A small and fast DNS daemon especially made to serve DNSBL zones


rbldnsd is a small and fast DNS daemon which is especially made to serve DNSBL zones. rbldnsd is extremely fast - it outperforms both bind and djbdns greatly. It has very small memory footprint.

The daemon can serve both IP-based and name-based blocklists. It has ability to specify individual values for every entry, can serve as many zones on a single IP address as you wish, and, finally, it is a real nameserver: it can reply to DNS metadata requests. The daemon keeps all zones in memory for faster operations, but its memory usage is very efficient, especially for repeated TXT values which are stored only once.

How to get rbldnsd

rbldnsd is open source (GPL v2 or later license).

Source: The last version of the sourcecode is hosted on Github

Direct links to the latest ZIP sources:

Precompiled Packages: rbldnsd is provided as a package by most *nix operating systems.

How to use rbldnsd

A few examples of zonefiles and general usage are on the documentation page.

The manpage of the latest stable release of rbldnsd is rbldnsd.8

History & future

rbldnsd was originally developed by Michael Tokarev, inspired by Dan J. Bernstein's rbldns program found in the djbdns package.
Since version 0.998, released 31 Dec 2015, the stewardship of the project was moved to The Spamhaus Project.
Spamhaus will keep maintaining the code, while working towards a new version of the software with additional features and improvements.


There is a mailing list available for developers and users.


Changelog and recent news.