NAME

       dnsdist - A DNS and DoS aware, scriptable loadbalancer

SYNOPSIS

       dnsdist [<option>...] [address]...

DESCRIPTION

       dnsdist  receives  DNS  queries  and  relays  them  to  one or more downstream servers. It
       subsequently sends back responses to the original requestor.

       dnsdist operates over TCP and UDP, and strives to deliver very high performance over both.

       Currently, queries are sent to the downstream server with the least  outstanding  queries.
       This effectively implies load balancing, making sure that slower servers get less queries.

       If  a  reply has not come in after a few seconds, it is removed from the queue, but in the
       short term, timeouts do cause a server to get less traffic.

       IPv4 and IPv6 operation can be mixed and matched, in other words, queries coming  in  over
       IPv6 could be forwarded to IPv4 and vice versa.

       dnsdist is scriptable in Lua, see the dnsdist documentation for more information on this.

SCOPE

       dnsdist  does  not  'think'  about  DNS queries, it restricts itself to measuring response
       times and error codes and routing  questions  accordingly.  It  comes  with  a  very  high
       performance packet-cache.

       The  goal  for  dnsdist  is  to remain simple. If more powerful loadbalancing is required,
       dedicated hardware or software is recommended. Linux Virtual Server for example  is  often
       mentioned.

OPTIONS

       -a <netmask>, --acl <netmask>
              Add netmask to the ACL.

       -C <file>, --config <file>
              Load configuration from file.

       --check-config
              Test  the  configuration  file  (which  may be set with --config or -C) for errors.
              dnsdist will show the errors and exit with a non-zero  exit-code  when  errors  are
              found.

       -c <address>, --client <address>
              Operate  as  a client, connect to dnsdist. This will read the dnsdist configuration
              for the controlSocket statement and connect to it.  When address (with an  optional
              port number) is set, dnsdist will connect to that instead.

       -k <key>, --setkey <key>
              When  operating  as  a client(-c, --client), use key as shared secret to connect to
              dnsdist. This should be the  same  key  that  is  used  on  the  server  (set  with
              setKey()).  Note that this will leak the key into your shell's history and into the
              systems running  process  list.  Only  available  when  dnsdist  is  compiled  with
              libsodium support.

       -e,--execute <command>
              Connect to dnsdist and execute command.

       -h, --help
              Display a helpful message and exit.

       -l,--local <address>
              Bind  to  address,  Supply as many addresses (using multiple --local statements) to
              listen on as required. Specify IPv4 as 0.0.0.0:53 and IPv6 as [::]:53.

       --supervised
              Run in foreground, but do not spawn a console.  Use  this  switch  to  run  dnsdist
              inside a supervisor (use with e.g. systemd and daemontools).

       --disable-syslog
              Disable  logging  to syslog. Use this when running inside a supervisor that handles
              logging (like systemd).

       -u,--uid <uid>
              Change the process user to uid after binding sockets. uid can be a name or number.

       -g,--gid <gid>
              Change the process group to gid after binding sockets. gid Can be a name or number.

       -V, --version
              Show the dnsdist version and exit.

       -v, --verbose
              Be verbose.

       address are any number of downstream DNS servers, in the same syntax as used with --local.
       If the port is not specified, 53 is used.

BUGS

       Right now, the TCP support has some rather arbitrary limits.

RESOURCES

       Website: https://dnsdist.org

AUTHOR

       PowerDNS.COM BV and its contributors

COPYRIGHT

       2015-2019, PowerDNS.COM BV and its contributors

                                           Sep 13, 2021                                DNSDIST(1)