlist.max values.

              summed over threads.

              summed over threads.

              summed over threads.

              averaged over threads.

              summed over threads.

              current time in seconds since 1970.

              uptime since server boot in seconds.

              time since last statistics printout, in seconds.

              Memory in bytes in use by the RRset cache.

              Memory in bytes in use by the message cache.

              Memory in bytes in use by the dnscrypt shared secrets cache.

              Memory in bytes in use by the dnscrypt nonce cache.

              Memory in bytes in use by the iterator module.

              Memory in bytes in use by the validator module. Includes the key
              cache and negative cache.

              Memory in bytes in used by the TCP and TLS stream wait buffers.
              These are answers waiting to be written back to the clients.

              Memory in bytes used by the HTTP/2 query buffers. Containing
              (partial) DNS queries waiting for request stream completion.

              Memory in bytes used by the HTTP/2 response buffers. Containing
              DNS responses waiting to be written back to the clients.

              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.

              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
              omitted for brevity.

              Number of queries with query types 256-65535.

              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
              update.  num.query.class.other is printed for classes 256-65535.

              The total number of queries over all threads with query opcode
              QUERY.  Also printed for other opcodes, UPDATE, ...

              Number of queries that were made using TCP towards the unbound

              Number of queries that the unbound server made using TCP
              outgoing towards other servers.

              Number of queries that were made using TLS towards the unbound
              server.  These are also counted in num.query.tcp, because TLS
              uses TCP.

              Number of TLS session resumptions, these are queries over TLS
              towards the unbound server where the client negotiated a TLS
              session resumption key.

              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.

              Number of queries that were made using IPv6 towards the unbound

              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.

              number of queries that had an EDNS OPT record present.

              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.

              The number of queries that are turned away from being send to
              nameserver due to ratelimiting.

              The number of dnscrypt queries that did not find a shared secret
              in the cache.  The can be use to compute the shared secret

              The number of dnscrypt queries that found a nonce hit in the
              nonce cache and hence are considered a query replay.

              The number of answers to queries, from cache or from recursion,
              that had the return code NXDOMAIN. Also printed for the other
              return codes.

              The number of answers to queries that had the pseudo return code
              nodata.  This means the actual return code was NOERROR, but
              additionally, no data was carried in the answer (making what is
              called a NOERROR/NODATA answer).  These queries are also
              included in the num.answer.rcode.NOERROR number.  Common for
              AAAA lookups when an A record exists, and no AAAA.

              Number of answers that were secure.  The answer validated
              correctly.  The AD bit might have been set in some of these
              answers, where the client signalled (with DO or AD bit in the
              query) that they were ready to accept the AD bit in the answer.

              Number of answers that were bogus.  These answers resulted in
              SERVFAIL to the client because the answer failed validation.

              The number of rrsets marked bogus by the validator.  Increased
              for every RRset inspection that fails.

              Number of queries that were refused or dropped because they
              failed the access control settings.

              Replies that were unwanted or unsolicited.  Could have been
              random 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).

              The number of items (DNS replies) in the message cache.

              The number of RRsets in the rrset cache.  This includes rrsets
              used by the messages in the message cache, but also delegation

              The number of items in the infra cache.  These are IP addresses
              with their timing and protocol support information.

              The number of items in the key cache.  These are DNSSEC keys,
              one item per delegation point, and their validation status.

              The number of items in the shared secret cache. These are
              precomputed shared secrets for a given client public key/server
              secret key pair. Shared secrets are CPU intensive and this cache
              allows unbound to avoid recomputing the shared secret when
              multiple dnscrypt queries are sent from the same client.

              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`

              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.

              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.

              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.

              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.

              Number of queries that got an answer that contained EDNS client
              subnet data.

              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.

              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.

              unbound configuration file.

              directory with private keys (unbound_server.key and
              unbound_control.key) and self-signed certificates
              (unbound_server.pem and unbound_control.pem).

       unbound.conf(5), unbound(8).

NLnet Labs                       Feb  9, 2021               unbound-control(8)