Several DNS servers provide filtering against different categories, mostly for the local government 'undesirable content', some for malware, and some for ads. What I want is to create/use a DNS server that compare against those filtering DNS servers and only provide the address if all the DNS server agrees. For example if DNS server G provide a clean, unfiltered result, DNS server N provide malware and/or pornography filter, and DNS server F provide ad filter, then G, N and F will only provide the same/similar answer if the query is not categorized as malware, pornography, or advertising. Thus, by creating a server M that only answer if all DNS server agree, M effectively filter against all those categories. Maybe it's possible to do this on DDWRT or Tomato, but if not, I would settle for a solution that can be run in Linux/Windows.