This plugin checks if the client is listed in RBLs (Real-time Blackhole Lists). These are lists of IP addresses misbehaving. There are many RBLs, some are more aggressive than others. More information at http://en.wikipedia.org/wiki/DNSBL This filter will result in one DNS request for every blocklist that you have configured. This might be problematic for sites under heavy load, although this plugin has been used on high-traffic sites without any problem. One DNS request takes a few miliseconds to complete, after all. INSTALLATION 1. Download dnsbl_check-(version).tar.gz. You agree to the license. 2. Go to your application's 'vendor/plugins' directory 3. Untar (un-winzip) the above file: tar xvfz dnsbl_check.tar.gz 4. Restart your application. VERSION HISTORY 0.1 18 June 2006 Initial release 0.2 10 June 2006 Renamed to dnsbl_check, bugfix 0.3 20 June 2006 Removed sorbs from distribution, was not supposed to be included (too aggressive) 0.4 18 July 2006 Explicit return false added, moved to a per-controller basis (not global anymore) 1.0 16 August 2006 Renamed 0.4 to 1.0. I have been using the plugin very succesfully for months now. 1.1 17 October 2006 Multithreaded version 1.2 23 October 2006 Using the native Ruby resolver library for better multithreaded support 1.2.1 25 October 2006 Accepts a wider range of dns responses 1.2.2 11 December 2006 dnsbls are seemingly under attack, added code to cope with failing service MORE INFORMATION http://spacebabies.nl/dnsbl_check/ joost@spacebabies.nl