Black Hole

What Does Black Hole Mean?

A black hole, in the context of computer networks, is a place where incoming packets are destroyed or discarded without informing the sender or recipient of their failed delivery.


Data packets are sent to a black hole when they are directed to an offline or disconnected router. When this happens, all packets forwarded to that router are discarded and lost. Routers are dumb and cannot transmit status notifications to the sender and are virtually invisible to the entire network.

Techopedia Explains Black Hole

A computer communication network is composed of many different networks. Each is managed by a router that enables the routing of communications toward or away from that domain. If a particular router goes offline, a condition is created in which all the packets directed toward that router (or the connecting network) are lost as soon as they reach the point in the network where that router is installed. This is known as a black hole in the computer network.

Black holes may occur due to other circumstances. For instance, when a host in unreachable due to its offline state, or a recipient address belongs to a bogus IP address, an unconfigured router cannot handle such packets. This also creates black holes, where data packets traveling toward them and traffic routed toward them are lost.


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Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.