Page 816 - (ISC)² CISSP Certified Information Systems Security Professional Official Study Guide

Strong familiarity with these secure network components can assist

you in designing an IT infrastructure that avoids single points of
failure and provides strong support for availability.

Collisions vs. Broadcasts

A collision occurs when two systems transmit data at the same
time onto a connection medium that supports only a single
transmission path. A broadcast occurs when a single system

transmits data to all possible recipients. Generally, collisions are
something to avoid and prevent, while broadcasts have useful
purposes from time to time. The management of collisions and
broadcasts introduces a new term known as domains.

A collision domain is a group of networked systems that could
cause a collision if any two (or more) of the systems in that group
transmitted simultaneously. Any system outside the collision

domain cannot cause a collision with any member of that collision
domain.

A broadcast domain is a group of networked systems in which all
other members receive a broadcast signal when one of the
members of the group transmits it. Any system outside a broadcast
domain would not receive a broadcast from that broadcast domain.

As you design and deploy a network, you should consider how
collision domains and broadcast domains will be managed.

Collision domains are divided by using any layer 2 or higher
device, and broadcast domains are divided by using any layer 3 or
higher device. When a domain is divided, it means that systems on
opposite sides of the deployed device are members of different
domains.

These are some of the hardware devices in a network:

Repeaters, Concentrators, and Amplifiers Repeaters,
concentrators, and amplifiers are used to strengthen the

communication signal over a cable segment as well as connect network
segments that use the same protocol. These devices can be used to