1unbound(8) unbound 1.6.6 unbound(8)
2
3
4
6 unbound - Unbound DNS validating resolver 1.6.6.
7
9 unbound [-h] [-d] [-p] [-v] [-c cfgfile]
10
12 Unbound is a caching DNS resolver.
13
14 It uses a built in list of authoritative nameservers for the root zone
15 (.), the so called root hints. On receiving a DNS query it will ask
16 the root nameservers for an answer and will in almost all cases receive
17 a delegation to a top level domain (TLD) authoritative nameserver. It
18 will then ask that nameserver for an answer. It will recursively con‐
19 tinue until an answer is found or no answer is available (NXDOMAIN).
20 For performance and efficiency reasons that answer is cached for a cer‐
21 tain time (the answer's time-to-live or TTL). A second query for the
22 same name will then be answered from the cache. Unbound can also do
23 DNSSEC validation.
24
25 To use a locally running Unbound for resolving put
26
27 nameserver 127.0.0.1
28
29 into resolv.conf(5).
30
31 If authoritative DNS is needed as well using nsd(8), careful setup is
32 required because authoritative nameservers and resolvers are using the
33 same port number (53).
34
35 The available options are:
36
37 -h Show the version and commandline option help.
38
39 -c cfgfile
40 Set the config file with settings for unbound to read instead of
41 reading the file at the default location,
42 /etc/unbound/unbound.conf. The syntax is described in
43 unbound.conf(5).
44
45 -d Debug flag: do not fork into the background, but stay attached
46 to the console. This flag will also delay writing to the log
47 file until the thread-spawn time, so that most config and setup
48 errors appear on stderr. If given twice or more, logging does
49 not switch to the log file or to syslog, but the log messages
50 are printed to stderr all the time.
51
52 -p Don't use a pidfile. This argument should only be used by
53 supervision systems which can ensure that only one instance of
54 unbound will run concurrently.
55
56 -v Increase verbosity. If given multiple times, more information is
57 logged. This is in addition to the verbosity (if any) from the
58 config file.
59
61 unbound.conf(5), unbound-checkconf(8), nsd(8).
62
64 Unbound developers are mentioned in the CREDITS file in the distribu‐
65 tion.
66
67
68
69NLnet Labs Sep 18, 2017 unbound(8)