named - Internet domain name server
named [-4] [-6] [-c config-file] [-d debug-level] [-f] [-g] [-i pid-file] [-m flag] [-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 fork into two processes for privilege separation, chroot(2) to /var/named, read the default configuration file /var/named/etc/named.conf, read any initial data, and listen for queries. The privileged process will communicate with the child and bind(2) to privileged ports on its behalf. See CAVEATS section below.
- Use IPv4 only even if the host machine is capable of IPv6. -4 and -6 are mutually exclusive.
- Use IPv6 only even if the host machine is capable of IPv4. -4 and -6 are mutually exclusive.
- -c config-file
- 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.
- -d debug-level
- 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.
- -m flag
- Turn on memory usage debugging flags. Possible flags are usage, trace, record, size, and mctx. These correspond to the ISC_MEM_DEBUGXXXX flags described in <isc/mem.h>.
- -i pid-file
- Specifies the file that contains the process ID of named. The default is /var/run/named.pid.
- -n #cpus
- 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.
- -p port
- Listen for queries on port port. If not specified, the default is port 53.
- Write memory usage statistics to stdout on exit.
- -t directory
- Chroot to directory after processing the command line arguments, but before reading the configuration file.
- -u user
- Setuid to user after completing privileged operations, such as creating sockets that listen on privileged ports.
- Report the version number and exit.
- -x cache-file
- Load data from cache-file into the cache of the default view.
In routine operation, signals should not be used to control the nameserver; rndc should be used instead.
- Force a reload of the server.
- SIGINT, SIGTERM
- 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.
named runs privilege separated for binding the privileged ports after an interface or address change. The privileged process will only allow named to bind(2) to default ports. Make sure you use unprivileged (>1024) ports if you change any of the default ports in named's configuration or on the command-line.
- The default configuration file.
- The default process-id file.
RFC 1033, RFC 1034, RFC 1035, named-checkconf(8), named-checkzone(8), rndc(8), lwresd(8), named.conf(5), BIND 9 Administrator Reference Manual.
Internet Systems Consortium