.. Copyright (C) Internet Systems Consortium, Inc. ("ISC")
..
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..
.. This Source Code Form is subject to the terms of the Mozilla Public
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.. highlight: console
.. _man_rndc:
rndc - name server control utility
----------------------------------
Synopsis
~~~~~~~~
:program:`rndc` [**-b** source-address] [**-c** config-file] [**-k** key-file] [**-s** server] [**-p** port] [**-q**] [**-r**] [**-V**] [**-y** key_id] [[**-4**] | [**-6**]] {command}
Description
~~~~~~~~~~~
``rndc`` controls the operation of a name server; it supersedes the
``ndc`` utility. 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 key_id 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/rndc.conf``.
``-k key-file``
This option indicates ``key-file`` as the key file instead of the default,
``/etc/rndc.key``. The key in ``/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``
after executing the requested command (e.g., ISC_R_SUCCESS,
ISC_R_FAILURE, etc.).
``-V``
This option enables verbose logging.
``-y key_id``
This option indicates use of the key ``key_id`` from the configuration file. For control message validation to succeed, ``key_id`` must be known
by ``named`` with the same algorithm and secret string. If no ``key_id`` 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 master; 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 :iscman:`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 ``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.
``reload`` *zone* [*class* [*view*]]
This command reloads the given zone.
``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 ``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 serving of stale
answers is currently enabled, disabled by the configuration, or
disabled by ``rndc``. 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(8)`'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.
See also ``rndc freeze``.
``trace``
This command increments the server's debugging level by one.
``trace`` *level*
This command sets the server's debugging level to an explicit 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 ``key_id``
without using the configuration file.
Several error messages could be clearer.
See Also
~~~~~~~~
:manpage:`rndc.conf(5)`, :manpage:`rndc-confgen(8)`,
:manpage:`named(8)`, :manpage:`named.conf(5)`, :manpage:`ndc(8)`, BIND 9 Administrator
Reference Manual.