NR-1 Sinkhole NR-1 Sinkhole The NR-1 Sinkhole is a giant underwater sinkhole located in the Straits of Florida southwest of Key West, Florida. It is found at an approximate depth of of water at the foot of the Pourtales Escarpment, an area of Quaternary sediment. It was discovered in October 1994 during a survey conducted by the American submarine NR-1, a U.S. Navy nuclear research submarine, and is named for the submarine. It was first identified via side-scan sonar and near-bottom echo sounder data, prompting a second survey in May 1995 to confirm the finding. Discovery of the NR-1 Sinkhole prompted scientific
DNS sinkhole in a DoS attack. One use is to stop botnets, by interrupting the DNS names the botnet is programmed to use for coordination. The most common use of a hosts file-based sinkhole is to block ad serving sites. Ad serving can also be blocked using a locally running DNS server on your computer or on your local network effectively blocking Ads for all devices on the network. DNS sinkhole 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 a domain name.