This service will look into a database (compiled 2010-05-20) of tested open recursive DNS-servers.
Type in an IP-address you want to check and it will check the whole class C net (255 IP-numbers) for a match or the whole net block if we can find it out.
Here is an article of why an open (recursive for all) is bad.
New 2009-08-18 : You can now give an asnumber (ex AS3292) and OpenDNS will show open DNS-servers in each of the IP-blocks in the AS.
This service is developed by DnsDigger
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