rndc(8) BIND 9 rndc(8)
NAME
rndc - name server control utility
SYNOPSIS
rndc [-b source-address] [-c config-file] [-k key-file] [-s server] [-p
port] [-q] [-r] [-V] [-y server_key] [[-4] | [-6]] {command}
DESCRIPTION
rndc controls the operation of a name server. If rndc is invoked with
no command line options or arguments, it prints a short summary of the
supported commands and the available options and their arguments.
rndc communicates with the name server over a TCP connection, sending
commands authenticated with digital signatures. In the current versions
of rndc and named <#std-iscman-named>, the only supported
authentication algorithms are HMAC-MD5 (for compatibility), HMAC-SHA1,
HMAC-SHA224, HMAC-SHA256 (default), HMAC-SHA384, and HMAC-SHA512. They
use a shared secret on each end of the connection, which provides
TSIG-style authentication for the command request and the name server's
response. All commands sent over the channel must be signed by a
server_key known to the server.
rndc reads a configuration file to determine how to contact the name
server and decide what algorithm and key it should use.
OPTIONS
-4 This option indicates use of IPv4 only.
-6 This option indicates use of IPv6 only.
-b source-address
This option indicates source-address as the source address for
the connection to the server. Multiple instances are permitted,
to allow setting of both the IPv4 and IPv6 source addresses.
-c config-file
This option indicates config-file as the configuration file
instead of the default, /opt/local/etc/rndc.conf.
-k key-file
This option indicates key-file as the key file instead of the
default, /opt/local/etc/rndc.key. The key in
/opt/local/etc/rndc.key is used to authenticate commands sent to
the server if the config-file does not exist.
-s server
server is the name or address of the server which matches a
server statement in the configuration file for rndc. If no
server is supplied on the command line, the host named by the
default-server clause in the options statement of the rndc
configuration file is used.
-p port
This option instructs BIND 9 to send commands to TCP port port
instead of its default control channel port, 953.
-q This option sets quiet mode, where message text returned by the
server is not printed unless there is an error.
-r This option instructs rndc to print the result code returned by
named <#std-iscman-named> after executing the requested command
(e.g., ISC_R_SUCCESS, ISC_R_FAILURE, etc.).
-t timeout
This option sets the idle timeout period for rndc to timeout
seconds. The default is 60 seconds, and the maximum settable
value is 86400 seconds (1 day). If set to 0, there is no
timeout.
-V This option enables verbose logging.
-y server_key
This option indicates use of the key server_key from the
configuration file. For control message validation to succeed,
server_key must be known by named <#std-iscman-named> with the
same algorithm and secret string. If no server_key is specified,
rndc first looks for a key clause in the server statement of the
server being used, or if no server statement is present for that
host, then in the default-key clause of the options statement.
Note that the configuration file contains shared secrets which
are used to send authenticated control commands to name servers,
and should therefore not have general read or write access.
COMMANDS
A list of commands supported by rndc can be seen by running rndc
without arguments.
Currently supported commands are:
addzone zone [class [view]] configuration
This command adds a zone while the server is running. This
command requires the allow-new-zones option to be set to yes.
The configuration string specified on the command line is the
zone configuration text that would ordinarily be placed in
named.conf <#std-iscman-named.conf>.
The configuration is saved in a file called viewname.nzf (or, if
named <#std-iscman-named> is compiled with liblmdb, an LMDB
database file called viewname.nzd). viewname is the name of the
view, unless the view name contains characters that are
incompatible with use as a file name, in which case a
cryptographic hash of the view name is used instead. When named
<#std-iscman-named> is restarted, the file is loaded into the
view configuration so that zones that were added can persist
after a restart.
This sample addzone command adds the zone example.com to the
default view:
rndc addzone example.com '{ type primary; file "example.com.db";
};'
(Note the brackets around and semi-colon after the zone
configuration text.)
See also rndc delzone and rndc modzone.
delzone [-clean] zone [class [view]]
This command deletes a zone while the server is running.
If the -clean argument is specified, the zone's master file (and
journal file, if any) are deleted along with the zone. Without
the -clean option, zone files must be deleted manually. (If the
zone is of type secondary or stub, the files needing to be
removed are reported in the output of the rndc delzone command.)
If the zone was originally added via rndc addzone, then it is
removed permanently. However, if it was originally configured in
named.conf <#std-iscman-named.conf>, then that original
configuration remains in place; when the server is restarted or
reconfigured, the zone is recreated. To remove it permanently,
it must also be removed from named.conf <#std-iscman-named
.conf>.
See also rndc addzone and rndc modzone.
dnssec The following commands allow you to interact with the
"dnssec-policy" of a given zone.
-checkds [-key id [-alg algorithm]] [-when time] (published |
withdrawn) zone [class [view]]
This command informs named <#std-iscman-named> that the
DS for a specified zone's key-signing key (KSK) has been
confirmed to be published in, or withdrawn from, the
parent zone. This is required in order to complete a KSK
rollover. The -key id and -alg algorithm arguments can
be used to specify a particular KSK, if necessary; if
there is only one key acting as a KSK for the zone, these
arguments can be omitted. The time of publication or
withdrawal for the DS is set to the current time by
default, but can be overridden to a specific time with
the argument -when time, where time is expressed in
YYYYMMDDHHMMSS notation.
-rollover -key id [-alg algorithm] [-when time] zone [class
[view]]
This command allows you to schedule key rollover for a
specific key (overriding the original key lifetime). The
-key id and -alg algorithm arguments specify which key to
roll. The time to start the rollover can be set with
-when time, where time is expressed in YYYYMMDDHHMMSS. If
not set the rollover will start immediately.
-status [-v] zone [class [view]]
This command shows the DNSSEC signing state for the
specified zone. Adding -v also lists no longer used keys
and shows the key states of the keys.
-step zone [class [view]]
This command sends a signal to an instance of named <#
std-iscman-named> for a zone configured with
dnssec-policy in manual mode, telling it to continue with
the operations that had previously been blocked but
logged. This gives the human operator a chance to review
the log messages, understand what will happen next and
then, using rndc dnssec -step, to inform named <#std-
iscman-named> to proceed to the next stage.
dnstap (-reopen | -roll [number])
This command closes and re-opens DNSTAP output files.
rndc dnstap -reopen allows the output file to be renamed
externally, so that named <#std-iscman-named> can truncate and
re-open it.
rndc dnstap -roll causes the output file to be rolled
automatically, similar to log files. The most recent output file
has ".0" appended to its name; the previous most recent output
file is moved to ".1", and so on. If number is specified, then
the number of backup log files is limited to that number.
dumpdb [-all | -cache | -zones | -adb | -bad | -expired | -fail] [view
...] This command dumps the server's caches (default) and/or zones to
the dump file for the specified views. If no view is specified,
all views are dumped. (See the dump-file option in the BIND 9
Administrator Reference Manual.)
fetchlimit [view]
This command dumps a list of servers that are currently being
rate-limited as a result of fetches-per-server settings, and a
list of domain names that are currently being rate-limited as a
result of fetches-per-zone settings.
flush This command flushes the server's cache.
flushname name [view]
This command flushes the given name from the view's DNS cache
and, if applicable, from the view's nameserver address database,
bad server cache, and SERVFAIL cache.
flushtree name [view]
This command flushes the given name, and all of its subdomains,
from the view's DNS cache, address database, bad server cache,
and SERVFAIL cache.
freeze [zone [class [view]]]
This command suspends updates to a dynamic zone. If no zone is
specified, then all zones are suspended. This allows manual
edits to be made to a zone normally updated by dynamic update,
and causes changes in the journal file to be synced into the
master file. All dynamic update attempts are refused while the
zone is frozen.
See also rndc thaw.
halt [-p]
This command stops the server immediately. Recent changes made
through dynamic update or IXFR are not saved to the master
files, but are rolled forward from the journal files when the
server is restarted. If -p is specified, named <#std-iscman-
named>'s process ID is returned. This allows an external process
to determine when named <#std-iscman-named> has completed
halting.
See also rndc stop.
skr -import file zone [class [view]]
This command allows you to import a SKR file for the specified
zone, to support offline KSK signing.
loadkeys [zone [class [view]]]
This command fetches all DNSSEC keys for the given zone from the
key directory. If they are within their publication period, they
are merged into the zone's DNSKEY RRset. Unlike rndc sign,
however, the zone is not immediately re-signed by the new keys,
but is allowed to incrementally re-sign over time.
This command requires that the zone be configured with a
dnssec-policy.
managed-keys (status | refresh | sync | destroy) [class [view]]
This command inspects and controls the "managed-keys" database
which handles RFC 5011 <https://datatracker.ietf.org/doc/html/
rfc5011.html> DNSSEC trust anchor maintenance. If a view is
specified, these commands are applied to that view; otherwise,
they are applied to all views.
o When run with the status keyword, this prints the current
status of the managed-keys database.
o When run with the refresh keyword, this forces an immediate
refresh query to be sent for all the managed keys, updating
the managed-keys database if any new keys are found, without
waiting the normal refresh interval.
o When run with the sync keyword, this forces an immediate dump
of the managed-keys database to disk (in the file
managed-keys.bind or (viewname.mkeys). This synchronizes the
database with its journal file, so that the database's current
contents can be inspected visually.
o When run with the destroy keyword, the managed-keys database
is shut down and deleted, and all key maintenance is
terminated. This command should be used only with extreme
caution.
Existing keys that are already trusted are not deleted from
memory; DNSSEC validation can continue after this command is
used. However, key maintenance operations cease until named
<#std-iscman-named> is restarted or reconfigured, and all
existing key maintenance states are deleted.
Running rndc reconfig or restarting named <#std-iscman-named>
immediately after this command causes key maintenance to be
reinitialized from scratch, just as if the server were being
started for the first time. This is primarily intended for
testing, but it may also be used, for example, to jumpstart
the acquisition of new keys in the event of a trust anchor
rollover, or as a brute-force repair for key maintenance
problems.
memprof [(on | off | dump)]
This command controls memory profiling. To have any effect,
named <#std-iscman-named> must be built with jemalloc, the
library have profiling support enabled and run with the
prof:true allocator configuration. (either via MALLOC_CONF or
/etc/malloc.conf)
The prof_active:false option is recommended to ensure the
profiling overhead does not affect named <#std-iscman-named>
when not needed.
The on and off options will start and stop the jemalloc memory
profiling respectively. When run with the dump option, named <#
std-iscman-named> will dump the profile to the working
directory. The name will be chosen automatically by jemalloc.
modzone zone [class [view]] configuration
This command modifies the configuration of a zone while the
server is running. This command requires the allow-new-zones
option to be set to yes. As with addzone, the configuration
string specified on the command line is the zone configuration
text that would ordinarily be placed in named.conf <#std-iscman-
named.conf>.
If the zone was originally added via rndc addzone, the
configuration changes are recorded permanently and are still in
effect after the server is restarted or reconfigured. However,
if it was originally configured in named.conf <#std-iscman-named
.conf>, then that original configuration remains in place; when
the server is restarted or reconfigured, the zone reverts to its
original configuration. To make the changes permanent, it must
also be modified in named.conf <#std-iscman-named.conf>.
See also rndc addzone and rndc delzone.
notify zone [class [view]]
This command resends NOTIFY messages for the zone.
notrace
This command sets the server's debugging level to 0.
See also rndc trace.
nta [(-class class | -dump | -force | -remove | -lifetime duration)]
domain [view]
This command sets a DNSSEC negative trust anchor (NTA) for
domain, with a lifetime of duration. The default lifetime is
configured in named.conf <#std-iscman-named.conf> via the
nta-lifetime option, and defaults to one hour. The lifetime
cannot exceed one week.
A negative trust anchor selectively disables DNSSEC validation
for zones that are known to be failing because of
misconfiguration rather than an attack. When data to be
validated is at or below an active NTA (and above any other
configured trust anchors), named <#std-iscman-named> aborts the
DNSSEC validation process and treats the data as insecure rather
than bogus. This continues until the NTA's lifetime has elapsed.
NTAs persist across restarts of the named <#std-iscman-named>
server. The NTAs for a view are saved in a file called name.nta,
where name is the name of the view; if it contains characters
that are incompatible with use as a file name, a cryptographic
hash is generated from the name of the view.
An existing NTA can be removed by using the -remove option.
An NTA's lifetime can be specified with the -lifetime option.
TTL-style suffixes can be used to specify the lifetime in
seconds, minutes, or hours. If the specified NTA already exists,
its lifetime is updated to the new value. Setting lifetime to
zero is equivalent to -remove.
If -dump is used, any other arguments are ignored and a list of
existing NTAs is printed. Note that this may include NTAs that
are expired but have not yet been cleaned up.
Normally, named <#std-iscman-named> periodically tests to see
whether data below an NTA can now be validated (see the
nta-recheck option in the Administrator Reference Manual for
details). If data can be validated, then the NTA is regarded as
no longer necessary and is allowed to expire early. The -force
parameter overrides this behavior and forces an NTA to persist
for its entire lifetime, regardless of whether data could be
validated if the NTA were not present.
The view class can be specified with -class. The default is
class IN, which is the only class for which DNSSEC is currently
supported.
All of these options can be shortened, i.e., to -l, -r, -d, -f,
and -c.
Unrecognized options are treated as errors. To refer to a domain
or view name that begins with a hyphen, use a double-hyphen (--)
on the command line to indicate the end of options.
querylog [(on | off)]
This command enables or disables query logging. For backward
compatibility, this command can also be used without an argument
to toggle query logging on and off.
Query logging can also be enabled by explicitly directing the
queries category to a channel in the logging section of
named.conf <#std-iscman-named.conf>, or by specifying querylog
yes; in the options section of named.conf <#std-iscman-named
.conf>.
reconfig
This command reloads the configuration file and loads new zones,
but does not reload existing zone files even if they have
changed. This is faster than a full rndc reload when there is a
large number of zones, because it avoids the need to examine the
modification times of the zone files.
recursing
This command dumps the list of queries named <#std-iscman-named>
is currently recursing on, and the list of domains to which
iterative queries are currently being sent.
The first list includes all unique clients that are waiting for
recursion to complete, including the query that is awaiting a
response and the timestamp (seconds since the Unix epoch) of
when named started processing this client query.
The second list comprises of domains for which there are active
(or recently active) fetches in progress. It reports the number
of active fetches for each domain and the number of queries that
have been passed (allowed) or dropped (spilled) as a result of
the fetches-per-zone limit. (Note: these counters are not
cumulative over time; whenever the number of active fetches for
a domain drops to zero, the counter for that domain is deleted,
and the next time a fetch is sent to that domain, it is
recreated with the counters set to zero).
refresh zone [class [view]]
This command schedules zone maintenance for the given zone.
reload This command reloads the configuration file and zones.
zone [class [view]]
If a zone is specified, this command reloads only the given
zone. If no zone is specified, the reloading happens
asynchronously.
reset-stats <counter-name ...>
This command resets the requested statistics counters.
At least one counter name must be provided. Currently the
following counters are supported: recursive-high-water,
tcp-high-water.
responselog [on | off]
This command enables or disables response logging. For backward
compatibility, this command can also be used without an argument
to toggle response logging on and off.
Unlike query logging, response logging cannot be enabled by
explicitly directing the responses category to a channel in the
logging section of named.conf <#std-iscman-named.conf>, but it
can still be enabled by specifying responselog yes; in the
options section of named.conf <#std-iscman-named.conf>.
retransfer [-force] zone [class [view]]
This command retransfers the given secondary zone from the
primary server.
If the zone is configured to use inline-signing, the signed
version of the zone is discarded; after the retransfer of the
unsigned version is complete, the signed version is regenerated
with new signatures. With the optional -force argument provided
if there is an ongoing zone transfer it will be aborted before a
new zone transfer is scheduled.
scan This command scans the list of available network interfaces for
changes, without performing a full rndc reconfig or waiting for
the interface-interval timer.
secroots [-] [view ...]
This command dumps the security roots (i.e., trust anchors
configured via trust-anchors, or the managed-keys or
trusted-keys statements [both deprecated], or dnssec-validation
auto) and negative trust anchors for the specified views. If no
view is specified, all views are dumped. Security roots indicate
whether they are configured as trusted keys, managed keys, or
initializing managed keys (managed keys that have not yet been
updated by a successful key refresh query).
If the first argument is -, then the output is returned via the
rndc response channel and printed to the standard output.
Otherwise, it is written to the secroots dump file, which
defaults to named.secroots, but can be overridden via the
secroots-file option in named.conf <#std-iscman-named.conf>.
See also rndc managed-keys.
serve-stale (on | off | reset | status) [class [view]]
This command enables, disables, resets, or reports the current
status of the serving of stale answers as configured in
named.conf <#std-iscman-named.conf>.
If serving of stale answers is disabled by rndc-serve-stale off,
then it remains disabled even if named <#std-iscman-named> is
reloaded or reconfigured. rndc serve-stale reset restores the
setting as configured in named.conf <#std-iscman-named.conf>.
rndc serve-stale status reports whether caching and serving of
stale answers is currently enabled or disabled. It also reports
the values of stale-answer-ttl and max-stale-ttl.
showzone zone [class [view]]
If the server is configured with allow-new-zones set to yes,
then this command prints the configuration of a running zone.
See also rndc addzone, rndc modzone. and rndc delzone.
sign zone [class [view]]
This command fetches all DNSSEC keys for the given zone from the
key directory (see the key-directory option in the BIND 9
Administrator Reference Manual). If they are within their
publication period, they are merged into the zone's DNSKEY
RRset. If the DNSKEY RRset is changed, then the zone is
automatically re-signed with the new key set. This will replace
signatures of inactive keys with signatures from active keys,
and update signatures that expire within the refresh interval.
This command requires that the zone be configured with a
dnssec-policy.
See also rndc loadkeys.
signing [(-list | -clear keyid/algorithm | -clear all | -nsec3param
(parameters | none) | -serial value) zone [class [view]]
This command lists, edits, or removes the DNSSEC signing-state
records for the specified zone. The status of ongoing DNSSEC
operations, such as signing or generating NSEC3 chains, is
stored in the zone in the form of DNS resource records of type
sig-signing-type. rndc signing -list converts these records
into a human-readable form, indicating which keys are currently
signing or have finished signing the zone, and which NSEC3
chains are being created or removed.
rndc signing -clear can remove a single key (specified in the
same format that rndc signing -list uses to display it), or all
keys. In either case, only completed keys are removed; any
record indicating that a key has not yet finished signing the
zone is retained.
rndc signing -nsec3param sets the NSEC3 parameters for a zone.
This is the only supported mechanism for using NSEC3 with
inline-signing zones. Parameters are specified in the same
format as an NSEC3PARAM resource record: hash algorithm, flags,
iterations, and salt, in that order.
Currently, the only defined value for hash algorithm is 1,
representing SHA-1. The flags may be set to 0 or 1, depending on
whether the opt-out bit in the NSEC3 chain should be set.
iterations defines the number of additional times to apply the
algorithm when generating an NSEC3 hash. The salt is a string of
data expressed in hexadecimal, a hyphen (-) if no salt is to be
used, or the keyword auto, which causes named <#std-iscman-
named> to generate a random 64-bit salt.
The only recommended configuration is rndc signing -nsec3param 1
0 0 - zone, i.e. no salt, no additional iterations, no opt-out.
Warning:
Do not use extra iterations, salt, or opt-out unless all
their implications are fully understood. A higher number of
iterations causes interoperability problems and opens servers
to CPU-exhausting DoS attacks.
rndc signing -nsec3param none removes an existing NSEC3 chain
and replaces it with NSEC.
rndc signing -serial value sets the serial number of the zone to
value. If the value would cause the serial number to go
backwards, it is rejected. The primary use of this parameter is
to set the serial number on inline signed zones.
stats This command writes server statistics to the statistics file.
(See the statistics-file option in the BIND 9 Administrator
Reference Manual.)
status This command displays the status of the server. Note that the
number of zones includes the internal bind/CH zone and the
default ./IN hint zone, if there is no explicit root zone
configured.
stop -p
This command stops the server, making sure any recent changes
made through dynamic update or IXFR are first saved to the
master files of the updated zones. If -p is specified, named <#
std-iscman-named>'s process ID is returned. This allows an
external process to determine when named <#std-iscman-named> has
completed stopping.
See also rndc halt.
sync -clean [zone [class [view]]]
This command syncs changes in the journal file for a dynamic
zone to the master file. If the "-clean" option is specified,
the journal file is also removed. If no zone is specified, then
all zones are synced.
tcp-timeouts [initial idle keepalive advertised]
When called without arguments, this command displays the current
values of the tcp-initial-timeout, tcp-idle-timeout,
tcp-keepalive-timeout, and tcp-advertised-timeout options. When
called with arguments, these values are updated. This allows an
administrator to make rapid adjustments when under a
denial-of-service (DoS) attack. See the descriptions of these
options in the BIND 9 Administrator Reference Manual for details
of their use.
thaw [zone [class [view]]]
This command enables updates to a frozen dynamic zone. If no
zone is specified, then all frozen zones are enabled. This
causes the server to reload the zone from disk, and re-enables
dynamic updates after the load has completed. After a zone is
thawed, dynamic updates are no longer refused. If the zone has
changed and the ixfr-from-differences option is in use, the
journal file is updated to reflect changes in the zone.
Otherwise, if the zone has changed, any existing journal file is
removed. If no zone is specified, the reloading happens
asynchronously.
See also rndc freeze.
trace [level]
If no level is specified, this command increments the server's
debugging level by one.
level If specified, this command sets the server's debugging
level to the provided value.
See also rndc notrace.
validation (on | off | status) [view ...]
This command enables, disables, or checks the current status of
DNSSEC validation. By default, validation is enabled.
The cache is flushed when validation is turned on or off to
avoid using data that might differ between states.
zonestatus zone [class [view]]
This command displays the current status of the given zone,
including the master file name and any include files from which
it was loaded, when it was most recently loaded, the current
serial number, the number of nodes, whether the zone supports
dynamic updates, whether the zone is DNSSEC signed, whether it
uses automatic DNSSEC key management or inline signing, and the
scheduled refresh or expiry times for the zone.
See also rndc showzone.
rndc commands that specify zone names, such as reload retransfer, or
zonestatus, can be ambiguous when applied to zones of type redirect.
Redirect zones are always called ., and can be confused with zones of
type hint or with secondary copies of the root zone. To specify a
redirect zone, use the special zone name -redirect, without a trailing
period. (With a trailing period, this would specify a zone called
"-redirect".)
LIMITATIONS
There is currently no way to provide the shared secret for a server_key
without using the configuration file.
Several error messages could be clearer.
SEE ALSO
rndc.conf(5) <#std-iscman-rndc.conf>, rndc-confgen(8) <#std-iscman-
rndc-confgen>, named(8) <#std-iscman-named>, named.conf(5) <#std-
iscman-named.conf>, BIND 9 Administrator Reference Manual.
Author
Internet Systems Consortium
Copyright
2026, Internet Systems Consortium
9.20.21 2026-03-13 rndc(8)
bind 9.20.21 - Generated Fri Apr 3 15:01:47 CDT 2026