NAME
nsd - Name Server Daemon (NSD) version 3.2.5.
SYNOPSIS
nsd [-4] [-6] [-a ip-address] [-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 must be
generated beforehand with zonec(8). By default, NSD will bind to all
local interfaces available. Use the -a ip-address 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 ‘nsdc(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
Listen to the specified ip-address. The ip-address must be
specified in numeric format (using the standard IPv4 or IPv6
notation). This flag can be specified multiple times to listen
to multiple IP addresses. If this flag is not specified, NSD
listens to all IP addresses.
-c configfile
Read specified configfile instead of the default
/etc/nsd/nsd.conf. For format description see nsd.conf(5).
-d Turn on debugging mode, 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 multicast). 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.
-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 10.
-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
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 the database.
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
will log all the problems via the standard syslog(8) daemon facility,
unless the -d option is specified.
SEE ALSO
nsdc(8), nsd.conf(5), nsd-checkconf(8), nsd-notify(8), nsd-patch(8),
nsd-xfer(8), zonec(8)
AUTHORS
NSD was written by NLnet Labs and RIPE NCC joint team. Please see
CREDITS file in the distribution for further details.
BUGS
NSD will answer the queries erroneously if the database was not
properly compiled with zonec(8). Therefore problems with misconfigured
master zone files or zonec(8) bugs may not be visible until the queries
are actually answered with NSD.