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 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.

OPTIONS

       -4
           Use IPv4 only even if the host machine is capable of IPv6.  -4 and -6 are mutually
           exclusive.

       -6
           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".

       -f
           Run the server in the foreground (i.e. do not daemonize).

       -g
           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. Currently the only supported option is
           external, which causes the internal memory manager to be bypassed in favor of
           system-provided memory allocation functions.

       -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.

       -s
           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.

       -S #max-socks
           Allow named to use up to #max-socks sockets. The default value is 4096 on systems
           built with default configuration options, and 21000 on systems built with "configure
           --with-tuning=large".

               Warning
               This option should be unnecessary for the vast majority of users. The use of this
               option could even be harmful because the specified value may exceed the limitation
               of the underlying system API. It is therefore set only when the default
               configuration causes exhaustion of file descriptors and the operational
               environment is known to support the specified number of sockets. Note also that
               the actual maximum number is normally a little fewer than the specified value
               because named reserves some file descriptors for its internal use.

       -t directory
           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(2) is defined allows a process with root privileges to escape a chroot
               jail.

       -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.

               Note
               On Linux, named uses the kernel's capability mechanism to drop all root privileges
               except the ability to bind(2) 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(2).

       -v
           Report the version number and exit.

       -V
           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.

               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.

SIGNALS

       In routine operation, signals should not be used to control the nameserver; rndc should be
       used instead.

       SIGHUP
           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.

FILES

       /etc/named.conf
           The default configuration file.

       /var/run/named/named.pid
           The default process-id file.

SEE ALSO

       RFC 1033, RFC 1034, RFC 1035, named-checkconf(8), named-checkzone(8), rndc(8), lwresd(8),
       named.conf(5), BIND 9 Administrator Reference Manual.

AUTHOR

       Internet Systems Consortium, Inc.

COPYRIGHT

       Copyright © 2000, 2001, 2003-2009, 2011, 2013-2017 Internet Systems Consortium, Inc.
       ("ISC")