Tecnologia

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CompTIA Network+ Certification
®

™

2009 Edition
LAN

B

Segment 1

Ne t wor k+ C er t if iC at ioN

Segment 2

C
Backbone

Node

D

Node

Node

Node Host

Bus

Router

e

Ring

Node

Node

Host

Node

f

Router

Star

MSAU

E

a

What’s New?

IP addresses (version 6)

IPv6 addresses are 128 bits. Thereare five types of IPv6
addresses: link-local, site-local, global unicast, multicast, and
anycast. See page 3.

G

M
PL

Wireless network protocols

Mesh

H

Hybrid: Combined bus and star

Wireless networks send and receive information by using one
of four major wireless protocols: Wi-Fi (Wireless Fidelity),
Bluetooth, 802.11a, or WiMAX (IEEE 802.16 Air Interface
Standard). Seepage 4.

Security practices and devices

Use firewalls, security zones, and intrusion detection or
prevention systems. Modify the default configuration of your
operating system or network operating system to make it more
secure from outside threats. See page 4.

Network-to-network connections

a

LAN (local area network)

A LAN is a specifically designed configuration of computersand other devices that are
located within a confined area and connected by wires or radio waves that permit the
devices to communicate with one another to share data and services.

y

Node — A device with an address that can be accessed to send or receive
information.

y

Host — A computer with an operating system that manages its applications, its
hardware, its network connection, andthe resources that are shared on the network.

Large networks are frequently made up of segments and backbones.

y

Segment — The portion of the network on either side of two network transmission
devices. These devices include routers, bridges, repeaters, switches, and hubs.

C

y

Backbone — A high-speed network link connecting segments. Backbones are used in
large buildings or innetworks that span more than one building.

SA

B

Topologies

D

y

Bus — All nodes are connected to a main communication line (bus)—typically
a coaxial cable that is terminated at both ends. Transmissions from the nodes
propagate the length of the medium and are received by all other nodes. In a bus
topology, a malfunctioning node doesn’t disrupt the entire network. However, abreak
in the bus will disconnect hosts from each other.

e

y

Ring — Nodes are arranged in a closed loop, with each node connected to a central
device by two wires. The central device is called a multistation access unit (MSAU).
Communication is enabled by passing a token around the ring; if a node has the
token, it can transmit data. Repeaters at each node connection minimize signaldegradation. Adding new nodes can be difficult, however, due to the closed ring.

f

G

H

y

y
y

Star — Nodes are connected via point-to-point links to a central location (a hub
or switch). This topology minimizes failure from an individual segment break and
simplifies the adding or moving of nodes. One disadvantage: If the central node fails,
the whole network becomes disconnected.Mesh — All nodes in the mesh have independent connections to all other nodes in
the mesh. The mesh topology requires computers to have multiple network cards,
and due to its complexity, it’s rarely used.

Set up ISP connections to the Internet, and configure internal
network wiring for a large network. See page 5.

Security threats and attacks

Learn about security threats and attacks,and protect your
network from malicious software. See page 6.

Other Important Information

Cables, connectors, and Ethernet types
Identify common cables and connectors, and review the various
Ethernet architectures and designations. See page 2.

Network devices

Identify the functions of various network devices, such as
repeaters, bridges, routers, and gateways. See page 5.

TCP/IP...