User guide

Introduction to Network Security
2 WatchGuard Firebox X Edge
About Networks
A network is a group of computers and other devices that are con-
nected to each other. It can be two computers that you connect by a
serial cable or many computers connected by data communication
links located around the world.
A
Local Area Network (LAN) is a group of computers connected to
make a common work environment. This makes it easy to share
applications and data, and is important when a group of people
must do work together on one project.
A
Wide Area Network (WAN) is a group of computers that can be far
apart in different locations.
Clients and servers
The computer industry uses the words client and server for comput-
ers that are components of a network. A
server is a computer that
makes its resources available to the network and obeys the com-
mands of a client. Examples of server shared resources are files (a file
server), printers (a print server), and processing power (an applica-
tion server). A
client is a computer that uses the resources made
available by the server.
Connecting to the Internet
You have some options when you connect to the Internet. High-
speed Internet connections, including cable modem and Digital
Subscriber Line (DSL), are
broadband connections . Bandwidth is the
relative speed of an Internet connection, for example 1 Megabit per
second (Mbps).
You can use a cable modem to connect to the Internet through the
cable TV network. The cable modem usually has an Ethernet LAN
connection to the computer, and its speed can be more than
5 Mbps.
Typical speeds are usually lower than the maximum because cable
providers turn full neighborhoods into LANs that use the same
bandwidth. Because of this “shared-medium” topology, cable
modem users could have slower network access during times of peak
demand and can be more vulnerable to some attacks than users with
other types of connectivity.