named [-c config-file] [-d debug-level] [-f] [-g] [-n #cpus] [-p port] [-s] [-t directory] [-u user] [-v] [-x cache-file]
named 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, named will read the default configuration file /etc/named.conf, read any initial data, and listen for queries.
Use 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 to a possible directory option in the configuration file, config-file should be an absolute pathname.
Set the daemon's debug level to debug-level. Debugging traces from named become more verbose as the debug level increases.
Run the server in the foreground (i.e. do not daemonize).
Run the server in the foreground and force all logging to stderr.
Create #cpus worker threads to take advantage of multiple CPUs. If not specified, named will try to determine the number of CPUs present and create one thread per CPU. If it is unable to determine the number of CPUs, a single worker thread will be created.
Listen for queries on port port. If not specified, the default is port 53.
Write memory usage statistics to stdout on exit.
Note: This option is mainly of interest to BIND 9 developers and may be removed or changed in a future release.
chroot() to directory after processing the command line arguments, but before reading the configuration file.
| Warning |
This option should be used in conjunction with the -u option, as chrooting a process running as root doesn't enhance security on most systems; the way chroot() is defined allows a process with root privileges to escape a chroot jail. |
setuid() to user after completing privileged operations, such as creating sockets that listen on privileged ports.
Note: On Linux, named uses the kernel's capability mechanism to drop all root privileges except the ability to bind() to a privileged port and set process resource limits. Unfortunately, this means that the -u option only works when named is run on kernel 2.2.18 or later, or kernel 2.3.99-pre3 or later, since previous kernels did not allow privileges to be retained after setuid().
Report the version number and exit.
Load data from cache-file into the cache of the default view.
| Warning |
This option must not be used. It is only of interest to BIND 9 developers and may be removed or changed in a future release. |
In routine operation, signals should not be used to control the nameserver; rndc should be used instead.
Force a reload of the server.
Shut down the server.
The result of sending any other signals to the server is undefined.
The named configuration file is too complex to describe in detail here. A complete description is provided in the BIND 9 Administrator Reference Manual.