DNSDIST(1)                          dnsdist                         DNSDIST(1)

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 or libcrypto 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
       PowerDNS.COM BV and its contributors

                                October 3, 2024                     DNSDIST(1)