NAME

       nsd - Name Server Daemon (NSD) version 4.1.17.

SYNOPSIS

       nsd [-4] [-6] [-a ip-address[@port]] [-c configfile] [-d] [-f database] [-h] [-i identity]
       [-I nsid] [-l logfile] [-N server-count] [-n noncurrent-tcp-count] [-P pidfile] [-p  port]
       [-s seconds] [-t chrootdir] [-u username] [-V level] [-v]

DESCRIPTION

       NSD  is  a  complete implementation of an authoritative DNS nameserver.  Upon startup, NSD
       will read the database specified with -f database argument and put itself into  background
       and  answers  queries  on  port  53 or a different port specified with -p port option. The
       database is created if it does  not  exist.  By  default,  NSD  will  bind  to  all  local
       interfaces  available.  Use the -a ip-address[@port] option to specify a single particular
       interface address to be bound. If this option is given more than once, NSD will  bind  its
       UDP  and TCP sockets to all the specified ip-addresses separately. If IPv6 is enabled when
       NSD is compiled an IPv6 address can also be specified.

OPTIONS

       All the options can be specified in the configfile ( -c argument), except for the  -v  and
       -h  options.  If  options are specified on the commandline, the options on the commandline
       take precedence over the options in the configfile.

       Normally NSD should be started with the `nsd-control(8)  start`  command  invoked  from  a
       /etc/rc.d/nsd.sh script or similar at the operating system startup.

       -4     Only listen to IPv4 connections.

       -6     Only listen to IPv6 connections.

       -a ip-address[@port]
              Listen  to  the  specified ip-address.  The ip-address must be specified in numeric
              format (using the standard IPv4 or IPv6 notation). Optionally, a port number can be
              given.   This  flag  can  be  specified  multiple  times  to  listen to multiple IP
              addresses. If this flag is not specified, NSD listens to the wildcard interface.

       -c configfile
              Read specified configfile instead of the  default  /etc/nsd/nsd.conf.   For  format
              description see nsd.conf(5).

       -d     Do not fork, stay in the foreground.

       -f database
              Use  the  specified database instead of the default of '/var/lib/nsd/nsd.db'.  If a
              zonesdir: is specified in the config  file  this  path  can  be  relative  to  that
              directory.

       -h     Print help information and exit.

       -i identity
              Return  the specified identity when asked for CH TXT ID.SERVER (This option is used
              to determine which server is answering the queries  when  they  are  anycast).  The
              default is the name returned by gethostname(3).

       -I nsid
              Add  the specified nsid to the EDNS section of the answer when queried with an NSID
              EDNS enabled packet.  As a sequence of hex characters or  with  ascii_  prefix  and
              then an ascii string.

       -l logfile
              Log messages to the specified logfile.  The default is to log to stderr and syslog.
              If a zonesdir: is specified in the config file this path can be  relative  to  that
              directory.

       -N count
              Start  count  NSD  servers. The default is 1. Starting more than a single server is
              only useful on machines with multiple CPUs and/or network adapters.

       -n number
              The maximum number of concurrent TCP connection that can be handled by each server.
              The default is 100.

       -P pidfile
              Use the specified pidfile instead of the platform specific default, which is mostly
              /run/nsd/nsd.pid.  If a zonesdir: is specified in the config file, this path can be
              relative to that directory.

       -p port
              Answer the queries on the specified port.  Normally this is port 53.

       -s seconds
              Produce  statistics dump every seconds seconds. This is equal to sending SIGUSR1 to
              the daemon periodically.

       -t chroot
              Specifies a directory to chroot to upon startup. This option requires you to ensure
              that  appropriate  syslogd(8)  socket  (e.g.   chrootdir  /dev/log)  is  available,
              otherwise NSD won't produce any log output.

       -u username
              Drop user and group privileges to those of username after binding the socket.   The
              username must be one of: username, id, or id.gid. For example: nsd, 80, or 80.80.

       -V level
              This value specifies the verbosity level for (non-debug) logging.  Default is 0.

       -v     Print the version number of NSD to standard error and exit.

       NSD reacts to the following signals:

       SIGTERM
              Stop answering queries, shutdown, and exit normally.

       SIGHUP Reload.   Scans  zone files and if changed (mtime) reads them in.  Also reopens the
              logfile (assists logrotation).

       SIGUSR1
              Dump BIND8-style statistics into the log. Ignored otherwise.

FILES

       "/var/lib/nsd/nsd.db"
              default NSD database

       /run/nsd/nsd.pid
              the process id of the name server.

       /etc/nsd/nsd.conf
              default NSD configuration file

DIAGNOSTICS

       NSD will log all the problems via the standard syslog(8) daemon facility,  unless  the  -d
       option is specified.

SEE ALSO

       nsd.conf(5), nsd-checkconf(8), nsd-control(8)

AUTHORS

       NSD  was  written  by  NLnet  Labs and RIPE NCC joint team. Please see CREDITS file in the
       distribution for further details.