NSD(8) NSD 4.1.7 NSD(8)NAMEnsd - Name Server Daemon (NSD) version 4.1.7.
SYNOPSISnsd [-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
/usr/local/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/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/nsd.pid
the process id of the name server.
/usr/local/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 ALSOnsd.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 Dec 10, 2015 NSD(8)
