NSD(8)                            NSD 4.1.15                            NSD(8)



NAME
       nsd - Name Server Daemon (NSD) version 4.1.15.

SYNOPSIS
       nsd [-4] [-6] [-a ip-address[@port]] [-c configfile] [-d] [-f database]
       [-h] [-i identity] [-I nsid] [-l logfile] [-N server-count] [-n noncur-
       rent-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 cre-
       ated 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  com-
       piled 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  com-
       mandline,  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 sys-
       tem 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/db/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 han-
              dled by each server. The default is 100.

       -P pidfile
              Use the specified  pidfile  instead  of  the  platform  specific
              default,  which  is  mostly /var/run/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  bind-
              ing  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)  log-
              ging.  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/db/nsd/nsd.db"
              default NSD database

       /var/run/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  facil-
       ity, 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 CRED-
       ITS file in the distribution for further details.



NLnet Labs                       Feb 16, 2017                           NSD(8)

Thu Feb 16 2017

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