A:Some fast (and useful) DNS resolvers are only accessible to some users on the Internet. An example might be those belonging to specific ISPs who have configured their resolvers for access only by their own customers. But during testing, we also discovered that some fast and useful resolvers were accessible to many users, but not others. Rather than exclude some potentially fast resolvers from the list, we decided to provide any that might be worthwhile, and allow the DNS Benchmark to determine whether they were accessible. Leaving the red marked resolvers in the Benchmark's list does not slow down the benchmarking, and they can be easily removed by right-clicking the mouse on the list and choosing "Remove dead nameservers."

A:The DNS Benchmark colors working DNS resolvers orange when they do not return DNS errors in response to non-existent domain names. Instead, they return the IP address of a web “intercept page” that some ISPs and third-party DNS providers use to generate advertising and marketing revenue from their users' domain name “typos.” You can give the resolver a try by configuring your system to only use orange DNS resolvers, then deliberately mistype a domain name in your web browser and see how you feel about whatever it is that happens.

Note also that this behavior has raised enough stir among annoyed users that IPSs and third-party providers who are doing this often provide some means for turning off this behavior for individual customers. So if you would like to use “orange” resolvers, you might see whether there's a means for deactivating this behavior at the provider's end.