About DNS Sinkholes

A DNS sinkhole — also known as a sinkhole server, Internet sinkhole, or Blackhole DNS — is a DNS server that gives out false information to prevent the use of the domain names it represents. DNS sinkholes are effective at detecting and blocking malicious traffic, and used to combat bots and other unwanted traffic.

SonicOS/X provides the ability to configure a sinkhole with black and white lists.