Updated: 2021/Apr/14

unbound(8)                      unbound 1.13.1                      unbound(8)

       unbound - Unbound DNS validating resolver 1.13.1.

       unbound [-h] [-d] [-p] [-v] [-c cfgfile]

       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


       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

       -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.

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

       Unbound developers are mentioned in the CREDITS file in the

NLnet Labs                       Feb  9, 2021                       unbound(8)