Provided by: bind9-utils_9.18.28-0ubuntu0.20.04.1_amd64 
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, 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,
/etc/bind/rndc.conf.
-k key-file
This option indicates key-file as the key file instead of the default,
/etc/bind/rndc.key. The key in /etc/bind/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 after
executing the requested command (e.g., ISC_R_SUCCESS, ISC_R_FAILURE, etc.).
-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 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.
The configuration is saved in a file called viewname.nzf (or, if 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 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, 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.
See also rndc addzone and rndc modzone.
dnssec (-status | -rollover -key id [-alg algorithm] [-when time] | -checkds [-key id
[-alg algorithm]] [-when time] published | withdrawn)) zone [class [view]]
This command allows you to interact with the "dnssec-policy" of a given zone.
rndc dnssec -status show the DNSSEC signing state for the specified zone.
rndc dnssec -rollover allows you to schedule key rollover for a specific key
(overriding the original key lifetime).
rndc dnssec -checkds informs named that the DS for a specified zone's key-signing
key 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.
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
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.)
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's process ID
is returned. This allows an external process to determine when named has completed
halting.
See also rndc stop.
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, or that the
auto-dnssec zone option be set to maintain, and also requires the zone to be
configured to allow dynamic DNS. (See "Dynamic Update Policies" in the
Administrator Reference Manual for more details.)
managed-keys (status | refresh | sync | destroy) [class [view]]
This command inspects and controls the "managed-keys" database which handles RFC
5011 DNSSEC trust anchor maintenance. If a view is specified, these commands are
applied to that view; otherwise, they are applied to all views.
• When run with the status keyword, this prints the current status of the
managed-keys database.
• 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.
• 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.
• 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 is restarted or reconfigured, and all existing key
maintenance states are deleted.
Running rndc reconfig or restarting 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.
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.
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, 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.
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 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 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 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 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, or by specifying querylog yes; in the
options section of 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 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.
retransfer 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.
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.
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.
If serving of stale answers is disabled by rndc-serve-stale off, then it remains
disabled even if named is reloaded or reconfigured. rndc serve-stale reset restores
the setting as configured in 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]]
This command prints the configuration of a running zone.
See also rndc zonestatus.
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 command requires that the zone be configured with a dnssec-policy, or that the
auto-dnssec zone option be set to allow or maintain, and also requires the zone to
be configured to allow dynamic DNS. (See "Dynamic Update Policies" in the BIND 9
Administrator Reference Manual for more details.)
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 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's process ID is returned. This allows an external process to
determine when 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.
tsig-delete keyname [view]
This command deletes a given TKEY-negotiated key from the server. This does not
apply to statically configured TSIG keys.
tsig-list
This command lists the names of all TSIG keys currently configured for use by named
in each view. The list includes both statically configured keys and dynamic
TKEY-negotiated keys.
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), rndc-confgen(8), named(8), named.conf(5), BIND 9 Administrator Reference
Manual.
AUTHOR
Internet Systems Consortium
COPYRIGHT
2024, Internet Systems Consortium