A vampire tap is a device for physically connecting a station

Node (networking)

In communication networks, a node is a connection point, either a redistribution point or a communication endpoint . The definition of a node depends on the network and protocol layer referred to...

 (i.e. a PC, a printer, or another device) to a network that uses 10BASE5

10BASE5

10BASE5 was the original commercially available variant of Ethernet.For its physical layer it used cable similar to RG-8/U coaxial cable but with extra braided shielding. This is a stiff, diameter cable with an impedance of 50 ohms , a solid center conductor, a foam insulating filler, a shielding...

 cabling. This device clamps onto and "bites" into the cable (hence the vampire

Vampire

Vampires are mythological or folkloric beings who subsist by feeding on the life essence of living creatures, regardless of whether they are undead or a living person...

 name), forcing a spike through a hole drilled through the outer shielding to contact the inner conductor while other spikes bite into the outer conductor. From the vampire tap, a short cable called an AUI (Attachment Unit Interface

Attachment Unit Interface

An Attachment Unit Interface is a 15 pin connection that provides a path between a node's Ethernet interface and the Medium Attachment Unit , sometimes known as a transceiver. It is the part of the IEEE Ethernet standard located between the Media Access Control , and the MAU...

) is connected directly from the tap to the network card in the PC. Vampire taps allow new connections to be made on a given physical cable while the cable is in use. This allows administrators to expand bus-topology network sections without interrupting communications.

Without a vampire tap, the cable has to be cut and connectors have to be attached to both ends.

Vampire taps may also be used for malicious purposes such as transparent network monitoring.

See also

• Network tap
  Network tap
  A network tap is a hardware device which provides a way to access the data flowing across a computer network. In many cases, it is desirable for a third party to monitor the traffic between two points in the network. If the network between points A and B consists of a physical cable, a "network...
  
  
• Insulation-displacement connector
  Insulation-displacement connector
  An Insulation-displacement connector, insulation-displacement technology/termination or insulation-piercing connector is an electrical connector designed to be connected to the conductor of an insulated wire or cable by a connection process which forces a selectively sharpened blade or blades...
  
  , another insulation-piercing system