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named(8)                            BIND 9                            named(8)


       named - Internet domain name server


       named  [  [-4]  |  [-6]  ]  [-c  config-file] [-C] [-d debug-level] [-D
       string] [-E engine-name] [-f] [-g] [-L logfile] [-M option]  [-m  flag]
       [-n #cpus] [-p port] [-s] [-t directory] [-U #listeners] [-u user] [-v]
       [-V] [-X lock-file]


       named is a Domain Name System (DNS) server, part of the BIND 9  distri-
       bution  from  ISC.  For  more information on the DNS, see RFC 1033, RFC
       1034, and RFC 1035.

       When invoked without arguments, named reads the  default  configuration
       file /opt/local/etc/named.conf, reads any initial data, and listens for


       -4     This option tells named to use  only  IPv4,  even  if  the  host
              machine is capable of IPv6. -4 and -6 are mutually exclusive.

       -6     This  option  tells  named  to  use  only IPv6, even if the host
              machine is capable of IPv4. -4 and -6 are mutually exclusive.

       -c config-file
              This option tells named to use config-file as its  configuration
              file  instead  of  the  default,  /opt/local/etc/named.conf.  To
              ensure that the configuration file can  be  reloaded  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.

       -C     This  option  prints  out the default built-in configuration and

              NOTE: This is for debugging purposes only and is not an accurate
              representation of the actual configuration used by named at run-

       -d debug-level
              This option sets the daemon's debug level to debug-level. Debug-
              ging  traces  from  named become more verbose as the debug level

       -D string
              This option 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, this option specifies the hardware to  use  for
              cryptographic  operations,  such  as a secure key store used for

              When BIND 9 is built with OpenSSL, this needs to be set  to  the
              OpenSSL engine identifier that drives the cryptographic acceler-
              ator or hardware service module (usually pkcs11).

       -f     This option runs the server in the foreground (i.e., do not dae-

       -g     This  option  runs  the  server in the foreground and forces all
              logging to stderr.

       -L logfile
              This option sets the log to the file logfile by default, instead
              of the system log.

       -M option
              This  option  sets the default memory context options. If set to
              external, the internal memory manager is bypassed  in  favor  of
              system-provided  memory  allocation  functions.  If set to fill,
              blocks of memory are 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
              This  option  turns  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
              This  option  creates  #cpus worker threads to take advantage of
              multiple CPUs. If not specified, named tries  to  determine  the
              number  of CPUs present and creates one thread per CPU. If it is
              unable to determine the number of CPUs, a single  worker  thread
              is created.

       -p value
              This  option specifies the port(s) on which the server will lis-
              ten for queries. If value is of the form <portnum> or dns=<port-
              num>,  the server will listen for DNS queries on portnum; if not
              not specified, the default is port 53. If value is of  the  form
              tls=<portnum>,  the  server will listen for TLS queries on port-
              num; the default is 853.  If value is of the  form  https=<port-
              num>,  the  server will listen for HTTPS queries on portnum; the
              default is 443.  If value is of  the  form  http=<portnum>,  the
              server  will  listen for HTTP queries on portnum; the default is

       -s     This option writes memory usage statistics to stdout on exit.

          This option is mainly of interest to BIND 9 developers  and  may  be
          removed or changed in a future release.

       -S #max-socks
              This option is deprecated and no longer has any function.

          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 sup-
          port the specified number of sockets. Note also that the actual max-
          imum  number  is  normally  slightly fewer than the specified value,
          because named reserves some file descriptors for its internal use.

       -t directory
              This option tells named to chroot to directory after  processing
              the command-line arguments, but before reading the configuration

          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 privi-
          leges to escape a chroot jail.

       -U #listeners
              This  option tells named the number of #listeners worker threads
              to listen on, for incoming UDP packets on each address.  If  not
              specified,  named calculates 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.

       -u user
              This option sets the setuid to user after completing  privileged
              operations,  such  as creating sockets that listen on privileged

          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.

       -v     This option reports the version number and exits.

       -V     This  option  reports  the version number and build options, and

       -X lock-file
              This option acquires 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


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

       SIGHUP This signal forces a reload of the server.

              These signals 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  Refer-
       ence 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.


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


       Internet Systems Consortium


       2022, Internet Systems Consortium

9.18.3                            2022-05-09                          named(8)

bind 9.18.3 - Generated Tue May 24 14:04:36 CDT 2022
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