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.
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. If not specified,
the root zone (.) is considered.
- origin name
- Specifies fully qualified domain name suffix which is appended to non-fqd
owners in update commands. The default origin is the root zone.
- 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 0.
- 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.
Dnssec-keygen keyfile format is not supported. Use keymgr(8) instead.
Zone name/server guessing is not supported if the zone name/server is not specified.
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
editrc(5) for details.
Command history is saved in ~/.knsupdate_history.
See Also
kdig(1), khost(1), keymgr(8), editrc(5).