TechTheft

Building a DNSBL

DNSBL are at heart a simple concept. Provide a list of numeric or textual subdomains that map to either IP or domains elsewhere on the internet.

You will need a domain name for the DNSBL seperate from the zone itself.

Our example DNSBL is going to be called example.com.

At http://www.example.com/ the public can read all about our DNSBL, who we are, why it has been setup, etc.

At http://www.example.com/zones.html we provide a list of the Blocklist zones we provide. Including a clear explanation of what is listed, how they are added (automatic of manual etc) and how entries are removed (if at all). What results each zone will return, and what test entries have been setup for others to test the list with. (ie 127.0.0.2 is usually listed).

At http://www.example.com/policy.html we provide a clear explanation of what types of response we will deal with and what will happen to threats, insults, and general abuse of the list maintainers. Some of this may be stated again on the zones page.

At http://www.example.com/listed.html we provide some text for anyone whose mailis bouncing. Covering why they are listed, and what their options are.

At *.dnsbl.example.com we provide the list itself.

NOTE: The site text is all provided as "www." and the list is under "dnsbl.". This is necessary to keep the DNS results seperate. You can get into some real trouble with DNS if the two are mixed.

For some real DNSBL that provide excellent information: