tarpit

A tarpit (also known as Teergrube, the German word for tarpit (German pronunciation: [ˈteːɐ̯ˌɡʁuːbə])) is a service on a computer system (usually a server) that delays incoming connections for as long as possible. The technique was developed as a defense against a computer worm, and the idea is that network abuses such as spamming or broad scanning are less effective if they take too long. The name is analogous with a tar pit, in which animals can get bogged down and slowly sink under the surface.