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.

NLnet Labs                                        Jul 21, 2017                                            NSD(8)