NAME

       unbound - Unbound DNS validating resolver 1.9.4.

SYNOPSIS

       unbound [-h] [-d] [-p] [-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 continue
       until  an  answer  is  found  or  no  answer is available (NXDOMAIN).  For performance and
       efficiency reasons that answer is cached for a certain 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 number and commandline option help, and exit.

       -c cfgfile
              Set  the  config file with settings for unbound to read instead of reading the file
              at the default location, /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.

       -p     Don't  use  a  pidfile.   This  argument should only be used by supervision systems
              which can ensure that only one instance of unbound will run concurrently.

       -v     Increase verbosity. If given multiple times, more information is logged.   This  is
              in addition to the verbosity (if any) from the config file.

       -V     Show the version number and build options, and exit.

SEE ALSO

       unbound.conf(5), unbound-checkconf(8), nsd(8).

AUTHORS

       Unbound developers are mentioned in the CREDITS file in the distribution.