A “Black Hole” can be defined many ways. One definition is “An area of space-time with a gravitational field so intense that its escape velocity is equal to or exceeds the speed of light”, another is “A great void or abyss”, and yet another and more relevant definition is “What data has fallen into if it disappears mysteriously between its origin and destination sites” For instance, an e-mail that never reaches it’s destination and the sender never receives a bounce or undeliverable message.
Darknet's - The Internet – A Million Points Of Light
Just for a moment, try to visualize the Internet like a clear night sky with millions of stars. Some stars are dim while others are bright, and others appears to blink on an off. Now turn your attention to what you “don’t” see. What appears to be the black spaces between stars in the night sky. In many cases, there are stars there, just to faint to see with the naked eye. However, great voids of darkness could be the result of a black hole, an area of space where nothing that goes in, not even light, can escape.
There are places like this on the Internet. Some are there by accident, maybe through the incorrect configuration of a router or group of Internet hosts. But there are those areas of Internet dark space that are there quite on purpose. Darknet’s, unlike honey nets or honey pots, where malicious activity can be monitored and recorded, appear as black holes in the Internet address space. Any data, communications, or request that falls into a Darknet is lost for ever. The sending host never receives a response.
A Darknet, intentionally configured, is a great research and monitoring tool. In many cases, these systems are used as early warning systems. For instance, say a new worm appears and starts probing the Internet address space for live hosts to infect. Many worms do so in a blind fashion, scanning and probing many areas of address space on the Internet. Because Darknet’s are relatively quite areas of the Internet, any spike in incoming activity may be considered suspicious. As the packets of data stream into the Darknet, they are collected and can then be analyzed. Because the host the packet originated from never receives a response, it may continue to stream its data into the Darknet hoping to finally find a live host. Unfortunately for the sending host, it never will.
Conclusion
If you are interested in learning more about Darknet’s, maybe even setting one up your self, take a look at the work done by Team Cyrmru. They have posted detailed information on how to construct a Darknet and provide statistical information on their Darknet servers and other Internet network monitoring initiatives