Page 422 - StudyBook.pdf

406 Chapter 6 • Infrastructure Security: Devices and Media

Figure 6.18 Star Topology

Hub

One downside to UTP cable is that it is vulnerable to electromagnetic interfer-
ence (EMI) and radio frequency interference (RFI).These types of interference are
caused by everything from microwaves to power cables.This is one reason that
UTP cable should never be run in the same area as electrical wiring. STP cable is
shielded to protect it from these forms of interference, but is more expensive and
not as easy to work with. In addition, both coax cabling and UTP/STP are vulner-
able to eavesdropping.The simple act of sending electricity down the wires in the
cables creates a pulse that can be monitored and translated into the actual data
using specialized devices.

EXAM WARNING
The Security+ exam expects you to be aware of EMI and RFI. You need
to be aware of the interference that can cause issues with various media
types. In addition, a small amount of RF leaks from UTP cables. This leak
allows for organizations with very sensitive detection equipment to pick
up on some of the electrical signals going through the cabling. While it
is highly unlikely that anyone with equipment at this level of sophistica-
tion will want to monitor your network, it is certainly something to be
aware of.

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