NAME¶named - Internet domain name server
SYNOPSIS¶named [ [-4] | [-6] ] [-c config-file] [-d debug-level] [-D string] [-E engine-name] [-f] [-g] [-L logfile] [-M option] [-m flag] [-n #cpus] [-p port] [-s] [-S #max-socks] [-t directory] [-U #listeners] [-u user] [-v] [-V] [-X lock-file] [-x cache-file]
DESCRIPTION¶named is a Domain Name System (DNS) server, part of the BIND 9 distribution from ISC. For more information on the DNS, see RFC 1033, RFC 1034, and RFC 1035.
When invoked without arguments, named will read the default configuration file /etc/named.conf, read any initial data, and listen for queries.
- 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.
- -D string
- Specifies a string that is used to identify a instance of named in a process listing. The contents of string are not examined.
- -E engine-name
- When applicable, specifies the hardware to use for cryptographic
operations, such as a secure key store used for signing.
When BIND is built with OpenSSL PKCS#11 support, this defaults to the string "pkcs11", which identifies an OpenSSL engine that can drive a cryptographic accelerator or hardware service module. When BIND is built with native PKCS#11 cryptography (--enable-native-pkcs11), it defaults to the path of the PKCS#11 provider library specified via "--with-pkcs11".
- Run the server in the foreground (i.e. do not daemonize).
- Run the server in the foreground and force all logging to stderr.
- -L logfile
- Log to the file logfile by default instead of the system log.
- -M option
- Sets the default memory context options. If set to external, this causes the internal memory manager to be bypassed in favor of system-provided memory allocation functions. If set to fill, blocks of memory will be filled with tag values when allocated or freed, to assist debugging of memory problems. (nofill disables this behavior, and is the default unless named has been compiled with developer options.)
- -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>.
- -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.
- -S #max-socks
- Allow named to use up to #max-socks sockets. The default value is 21000 on systems built with default configuration options, and 4096 on systems built with "configure --with-tuning=small".
- -t directory
- Chroot to directory after processing the command line arguments, but before reading the configuration file.
- -U #listeners
- Use #listeners worker threads to listen for incoming UDP packets on each address. If not specified, named will calculate a default value based on the number of detected CPUs: 1 for 1 CPU, and the number of detected CPUs minus one for machines with more than 1 CPU. This cannot be increased to a value higher than the number of CPUs. If -n has been set to a higher value than the number of detected CPUs, then -U may be increased as high as that value, but no higher. On Windows, the number of UDP listeners is hardwired to 1 and this option has no effect.
- -u user
- Setuid to user after completing privileged operations, such as creating sockets that listen on privileged ports.
- Report the version number and exit.
- Report the version number and build options, and exit.
- -X lock-file
- Acquire a lock on the specified file at runtime; this helps to prevent duplicate named instances from running simultaneously. Use of this option overrides the lock-file option in named.conf. If set to none, the lock file check is disabled.
- -x cache-file
- Load data from cache-file into the cache of the default view.
SIGNALS¶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.
CONFIGURATION¶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 inherits the umask (file creation mode mask) from the parent process. If files created by named, such as journal files, need to have custom permissions, the umask should be set explicitly in the script used to start the named process.
- The default configuration file.
- The default process-id file.
SEE ALSO¶RFC 1033, RFC 1034, RFC 1035, named-checkconf(8), named-checkzone(8), rndc(8), :manpage:`named.conf(5), BIND 9 Administrator Reference Manual.
AUTHOR¶Internet Systems Consortium
COPYRIGHT¶2020, Internet Systems Consortium