Sinkhole Sinkhole A sinkhole, also known as a cenote, sink, sink-hole, swallet, swallow hole, or doline (the different terms for sinkholes are often used interchangeably), is a depression or hole in the ground caused by some form of collapse of the surface layer. Most are caused by karst processes—for example, the chemical dissolution of carbonate rocks or suffosion processes. Sinkholes vary in size from both in diameter and depth, and vary in form from soil-lined bowls to bedrock-edged chasms. Sinkholes may form gradually or suddenly, and are found worldwide. Sinkholes may capture surface drainage from running or standing water, but may
DNS sinkhole to a higher-level provider to try again. The higher a DNS Sinkhole is in this chain, the more requests it will receive, and the more impactful it will be. A sinkhole is a standard DNS server that has been configured to hand out non-routable addresses for all domains in the sinkhole, so that every computer that uses it will fail to get access to the real website. The higher up the DNS resolution chain the sinkhole is, the more requests it will block as it will supply answers to a greater number of lower NS servers that in turn will