Network tap  From Wikipedia, the free encyclopedia Jump to:
navigation, search  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 tap" may be the best way to accomplish this monitoring.
The network tap has (at least) three ports: an A port, a B port,
and a monitor port. A tap inserted between A and B passes all
traffic through unimpeded, but also copies that same data to its
monitor port, enabling a third party to listen.  Network taps
are commonly used for network intrusion detection systems, VoIP
recording, network probes, RMON probes, packet sniffers, and
other monitoring and collection devices and software that
require access to a network segment. Taps are used in security
applications because they are non-obtrusive, are not detectable
on the network (having no ph