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 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.
- 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 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 succeeds.
- 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 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 additions.
- 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. 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_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.
- flush_bogus
- Remove all bogus data from the cache.
- flush_negative
- 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.
- 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 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.
- 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 address, 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 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 initialized.
- 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, 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 "", 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_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 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 unbound.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 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.
- 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_local_data view RR data...
- local_data for given view.
- view_local_data_remove view name
- local_data_remove for given view.
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 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 unbound.conf.
STATISTIC COUNTERS¶
The stats command shows a number of statistic counters.
- threadX.num.queries
- number of queries received 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.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.zero_ttl
- number of replies with ttl zero, because they served an expired cache
entry.
- threadX.num.recursivereplies
- 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.
- threadX.requestlist.avg
- The average number of requests in the internal recursive processing
request list on insert of a new incoming recursive processing query.
- threadX.requestlist.max
- Maximum size attained by the internal recursive processing request
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 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.
- 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.prefetch
- summed over threads.
- total.num.zero_ttl
- 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.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.
- 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 omitted 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 update.
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 outgoing towards
other servers.
- 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.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 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.
- num.answer.secure
- 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.
- 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 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).
- 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.
FILES¶
- /etc/unbound/unbound.conf
- unbound configuration file.
- /etc/unbound
- directory with private keys (unbound_server.key and unbound_control.key)
and self-signed certificates (unbound_server.pem and
unbound_control.pem).