.. highlight:: none

``knsupdate`` – Dynamic DNS update utility
==========================================

Synopsis
--------

:program:`knsupdate` [*options*] [*filename*]

Description
-----------

This utility sends Dynamic DNS update messages to a DNS server. Update content
is read from a file (if the parameter *filename* is given) or from the standard
input.

The format of updates is textual and is made up of commands. Every command is
placed on the separate line of the input. Lines starting with a semicolon are
comments and are not processed.

Parameters
..........

*filename*
  Path to the file with knsupdate commands.

Options
.......

**-d**
  Enable debug messages.

**-h**, **--help**
  Print the program help.

**-k** *keyfile*
  Use the TSIG key stored in a file *keyfile* to authenticate the request. The
  file should contain the key in the same format, which is accepted by the
  **-y** option.

**-p** *port*
  Set the port to use for connections to the server (if not explicitly specified
  in the update). The default is 53.

**-r** *retries*
  The number of retries for UDP requests. The default is 3.

**-t** *timeout*
  The total timeout (for all UDP update tries) of the update request in seconds.
  The default is 12. If set to zero, the timeout is infinite.

**-v**
  Use a TCP connection.

**-V**, **--version**
  Print the program version.

**-y** [*alg*:]\ *name*:*key*
  Use the TSIG key with a name *name* to authenticate the request. The *alg*
  part specifies the algorithm (the default is hmac-sha256) and *key* specifies
  the shared secret encoded in Base64.

Commands
........

**server** *name* [*port*]
  Specifies a receiving server of the dynamic update message. The *name* parameter
  can be either a host name or an IP address. If the *port* is not specified,
  the default port is used. The default port value can be controlled using
  the **-p** program option.

**local** *address* [*port*]
  Specifies outgoing *address* and *port*. If no local is specified, the
  address and port are set by the system automatically. The default port number
  is 0.

**zone** *name*
  Specifies that all updates are done within a zone *name*. The zone name doesn't
  have a default and must be set explicitly.

**origin** *name*
  Specifies fully qualified domain name suffix which is appended to non-fqd
  owners in update commands. The default is the terminal label (**.**).

**class** *name*
  Sets *name* as the default class for all updates. If not used, the default
  class is IN.

**ttl** *value*
  Sets *value* as the default TTL (in seconds). If not used, the default value
  is 3600.

**key** [*alg*:]\ *name* *key*
  Specifies the TSIG *key* named *name* to authenticate the request. An optional
  *alg* algorithm can be specified. This command has the same effect as
  the program option **-y**.

[**prereq**] **nxdomain** *name*
  Adds a prerequisite for a non-existing record owned by *name*.

[**prereq**] **yxdomain** *name*
  Adds a prerequisite for an existing record owned by *name*.

[**prereq**] **nxrrset** *name* [*class*] *type*
  Adds a prerequisite for a non-existing record of the *type* owned by *name*.
  Internet *class* is expected.

[**prereq**] **yxrrset** *name* [*class*] *type* [*data*]
  Adds a prerequisite for an existing record of the *type* owned by *name*
  with optional *data*. Internet *class* is expected.

[**update**] **add** *name* [*ttl*] [*class*] *type* *data*
  Adds a request to add a new resource record into the zone.
  Please note that if the *name* is not fully qualified domain name, the
  current origin name is appended to it.

[**update**] **del**\[**ete**] *name* [*ttl*] [*class*] [*type*] [*data*]
  Adds a request to remove all (or matching *class*, *type* or *data*)
  resource records from the zone. There is the same requirement for the *name*
  parameter as in **update add** command. The *ttl* item is ignored.

**show**
  Displays current content of the update message.

**send**
  Sends the current update message and cleans the list of updates.

**answer**
  Displays the last answer from the server.

**debug**
  Enable debugging. This command has the same meaning as the **-d** program option.

**exit**
  End the program.

Notes
-----

Options **-k** and **-y** can not be used simultaneously.

Neither `tsig-keygen(8)` nor `dnssec-keygen(1)` keyfile formats are supported.
Use :manpage:`keymgr(8)` to construct a string for **-y** or the file passed to **-k**.

Zone name/server guessing is not supported if the zone name/server is not specified.

An empty line doesn't send the update.

Interactive mode
................

The utility provides interactive mode with basic line editing functionality,
command completion, and command history.

Interactive mode behavior can be customized in `~/.editrc`. Refer to
:manpage:`editrc(5)` for details.

Command history is saved in `~/.knsupdate_history`.

Exit values
-----------

Exit status of 0 means successful operation. Any other exit status indicates
an error.

Examples
--------

1. Send one update of the zone example.com to the server 192.168.1.1. The update
   contains two new records::

     $ knsupdate
     knsupdate> server 192.168.1.1
     knsupdate> zone example.com.
     knsupdate> origin example.com.
     knsupdate> ttl 3600
     knsupdate> add test1.example.com. 7200 A 192.168.2.2
     knsupdate> add test2 TXT "hello"
     knsupdate> show
     knsupdate> send
     knsupdate> answer
     knsupdate> exit

See Also
--------

:manpage:`kdig(1)`, :manpage:`khost(1)`, :manpage:`keymgr(8)`, :manpage:`editrc(5)`.