1NSD(8) NSD 4.3.9 NSD(8)
2
6 nsd - Name Server Daemon (NSD) version 4.3.9.
7
9 nsd [-4] [-6] [-a ip-address[@port]] [-c configfile] [-d] [-f database]
10 [-h] [-i identity] [-I nsid] [-l logfile] [-N server-count] [-n noncur‐
11 rent-tcp-count] [-P pidfile] [-p port] [-s seconds] [-t chrootdir] [-u
12 username] [-V level] [-v]
13
15 NSD is a complete implementation of an authoritative DNS nameserver.
16 Upon startup, NSD will read the database specified with -f database ar‐
17 gument and put itself into background and answers queries on port 53 or
18 a different port specified with -p port option. The database is created
19 if it does not exist. By default, NSD will bind to all local interfaces
20 available. Use the -a ip-address[@port] option to specify a single par‐
21 ticular interface address to be bound. If this option is given more
22 than once, NSD will bind its UDP and TCP sockets to all the specified
23 ip-addresses separately. If IPv6 is enabled when NSD is compiled an
24 IPv6 address can also be specified.
25
27 All the options can be specified in the configfile ( -c argument), ex‐
28 cept for the -v and -h options. If options are specified on the comman‐
29 dline, the options on the commandline take precedence over the options
30 in the configfile.
31 Normally NSD should be started with the `nsd-control(8) start` command
33 invoked from a /etc/rc.d/nsd.sh script or similar at the operating sys‐
34 tem startup.
35 -4 Only listen to IPv4 connections.
37 -6 Only listen to IPv6 connections.
39 -a ip-address[@port]
41 Listen to the specified ip-address. The ip-address must be
42 specified in numeric format (using the standard IPv4 or IPv6 no‐
43 tation). Optionally, a port number can be given. This flag can
44 be specified multiple times to listen to multiple IP addresses.
45 If this flag is not specified, NSD listens to the wildcard in‐
46 terface.
47 -c configfile
49 Read specified configfile instead of the default
50 /etc/nsd/nsd.conf. For format description see nsd.conf(5).
51 -d Do not fork, stay in the foreground.
53 -f database
55 Use the specified database instead of the default of ''. If a
56 zonesdir: is specified in the config file this path can be rela‐
57 tive to that directory.
58 -h Print help information and exit.
60 -i identity
62 Return the specified identity when asked for CH TXT ID.SERVER
63 (This option is used to determine which server is answering the
64 queries when they are anycast). The default is the name returned
65 by gethostname(3).
66 -I nsid
68 Add the specified nsid to the EDNS section of the answer when
69 queried with an NSID EDNS enabled packet. As a sequence of hex
70 characters or with ascii_ prefix and then an ascii string.
71 -l logfile
73 Log messages to the specified logfile. The default is to log to
74 stderr and syslog. If a zonesdir: is specified in the config
75 file this path can be relative to that directory.
76 -N count
78 Start count NSD servers. The default is 1. Starting more than a
79 single server is only useful on machines with multiple CPUs
80 and/or network adapters.
81 -n number
83 The maximum number of concurrent TCP connection that can be han‐
84 dled by each server. The default is 100.
85 -P pidfile
87 Use the specified pidfile instead of the platform specific de‐
88 fault, which is mostly . If a zonesdir: is specified in the
89 config file, this path can be relative to that directory.
90 -p port
92 Answer the queries on the specified port. Normally this is port
93 53.
94 -s seconds
96 Produce statistics dump every seconds seconds. This is equal to
97 sending SIGUSR1 to the daemon periodically.
98 -t chroot
100 Specifies a directory to chroot to upon startup. This option re‐
101 quires you to ensure that appropriate syslogd(8) socket (e.g.
102 chrootdir /dev/log) is available, otherwise NSD won't produce
103 any log output.
104 -u username
106 Drop user and group privileges to those of username after bind‐
107 ing the socket. The username must be one of: username, id, or
108 id.gid. For example: nsd, 80, or 80.80.
109 -V level
111 This value specifies the verbosity level for (non-debug) log‐
112 ging. Default is 0.
113 -v Print the version number of NSD to standard error and exit.
115 NSD reacts to the following signals:
117 SIGTERM
119 Stop answering queries, shutdown, and exit normally.
120 SIGHUP Reload. Scans zone files and if changed (mtime) reads them in.
122 Also reopens the logfile (assists logrotation).
123 SIGUSR1
125 Dump BIND8-style statistics into the log. Ignored otherwise.
126
128 "" default NSD database
129 the process id of the name server.
132 /etc/nsd/nsd.conf
134 default NSD configuration file
135
137 NSD will log all the problems via the standard syslog(8) daemon facil‐
138 ity, unless the -d option is specified.
139
141 nsd.conf(5), nsd-checkconf(8), nsd-control(8)
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144 NSD was written by NLnet Labs and RIPE NCC joint team. Please see CRED‐
145 ITS file in the distribution for further details.
146NLnet Labs Dec 9, 2021 NSD(8)