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Networking: A Beginner's Guide
I
f network wiring constitutes the nervous system of a network, then the devices
discussed in this chapter represent the various organs. These network devices--
repeaters, routers, hubs, and such--are responsible for moving data from one
network cable to another. Each device has different properties and uses. A good network
design uses the correct device for each of the various jobs the network must fulfill.
In this chapter, you learn about essential networking hardware, including the
following:
Repeaters
Hubs and concentrators
Switches
Bridges
Routers
Gateways
Firewalls
Short-haul modems for short interbuilding connections
It is essential that you understand these basic components that go into building a
network, as well as the job each performs.
Directing Network Traffic
The critical test of any network design is its capability to direct network traffic from
one node to another node. You must connect the network's various devices in a
configuration that enables the network to pass signals among the devices as efficiently
as possible, taking into account the type of network and the different connectivity
requirements for the network. The following are the basic connection devices:
Repeaters
These extend the distance that network traffic can travel over a
particular type of network media.
Hubs (concentrators)
These devices are used to connect nodes to one
another when you use a star topology, such as 100Base-T.
Bridges
These are basically intelligent repeaters that direct traffic from one
segment to another only when the traffic is destined for the other segment.
Routers
These can intelligently route network traffic in a variety of important
ways.
Switches
These form fast point-to-point connections for all the devices
connected to them. Connections from one port on a switch to another port are
made on an as-needed basis and are not broadcast to ports that aren't involved
in the traffic. By limiting the connections made, switches help eliminate traffic
collisions caused by noncommunicating segments.