unbound(8)unbound 1.5.5 unbound(8)NAMEunbound - Unbound DNS validating resolver 1.5.5.
SYNOPSISunbound [-h] [-d] [-v] [-c cfgfile]
DESCRIPTION
Unbound is a caching DNS resolver.
It uses a built in list of authoritative nameservers for the root zone
(.), the so called root hints. On receiving a DNS query it will ask
the root nameservers for an answer and will in almost all cases receive
a delegation to a top level domain (TLD) authoritative nameserver. It
will then ask that nameserver for an answer. It will recursively con‐
tinue until an answer is found or no answer is available (NXDOMAIN).
For performance and efficiency reasons that answer is cached for a cer‐
tain time (the answer's time-to-live or TTL). A second query for the
same name will then be answered from the cache. Unbound can also do
DNSSEC validation.
To use a locally running Unbound for resolving put
nameserver 127.0.0.1
into resolv.conf(5).
If authoritative DNS is needed as well using nsd(8), careful setup is
required because authoritative nameservers and resolvers are using the
same port number (53).
The available options are:
-h Show the version and commandline option help.
-c cfgfile
Set the config file with settings for unbound to read instead of
reading the file at the default location,
/usr/local/etc/unbound/unbound.conf. The syntax is described in
unbound.conf(5).
-d Debug flag: do not fork into the background, but stay attached
to the console. This flag will also delay writing to the log
file until the thread-spawn time, so that most config and setup
errors appear on stderr. If given twice or more, logging does
not switch to the log file or to syslog, but the log messages
are printed to stderr all the time.
-v Increase verbosity. If given multiple times, more information is
logged. This is in addition to the verbosity (if any) from the
config file.
SEE ALSOunbound.conf(5), unbound-checkconf(8), nsd(8).
AUTHORS
Unbound developers are mentioned in the CREDITS file in the distribu‐
tion.
NLnet Labs Oct 6, 2015 unbound(8)
