named9 Daemon
Purpose
Internet domain name server.
Syntax
named9 [ -4 ] [ -6 ] [ -c config-file ] [ -d debug-level ] [ -f ] [ -g ] [ -n #cpus ] [ -p port ] [ -s ] [-t directory ] [-u user] [ -v ] [ -x cache-file ]
Description
named9 is a Domain Name System (DNS) server, part of the BIND 9 distribution from ISC. For more information on the DNS, see RFCs 1033, 1034, and 1035. When invoked without arguments, the named9 daemon reads the default configuration file /etc/named.conf, reads any initial data, and listens for queries.
Flags
| Item | Description |
|---|---|
| -4 | Uses IPv4 only even if the host machine is capable of IPv6. The -4 and -6 options are mutually exclusive. |
| -6 | Uses IPv6 only even if the host machine is capable of IPv4. The -4 and -6 options are mutually exclusive. |
| -c config-file | Uses config-file as the configuration file instead of the default, /etc/named.conf. To ensure that reloading the configuration file continues to work after the server has changed its working directory due to a possible directory option in the configuration file, the config-file value must be an absolute path name. |
| -d debug-level | Sets the daemon's debug level to the debug-level value. Debugging traces from the named9 daemon become more verbose as the debug level increases. |
| -f | Runs the server in the foreground. |
| -g | Runs the server in the foreground and forces all logging to the standard error stderr. |
| -n #cpus | Creates #cpus worker threads to take advantage of multiple CPUs. If not specified, the named9 daemon tries to determine the number of CPUs present and creates one thread per CPU. If it is unable to determine the number of CPUs, the named9 daemon creates a single worker thread. |
| -p port | Listens for queries on port port. If not specified, the default is port 53. |
| -s | Writes memory usage statistics to the standard output stdout on exit. |
| -t directory | Changes the present directory to the directory
specified after processing the command line arguments, but before
reading the configuration file. Warning: You
must use this option in conjunction with the -u option, as
changing the present directory of a process running as root does not
enhance security on most systems.
|
| -u user | Sets the process user ID to the user specified after completing privileged operations, such as creating sockets that listen on privileged ports. |
| -v | Reports the version number and exit. |
| -x cache-file | Loads data from cache-file into the cache of the default view. |
Signals
In routine operation, you cannot use signals to control the name server; you must use the rndc command.
| Item | Description |
|---|---|
| SIGHUP | Forces a reload of the server. |
| SIGINT, SIGTERM | Shuts down the server. |
The result of sending any other signals to the server is undefined.
Configuration
For a complete description of the named9 configuration file, refer to the BIND 9 Administrator Reference Manual.
Files
| Item | Description |
|---|---|
| /usr/sbin/named9 | Contains the named9 daemon. |
| /etc/named.conf | The default configuration file. |
| /etc/named.pid | The default process-id file. |