1.. 2 WHEN EDITING MAKE SURE EACH SENTENCE STARTS ON A NEW LINE 3 4.. 5 IT HELPS RENDERERS TO DO THE RIGHT THING WRT SPACE 6 7.. 8 IT HELPS PEOPLE DIFFING THE CHANGES 9 10.. 11 WHEN EDITING MAKE SURE EACH SENTENCE STARTS ON A NEW LINE 12 13.. 14 IT HELPS RENDERERS TO DO THE RIGHT THING WRT SPACE 15 16.. 17 IT HELPS PEOPLE DIFFING THE CHANGES 18 19.. 20 WHEN EDITING MAKE SURE EACH SENTENCE STARTS ON A NEW LINE 21 22.. 23 IT HELPS RENDERERS TO DO THE RIGHT THING WRT SPACE 24 25.. 26 IT HELPS PEOPLE DIFFING THE CHANGES 27 28.. 29 WHEN EDITING MAKE SURE EACH SENTENCE STARTS ON A NEW LINE 30 31.. 32 IT HELPS RENDERERS TO DO THE RIGHT THING WRT SPACE 33 34.. 35 IT HELPS PEOPLE DIFFING THE CHANGES 36 37.. program:: unbound 38 39unbound(8) 40========== 41 42Synopsis 43-------- 44 45**unbound** [``-hdpv``] [``-c <cfgfile>``] 46 47Description 48----------- 49 50``unbound`` is a caching DNS resolver. 51 52It uses a built in list of authoritative nameservers for the root zone (``.``), 53the so called root hints. 54On receiving a DNS query it will ask the root nameservers for an answer and 55will in almost all cases receive a delegation to a top level domain (TLD) 56authoritative nameserver. 57It will then ask that nameserver for an answer. 58It will recursively continue until an answer is found or no answer is available 59(NXDOMAIN). 60For performance and efficiency reasons that answer is cached for a certain time 61(the answer's time-to-live or TTL). 62A second query for the same name will then be answered from the cache. 63Unbound can also do DNSSEC validation. 64 65To use a locally running Unbound for resolving put: 66 67.. code-block:: text 68 69 nameserver 127.0.0.1 70 71into *resolv.conf(5)*. 72 73If authoritative DNS is needed as well using :external+nsd:doc:`manpages/nsd`, 74careful setup is required because authoritative nameservers and resolvers are 75using the same port number (53). 76 77The available options are: 78 79.. option:: -h 80 81 Show the version number and commandline option help, and exit. 82 83.. option:: -c <cfgfile> 84 85 Set the config file with settings for unbound to read instead of reading the 86 file at the default location, :file:`@ub_conf_file@`. 87 The syntax is described in :doc:`unbound.conf(5)</manpages/unbound.conf>`. 88 89.. option:: -d 90 91 Debug flag: do not fork into the background, but stay attached to the 92 console. 93 This flag will also delay writing to the log file until the thread-spawn 94 time, so that most config and setup errors appear on stderr. 95 If given twice or more, logging does not switch to the log file or to 96 syslog, but the log messages are printed to stderr all the time. 97 98.. option:: -p 99 100 Don't use a pidfile. 101 This argument should only be used by supervision systems which can ensure 102 that only one instance of Unbound will run concurrently. 103 104.. option:: -v 105 106 Increase verbosity. 107 If given multiple times, more information is logged. 108 This is in addition to the verbosity (if any) from the config file. 109 110.. option:: -V 111 112 Show the version number and build options, and exit. 113 114See Also 115-------- 116 117:doc:`unbound.conf(5)</manpages/unbound.conf>`, 118:doc:`unbound-checkconf(8)</manpages/unbound-checkconf>`, 119:external+nsd:doc:`manpages/nsd`. 120