Unbound is a validating, recursive, caching DNS resolver. It is designed to be fast and lean and incorporates modern features based on open standards. If you have any feedback, we would love to hear from you. Don’t hesitate to create an issue on Github or post a message on our community forum. You can learn more about Unbound by reading our documentation.

Make sure you have the C toolchain, OpenSSL and its include files, and libexpat installed. If building from the repository source you also need flex and bison installed. Unbound can be compiled and installed using:

./configure && make && make install

You can use libevent if you want. libevent is useful when using many (e.g., 10000) outgoing ports. Use the --with-libevent configure option to compile Unbound with libevent support.

If not, the default builtin alternative opens max 256 ports at the same time and is equally capable and a little faster.

All of Unbound's configuration options are described in the unbound.conf(5) man page, which will be installed and is also available on the Unbound documentation page for the latest version.

An example configuration file, with minimal documentation, is located in doc/example.conf.