The Complete A+ Guide
to PC Repair 5/e
Chapter 13
Introduction to Networking
Addison Wesley
is an imprint of
© 2011 Pearson Addison-Wesley. All rights reserved.
Chapter Objectives
Differentiate between peer-to-peer and serverbased networks
Identify commonly used network topologies
Compare and contrast types of network cabling
Explain the differences between various network
access methods
Explain how Ethernet works
Identify OSI model layers and the network
devices that work at each layer
© 2011 Pearson Addison-Wesley. All rights reserved.
Chapter Objectives
Articulate commonly used network protocols
Define the purpose and identification of a MAC
address and an IP address
Apply IP addressing concepts
Define the purpose of DHCP and DNS
Configure a computer for network connectivity
Use common network troubleshooting tools
Access a network printer
Define common networking terms
© 2011 Pearson Addison-Wesley. All rights reserved.
Chapter Objectives
Identify and define the function of the basic parts
of a wireless network
Distinguish between ad hoc and infrastructure
wireless NICs
List the different types of wireless NICs
Explain the purpose of an SSID and channel ID
List the three non-overlapping channel IDs used
in wireless networks
Contrast dBd with dBi
© 2011 Pearson Addison-Wesley. All rights reserved.
Chapter Objectives
Define and explain how to perform a basic
wireless site survey
Compare and contrast the 802.11a, 802.11b,
802.11g, and 802.11n wireless standards
After completing this chapter you will be able to:
Explain the basic protocols used with email
Describe how to be a proactive technician
© 2011 Pearson Addison-Wesley. All rights reserved.
Networking Overview
• Many networks are found all around us.
- The network of roads and interstate
highways
- The telephone network
- The electrical network that provides
electricity to our homes
- The cellular network that allows cell phones to
connect to one another as well as connectivity
between cell phones and the wired telephone network
and the Internet
- Air traffic control network
- Our network of friends and family
© 2011 Pearson Addison-Wesley. All rights reserved.
Networking Overview
Network – Two or more devices capable of communicating
and sharing resources between them.
-Types of networks
1
PAN – Personal devices such as PDAs, keyboards, mice,
headsets, communicate in close proximity through a wired or
wireless network.
2
LAN – A group of devices sharing resources in a single area
such as a room or a building.
3
MAN – Connectivity of sites within a city.
4
WAN – Communication between LANs on a larger geographic
scale—the Internet is the largest.
© 2011 Pearson Addison-Wesley. All rights reserved.
Types of Local Area Networks
• There are two basic types of LANs, a serverbased network and a peer-to-peer network.
• Server-based network - Users login to a server,
that knows who is authorized to connect to the
LAN and what resources the user is authorized
to access.
• Usually found in businesses comprising of 10 or more
computers.
• Also known as a client/server network.
• Collectively, these servers and client computers are
part of one or more domains.
© 2011 Pearson Addison-Wesley. All rights reserved.
Server-Based Network
© 2011 Pearson Addison-Wesley. All rights reserved.
Types of Local Area Networks
• Peer-to-Peer Network - A type of LAN wherein
each computer user acts as a server.
- Each computer stores password and sharing
information for its own resources.
- Usually has fewer than 10 computers
- The more resources that are shared on peer-to-peer
network, the more passwords and more cumbersome
password management will be.
• Workgroup - A term given to a peer-to-peer
Windows network.
• A workgroup does not use a server to authenticate
users during the login process.
© 2011 Pearson Addison-Wesley. All rights reserved.
Peer-to-Peer Network
© 2011 Pearson Addison-Wesley. All rights reserved.
Ethernet LANs
Ethernet is the most common type of LAN
Ethernet adapters
are the most
common network
cards.
© 2011 Pearson Addison-Wesley. All rights reserved.
The RJ-45 jack is
the most common
type of Ethernet
port.
Network Topologies
Network topology is how the network is wired.
•
•
•
•
•
•
Star Topology
Extended Star Topology
Hierarchical Topology
Ring Topology
Bus Topology
Mesh Topology
© 2011 Pearson Addison-Wesley. All rights reserved.
Network Topologies
• Hub- A device used with the
universal serial bus or in a
star network topology that
allows multiple device
connections.
• A network hub cannot look at each data frame coming
through its ports like a switch does.
• Switch- In star networks, a Layer two central
controlling device.
• Looks like a hub
• Looks at each data frame as it comes through each
port.
© 2011 Pearson Addison-Wesley. All rights reserved.
Tech Tip – Ethernet LANs are
wired in a star
• The most common network topology used today
is the star topology because it is used with
Ethernet networks.
© 2011 Pearson Addison-Wesley. All rights reserved.
Network Topologies
Topology Description
Bus
Not common anymore; takes less cable (cheaper); but
with a break in the bus, the network is down.
Hierarchical A common design model for businesses with quite a
few computers.
Mesh
With a break in the cable, the network still works (very
fault tolerant), but it takes a lot of cabling. Expensive
and complex—hard to configure.
Ring
Each network device connects to two adjacent network
devices. It is easy to install, but requires expensive
parts. A ring topology is used with fiber.
© 2011 Pearson Addison-Wesley. All rights reserved.
Network Topologies
Topology
Description
Star
The easiest to install, is the most common
(because of it being used with Ethernet), and a
break in a workstation cable does not affect the
rest of the network. More cable is used in wiring a
star topology, but the type of cable used is
comparatively cheap star topologies are easy to
troubleshoot.
Extended Star
The Extended Star topology contains multiple hubs
or switches. If one hub or switch goes down, only
those devices connected to that hub or switch will
fail to work. A network cable will connect the
device to hub or switch.
© 2011 Pearson Addison-Wesley. All rights reserved.
Network Media Overview
- Networks require some type of medium to
transmit data.
- This medium is normally some type of cable or
air.
- The most common types of cable are twistedpair copper and fiber-optic, although some very
old networks used coax cable and video
networks use coax.
© 2011 Pearson Addison-Wesley. All rights reserved.
Unshielded Twisted-Pair
Medium
To
Transmit
Data
Copper
Conductor
Plastic
Encasement
© 2011 Pearson Addison-Wesley. All rights reserved.
Vinyl Insulator
Copper Media
Twisted-Pair Cable – Network cable of eight copper
wires twisted into four pairs. Comes shielded and
unshielded.
UTP (Unshielded Twisted-Pair) – Most common
network cable. Comes in different categories for different
uses.
STP (Shielded Twisted-Pair) – Network cable with
extra foil to prevent outside noise form interfering with
data on the cable.
Crosstalk – A type of EMI where signals from one wire
interfere with the data on an adjacent wire.
© 2011 Pearson Addison-Wesley. All rights reserved.
UTP Cable
Figure 13.6
© 2011 Pearson Addison-Wesley. All rights reserved.
Copper Media
Plenum cable - A type of cable that is treated
with fire retardant materials so it is less of a fire
risk.
PVC (polyvinyl chloride) – Cable that has a
plastic insulation or jacket that is cheaper and
easier to install than plenum cable.
It can have flame-retardant added.
© 2011 Pearson Addison-Wesley. All rights reserved.
UTP Wiring Standards
Figure 13.7
© 2011 Pearson Addison-Wesley. All rights reserved.
RJ-45 pin 1 Assignments
Figure 13.8
© 2011 Pearson Addison-Wesley. All rights reserved.
UTP Cable Categories
© 2011 Pearson Addison-Wesley. All rights reserved.
Coaxial Cable
Coaxial cable - Type of network cabling used in
video networks, older Ethernet networks, as well
as mainframe and minicomputer connections.
Has a copper core, surrounded by insulation and
shielding from EMI.
© 2011 Pearson Addison-Wesley. All rights reserved.
Coax Cable with Connector
Used in
Older
Ethernet
Networks
Center
Copper
Conductor
Used in
Home Video
Network
© 2011 Pearson Addison-Wesley. All rights reserved.
Figure 13.9
Insulation—
Copper
Braid
& Metallic
Foil
Fiber Media
• Fiber-optic cable is made of glass or a type of
plastic fiber and is used to carry light pulses.
• Fiber-optic cable can be used to connect a
workstation to another device, but in industry, the
most common use of fiber-optic cable is to connect
networks together forming the network backbone.
• Fiber-optic cabling has
many advantages
including security, long
distance transmission,
and bandwidth.
© 2011 Pearson Addison-Wesley. All rights reserved.
Fiber Media
• Single-mode- A type of fiber-optic cabling that
sends one light beam down the cable.
• Multi-mode- A type of fiber-optic cabling that
allows multiple light signals to be sent along the
same cable.
• Which fiber should I use?
– Multi-mode fiber is cheaper and more commonly used
than single-mode fiber and is good for shorter
distance applications; but single-mode fiber can
transmit a signal farther than multi-mode and
supports the highest bandwidth.
© 2011 Pearson Addison-Wesley. All rights reserved.
Fiber Connectors
© 2011 Pearson Addison-Wesley. All rights reserved.
Protecting Your Network and Cable
Investment
Professional cable management systems keep
cables organized.
A secure room or cabinet should be
used to store network devices.
If possible network cabling should be
installed in conduit or raceways.
© 2011 Pearson Addison-Wesley. All rights reserved.
Ethernet Issues and Concepts
• Half-duplex - A serial device setting that allows
either the sending or the receiving device to
send data, one device at a time.
- On a cable, half-duplex is the ability to transmit in
both directions but not at the same time.
• Full-duplex - A serial device setting that allows
the sending and receiving device to send data
simultaneously.
- On a cable, full-duplex is the ability to transmit data in
both directions simultaneously.
© 2011 Pearson Addison-Wesley. All rights reserved.
Ethernet Issues and Concepts
• Ethernet networks were originally designed for
half-duplex transmission on a 10Mbps bus
topology.
- The more workstations on the same network, the
more collisions occur and the more network slows
down.
- In addition, with half-duplex Ethernet, less than 50
percent of the 10Mbps available bandwidth could be
used because of the collisions and the time it takes
for a network frame to transmit across the wire.
© 2011 Pearson Addison-Wesley. All rights reserved.
Ethernet Issues and Concepts
• Full-duplex more than doubles the amount of throughput on
a network because of the lack of collisions and transmitting
both directions simultaneously.
• Full-duplex is used when a switch is used to connect
network devices together.
© 2011 Pearson Addison-Wesley. All rights reserved.
Tech Tip – Why a switch is better
than a hub
When a workstation sends data to a hub, the hub broadcasts
the data out all ports except for the port the data came in on.
A switch, on the other hand, keeps a table of addresses.
When a switch receives data, the switch looks up the
destination MAC address in the switch table and forwards
the data out the port for which it is destined. A switch looks
very similar to a hub and it is sometimes hard to distinguish
between the two.
© 2011 Pearson Addison-Wesley. All rights reserved.
Network Standards
IEEE committees create network stands
called the 802 standards.
© 2011 Pearson Addison-Wesley. All rights reserved.
OSI Model
• OSI Model (Open Systems Interconnect
Model) – A standard for information transfer
across a network by the ISO.
• The model has seven layers – each layer uses the
layer below it, and each layer provides some function
to the one above it.
© 2011 Pearson Addison-Wesley. All rights reserved.
OSI Model
• The model sets several guidelines or describes
− how the different transmission media are arranged
and interconnected
− how network devices that use different languages
communicate with one another
− how a network device goes about contacting another
network device
− how and when data gets transmitted across the
network
− how data is sent to the correct device
− how a receiving device knows if the network data was
received properly
© 2011 Pearson Addison-Wesley. All rights reserved.
OSI Model Layers
© 2011 Pearson Addison-Wesley. All rights reserved.
Encapsulated Data in the
OSI Model
•
•
•
•
•
Bits – encapsulated data found at Layer 1
Frame - encapsulated data found at Layer 2
Packet- encapsulated data found at Layer 3
Segment – encapsulated data found at Layer 4
Data – any encapsulated info at Layers 5 through 7
© 2011 Pearson Addison-Wesley. All rights reserved.
OSI Model Terms
• ISP (Internet service provider)- A vendor that
provides connection to the Internet.
• Authentication- The process of determining
that a network device or person has permission
to access a network.
 The OSI model is very confusing when you are
first learning about networking, but it is very
important. Understanding the model helps when
troubleshooting a network.
© 2011 Pearson Addison-Wesley. All rights reserved.
Tech Tip – OSI Mnemonic
• A mnemonic to help remember the OSI layers.
−
−
−
−
−
−
−
A
Person
Seldom
Takes
Naps
During
Parties
• For example, A in the phrase is to remind you of
the application layer.
• P in Person is to remind you of the presentation layer,
and so on.
© 2011 Pearson Addison-Wesley. All rights reserved.
The TCP/IP Model
• A network protocol is a data communication
language.
− A set of rules for communication between two end
devices
• A protocol suite is a group of protocols that are
designed to work together.
• TCP/IP (Transmission Control Protocol/
Internet Protocol) – the protocol suite used in
networks today.
− It is the most common network protocol and is
required when accessing the Internet.
© 2011 Pearson Addison-Wesley. All rights reserved.
TCP/IP Model
• The TCP/IP model consists of four layers.
• Application
TCP/IP
Model
• Transport
• Internet
• Network Access
© 2011 Pearson Addison-Wesley. All rights reserved.
The TCP/IP Model
• The TCP/IP protocol suite consists of many protocols
◘ TCP (Transmission Control Protocol)
◘
IP (Internet Protocol)
◘
DHCP (Dynamic Host Configuration
Protocol)
◘
FTP (File Transfer Protocol)
◘
HTTP (HyperText Transfer Protocol)
© 2011 Pearson Addison-Wesley. All rights reserved.
The TCP/IP Model Layers
TCP/IP-based application-layer
protocols format data specific for the
purpose. Is equivalent to the
application, presentation, and
session layers of the OSI model.
Protocols include HTTP, Telnet, DNS,
HTTPS, FTP, TFTP, TLS, SSL, POP,
SNMP, IMAP, NNTP, and SMTP.
Application
Sometimes called the internetwork
layer. IP is the most common Internet
layer protocol. IP adds a source and
destination IP address to uniquely
identify the source and destination
network devices.
Internet
Transport-layer protocols add port
numbers in the header so the
computer can identify which
application is sending the data. When
data returns, this port number allows
the computer to determine into which
window on the screen to place the
data. Protocols include TCP and UDP.
Transport
Network access
Called link layer in the original RFC. Defines
how to format the data for the type of
network being used. Defines the type of
connector used and puts the data onto the
network, whether it be voltage levels for 1s
and 0s on the copper cable or pulses of light
for fiber.
The TCP/IP model is a real model. The OSI
model is theoretical.
© 2011 Pearson Addison-Wesley. All rights reserved.
The TCP/IP Model Layers
© 2011 Pearson Addison-Wesley. All rights reserved.
Tech Tip – Use netstat to view
current connections
• To see current
connections and
associated port numbers,
bring up a command
prompt and type netstat.
© 2011 Pearson Addison-Wesley. All rights reserved.
Networking Addressing
Ethernet network adapters normally have two
types of addresses assigned to them – a MAC
address and an IP address.
MAC address (media access control address)
– One of two types of addresses assigned to
network adapters, used when two devices on the
same network communicate.
Known as a Layer two address.
© 2011 Pearson Addison-Wesley. All rights reserved.
MAC Address
◘ Network adapter has this address burned
into a ROM chip
◘
Also known as a Layer 2 address
◘
48-bit address shown in hexadecimal
© 2011 Pearson Addison-Wesley. All rights reserved.
IP Address
© 2011 Pearson Addison-Wesley. All rights reserved.
IP Addressing Basic Terms
An IP address is broken into two major parts:
the network number and the host number.
Network NumberPortion of an IP
address that
represents which
network the
computer is on.
© 2011 Pearson Addison-Wesley. All rights reserved.
Host – A network
device. It also
represents the part
of an IP address
that identifies a
unique network
device.
Network Address
© 2011 Pearson Addison-Wesley. All rights reserved.
IP Addressing (network and host portions)
• Class A IP address –
0-127 in the first octet.
• Only the first octet is
the network part.
© 2011 Pearson Addison-Wesley. All rights reserved.
• Class B IP address –
128-191 in the first
octet.
• The first two octets are
the network part.
Figure 13.18
• Class C IP address –
192-223 in the first
octet.
• The first three octets
are the network part.
IP Addressing Terms
Broadcast Address
An IPv4 address used to communicate with all
devices on a specific network.
Subnet Mask
A number the computer uses to determine which
part of an IP address represents the network and
which portion represents the host.
© 2011 Pearson Addison-Wesley. All rights reserved.
IP Addressing (two network example)
© 2011 Pearson Addison-Wesley. All rights reserved.
Subnetting Basics
• In business, the subnet mask used does not
usually correspond to the class of IP address
being used.
• For example, at the college, the IP address
10.104.10.88 and subnet mask 255.255.255.0
are assigned to a computer.
− The 10 in the first octet shows that this is a class An IP
address with a default mask of 255.0.0.0.
− The 255 in the subnet mask is made up of eight 1s in
binary in the first octet (11111111) followed by all 0s in
the remaining octets (00000000.00000000.00000000).
© 2011 Pearson Addison-Wesley. All rights reserved.
Important Rules in Subnetting
The network number cannot be assigned to any
device on the network.
The network number contains all 0s in the host
portion of the address.
Note that this does not mean that the number will be 0 in
decimal. This is explained next.
The broadcast address (the number used to send a
message to all devices on the network) cannot be
assigned to any device on the network.
The broadcast address contains all 1s in the host
portion of the address.
Note that this does not mean that the number will be 255 in
decimal.
© 2011 Pearson Addison-Wesley. All rights reserved.
Tech Tip-Mask in prefix notation
Subnet masks in network documentation are
commonly shown in prefix notation, using a
slash with the number of consecutive 1s found
in the subnet mask. For example,
10.104.10.88 255.255.255.0 is shown as
10.104.10.88/24 and 192.168.10.213/27 is the
same as a 255.255.255.224 subnet mask.
© 2011 Pearson Addison-Wesley. All rights reserved.
Network Connection Types
© 2011 Pearson Addison-Wesley. All rights reserved.
DUN (Dial-Up-Networking)
• DUN is used when a remote computer that dials
into the Internet or into a company network
device uses a modem.
• The type of connection, protocol, and settings
that you configure on the remote computer
depends on the company to which you are
connecting.
• A connection protocol used with dial-up
networking is PPP.
• PPP (Point-to-Point Protocol) is connection-oriented,
layer two protocol that encapsulates data for
transmission over various connection types.
© 2011 Pearson Addison-Wesley. All rights reserved.
Wireless Network Overview
• Wireless networks are networks that transmit
data over air using either infrared or radio
frequencies.
• Most wireless networks in home and businesses use
radio frequencies.
• Wireless networks normally operate at layers one and
two of the OSI model.
• Wireless networks are very popular in home and
business computer environments and are great
in places that are not conducive to having
cabling, such as outdoor centers, convention
centers, bookstores, coffee shops and hotels.
© 2011 Pearson Addison-Wesley. All rights reserved.
Bluetooth
Bluetooth is a wireless technology for PANs
(personal area networks).
Bluetooth devices include PDAs (personal digital
assistants), audio/visual products, automotive
accessories, keyboards, mice, phones, printer
adapters, cameras, wireless cell
phone headset, sunglasses with a
radio and wireless speakers, and
other small wireless devices.
© 2011 Pearson Addison-Wesley. All rights reserved.
Bluetooth
Bluetooth works in the 2.4GHz range similar to
business wireless networks, has three classes of
devices (1, 2, and 3) that have a range of
approximately 6 meters (19.6 feet), 22 meters
(72.1 feet), and 100 meters (328 feet),
respectively, and a maximum transfer rate of
3Mbps.
Bluetooth supports both data and voice
transmissions.
© 2011 Pearson Addison-Wesley. All rights reserved.
Tech Tip-Missing Bluetooth
Control Panel
© 2011 Pearson Addison-Wesley. All rights reserved.
Bluetooth Troubleshooting
Batteries
If the Bluetooth device has batteries, ensure that
they are installed correctly and are functioning.
Move around
Change the location of the Bluetooth device – try
moving it closer to and further from the computer.
Watch out for 2.4Ghz
Ensure that no other devices that could interfere
in the 2.4GHz range are in the area.
Remove Bluetooth
Remove all other Bluetooth devices.
Remove USB
Remove any unused USB devices.
© 2011 Pearson Addison-Wesley. All rights reserved.
Bluetooth – More Troubleshooting
Transceiver used?
If a Bluetooth transceiver is used, move the
transceiver to another USB port.
Service started?
Use the Administrative Tools control
panel to access Computer Management
tool. Select Services and Applications in
the list on the left. Click Services in the
right panel. Locate and double-click
Bluetooth Support Service. Ensure that
the service is set to automatic and is
started.
© 2011 Pearson Addison-Wesley. All rights reserved.
Wireless Network Types
• There are two main types of wireless networks:
ad hoc and infrastructure.
Ad hoc
Used in wireless
networks where no
access point is used.
Instead, wireless devices
connect to one another.
© 2011 Pearson Addison-Wesley. All rights reserved.
Infrastructure
A type of wireless
network that contains an
access point for wireless
devices to be connected
together.
Wireless NICs
• Wireless NICs communicate with an
access point in infrastructure mode.
• Wireless NICs can be connected in many
ways.
PC
Card
USB
© 2011 Pearson Addison-Wesley. All rights reserved.
PCI
PCIe
Wireless Network Terms
Access
point
SSID
(Service
Set
Identifier)
A component of a wireless
network that accepts
associations from wireless
network cards.
A set of up to 32 alphanumeric
characters used in wireless
networks to differentiate between
different networks.
© 2011 Pearson Addison-Wesley. All rights reserved.
Tech Tip – Channel must match
Frequency
The channel ID (frequency) must be the
same between the access point and the
wireless NIC for communication to occur
between any wireless devices on the
same wireless network.
© 2011 Pearson Addison-Wesley. All rights reserved.
Non-overlapping Channels
© 2011 Pearson Addison-Wesley. All rights reserved.
Antenna Basics
• An antenna is used to radiate or receive radio waves.
• Two major categories of antennas
– Omnidirectional – Radiates energy in all directions
– Directional – Radiates energy in a specific direction
© 2011 Pearson Addison-Wesley. All rights reserved.
Antenna Basics
• Attenuation – The amount of signal loss of a
radio wave as it travels through the air.
• Antenna gain is measure in dBi, which is a
measurement of decibels in relationship to an
isotropic antenna. (The “i” is for isotropic).
• Some antennas are shown with a measurement of
dBd instead of dBi. This measurement is referenced
to a dipole antenna. (the “d” at the end is for dipole).
• Site Survey – Used in wireless networks design
to determine the best wireless hardware
placement for the optimum coverage area.
© 2011 Pearson Addison-Wesley. All rights reserved.
Wireless Network Standards
• The IEEE 802.11 committees define standards
for wireless networks and these can be quite
confusing.
• 802.11-based wireless networks use CSMA/CA
as an access method.
- Network devices listen on the cable for conflicting
traffic.
- The workstation then waits a small amount of time for
all other workstations to hear the jam signal, and then
the workstation begins transmission.
© 2011 Pearson Addison-Wesley. All rights reserved.
IEEE 802.11 Standards
© 2011 Pearson Addison-Wesley. All rights reserved.
Wired or Wireless NIC Installation
1
Determine that an appropriate slot, port, or
integrated wireless NIC is available.
2
In a corporate environment, the computer must
have a unique name.
3
Obtain and install the appropriate NIC driver.
4
Configure TCP/IP parameters.
© 2011 Pearson Addison-Wesley. All rights reserved.
TCP/IP Configuration
• DHCP (Dynamic Host Configuration Protocol)
– A method to automatically assign IP addresses
to network devices from a pool of IP addresses.
• Default Gateway - The IP address of the Layer
three device, such as a router, that is directly
connected to its immediate network.
• It tells a device on its network where to send a packet
destined for a remote network.
© 2011 Pearson Addison-Wesley. All rights reserved.
Tech Tip-How to assign a default
gateway
© 2011 Pearson Addison-Wesley. All rights reserved.
Network Terms
DNS
Domain Name System server – translates
Internet names into IP addresses
URL
Uniform Resource Locator – A method of
accessing Internet resources
WINS
Windows Internet Naming Service server – Keeps
track of IP addresses assigned to a specific
computer name.
© 2011 Pearson Addison-Wesley. All rights reserved.
Default Gateway
Figure 13.41
© 2011 Pearson Addison-Wesley. All rights reserved.
Tech Tip-Newer DNS servers
provide name resolution
© 2011 Pearson Addison-Wesley. All rights reserved.
Access Point/Router Installation
• Many wireless access points have the ability to
route.
• The router connects
the wired network
and the wireless network
together. A router is
also good to have so
that DHCP can be
provided for both the
wired and the wireless
networks and to provide
a firewall for network security.
© 2011 Pearson Addison-Wesley. All rights reserved.
Access Point/Router Installation
• The following list helps with access point
installation:
- What is the SSID to be used?
- Is WEP, WPA, WPA-PSK, WPA2-PSK, TKIP,
AES, or any other security option enabled?*
- What security key lengths, security keys, or
passphrases are used?*
- Is MAC address filtering enabled?*
- Is there power available for the access point?
*Note that these options are discussed in Chapter 14.
© 2011 Pearson Addison-Wesley. All rights reserved.
Access Point/Router Installation
• The following list helps with access point
installation:
- How will the access point be mounted?
- Where should the access point be mounted
for best coverage of the wireless network
area?
- What channel ID will be used?
- Will the access point connect to the wired
network, if so, is there connectivity available
where the access point will be mounted?
© 2011 Pearson Addison-Wesley. All rights reserved.
Configuring a Networked Printer
• There are three ways to network a printer
1
Connect a printer to a port on a computer that is
connected to the network and share the printer.
2
Setup a computer or device that is designated as a
print server. Connect the print server to the network.
3
Connect a printer with a network connector installed
directly on the network.
© 2011 Pearson Addison-Wesley. All rights reserved.
Network Troubleshooting
• One way to troubleshoot a network is to
determine how many devices are affected.
• The ping command can be used to check
connectivity all around the network.
- Ping - A network troubleshooting command used to
test TCP/IP communications and determine if a
network path is available, whether any delays exist
along the path, and if a remote network device is
reachable.
- Use ping with the private IP address 127.0.0.1 to test
a NIC’s basic network setup.
© 2011 Pearson Addison-Wesley. All rights reserved.
Network Troubleshooting
ipconfig
Command to view the current IP
settings
nslookup
Command that displays network
domain names and associated IP
addresses
tracert
Command that displays the path a
packet takes through a network (to
see where a fault occurs)
latency
Delay experienced as packets travel
from source to destination. Use ping
and tracert to view.
© 2011 Pearson Addison-Wesley. All rights reserved.
Sample Network Troubleshooting Scenario
Figure 13.47
© 2011 Pearson Addison-Wesley. All rights reserved.
IPCONFIG and IPCONFIG/ALL
Figure 13.48
© 2011 Pearson Addison-Wesley. All rights reserved.
Network Troubleshooting
• The following list contains methods that can help
with NIC troubleshooting:
- From a command prompt window, ping
127.0.0.1 to test the NIC.
- Ping another device on the same network.
- Ping the default gateway.
- Ping a device on a remote network.
- Use the tracert command to see if the fault is
inside or outside the company.
© 2011 Pearson Addison-Wesley. All rights reserved.
Networking Troubleshooting
• The following list contains methods that can help
with NIC troubleshooting:
- Check the status light on the NIC to see if the physical
connection is good.
- Check the status light on the hub or switch that is
used to connect the workstation NICV to the network.
- Check cabling.
- Update the device driver by obtaining a newer one
from the NIC manufacturer Web site.
- Check the IP addressing used.
- If on a laptop, ensure that the wireless NIV is
enabled.
© 2011 Pearson Addison-Wesley. All rights reserved.
Network Terminology
In the networking field, there are many acronyms
and terms with which you must be familiar.
Backbone - The part of the network that connects
multiple buildings, floors, networks, and so on
together.
Bandwidth – The width of communications channel
that defines its capacity for data.
Baseband – The entire cable bandwidth is used to
transmit a digital signal.
Broadband – Cable bandwidth is divided into multiple
channels.
© 2011 Pearson Addison-Wesley. All rights reserved.
Network Terminology
CDMA (Code Division Multiple Access) – A
protocol used in cellular networks as an
alternative to GSM.
FastEthernet – An extension of the original
Ethernet standard that permits data transmission
of 100Mbps.
FDDI (Fiber Distributed Data Interface) - A
high-speed fiber network that uses the ring
topology and the token passing method of
access.
© 2011 Pearson Addison-Wesley. All rights reserved.
Network Terminology
FTP (File Transfer Protocol) – A protocol used
when transferring files from one computer to
another across a network.
GMS (Global System Mobile) – The most
widely used digital technology for cellular
networks.
HTML (Hypertext Markup Language) – The
programming language used on the Internet for
creating Web pages.
HTTP (Hypertext Transfer Protocol) – A
protocol used when communicating across the
Internet.
© 2011 Pearson Addison-Wesley. All rights reserved.
Network Terminology
HTTPS (Hypertext Transfer Protocol over
Secure Socket Layer or HTTP over SSL) –
Encrypted HTTP communication through an SSL
session.
Infrared – A few laptop computers have infrared
ports that allow them to communicate with other
devices (such as another computer or printer)
across a wireless network.
LPR (Line Printer Remote) – A protocol used to
send print jobs to non-Windows clients.
© 2011 Pearson Addison-Wesley. All rights reserved.
Network Terminology
NAT/PAT (Network Address Translation/Port
Address Translation) – A method of conserving
IP addresses.
NAT uses private IP addresses that become
translated to public IP addresses.
PAT does the same thing except uses fewer public IP
addresses by “overloading” one or more public IP
addresses by tracking port numbers.
POP (Point of Presence)- A POP is an Internet
access point.
© 2011 Pearson Addison-Wesley. All rights reserved.
Network Terminology
POP (Post Office Protocol) – POP is used to
retrieve email from a network server.
SNMP (Simple Network Management
Protocol) - A protocol that supports network
monitoring and management.
SSH (Secure Shell) – A protocol used to
exchange data securely between two network
device.
SSL (Secure Sockets Layer) – A protocol used
to transmit Internet messages securely.
© 2011 Pearson Addison-Wesley. All rights reserved.
Network Terminology
TCP (Transmission Control Protocol) – A
layer four connection-oriented protocol that
ensures reliable communication between two
devices.
Telnet – An unsecure application that allows
connection to a remote network device.
UDP (User Datagram Protocol)- A layer four
connectionless protocol that applications use to
communicate with a remote device.
© 2011 Pearson Addison-Wesley. All rights reserved.
Network Terminology
VoIP (Voice over IP) – Sending a phone
conversation over a TCP/IP-based network
instead of traditional telephone circuits and
wiring.
© 2011 Pearson Addison-Wesley. All rights reserved.
Sharing
Network share – A folder or network device that
has been shared and is accessible from a
remote computer.
UNC (universal naming convention) – Used at
the command prompt to obtain network shares.
\\Cschmidt\tests - Goes to a computer named
Cschmidt and accesses a share names “tests.”
A teacher computer called ATC-227-01 has a share
called NetFundamentals. To access the files on this
computer, from a command prompt, the Run utility, or
the Search programs and files textbox, type the
following: \\ATC-227-01\NetFundamentals.
© 2011 Pearson Addison-Wesley. All rights reserved.
Email
Another common Internet software application is
an email (electronic mail) package to send
messages across the Internet.
When you send an email to someone, your
email client software formats the message and
sends it to an email server.
© 2011 Pearson Addison-Wesley. All rights reserved.
Email
The email server has the following functions:
Has a database of email accounts
Stores messages (email) sent and received
Communicates with other email servers
Uses the DNS protocol to locate the other
servers
© 2011 Pearson Addison-Wesley. All rights reserved.
Email
SMTP (simple network management
protocol) - A standard used for email or for
transferring messages across a network from
one device to another.
POP3 (soon to be POP4) – Post Office Protocol
or Point of Presence. Post Office Protocol is
used to retrieve email form a mail server. Point
of Presence is an Internet access point.
© 2011 Pearson Addison-Wesley. All rights reserved.
Email
IMAP (Internet Mail Access Protocol) – Used
to receive email through the Internet.
MAPI (Messaging Application Programming
Interface) – A Microsoft-proprietary protocol
used with email.
© 2011 Pearson Addison-Wesley. All rights reserved.
Tech Tip-Forwarding Email
To configure a particular application such as Google Gmail
to be forwarded to another application such as Outlook, key
information must be gathered.
1
2
the supported list of protocols used to send and
receive email such as IMAP, SMTP, POP, and SSL
the particular port numbers used with the
previously obtained supported protocols
The technician must then go into the email application and
configure an incoming mail server and an outgoing mail
server settings, based on the gathered information.
© 2011 Pearson Addison-Wesley. All rights reserved.
Soft Skills – Being Proactive
A good technician is proactive, which
means that the technician thinks of ways to
improve a situation or anticipates problems
and fixes them before being told to do a
particular task.
A proactive technician follows up after a
service call to ensure that a repair fixed the
problem rather than waits for another help
desk ticket that states that the problem is
unresolved.
© 2011 Pearson Addison-Wesley. All rights reserved.
Questions???
Addison Wesley
is an imprint of
© 2011 Pearson Addison-Wesley. All rights reserved.