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).

       --log-timestamps
              Prepend timestamps to messages logged to standard out.

       -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

       2015-2023, PowerDNS.COM BV and its contributors

                                                  Dec 14, 2023                                        DNSDIST(1)