Lesson 1
Lesson 1
Understanding Local Area Networking
Learning Objectives
Students will learn to:
 Examine Local Area Networks, Devices, and Data Transfer
 Identify Network Topologies and Standards
ODN Skills


Understand local area networks (LANs).
Understand network topologies and access methods.
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1.5
Lesson Summary — Lecture Notes
You should begin this lesson by introducing yourself and the course.
The rest of the lesson is an introducing to networking. Therefore, you should start with
explaining what a network is and then explain what a LAN is and give some examples of
LANs. Most LANs are within a building or set of buildings that are all close together.
You can then describe that, in order to make up a network, you must have something to
share and a method to share that data (such as a network and a protocol or protocols to
share the data).
You can then describe a home network (a very simple and very small network) and a
large company network. As some networks are large and complex, and network engineers
and administrators come and go, administrators may not always be available when a
problem occurs. An administrator may forget about a setting, a configuration, or a
solution to a problem, so network documentation is extremely important. To help create
some of the documentation, Microsoft Visio comes in handy when creating diagrams.
The next part of the lesson starts describing a simple LAN consisting of a hub. You could
mention that hubs are legacy devices but it is still a good place to start so that students
can understand how hubs and switches function. Of course, in the example, you have a
server providing a service and the PC, Mac and laptop requesting services from the
server.
After they understand a simple LAN, you can then explain what a SOHO is (as shown in
in Figure 1-2). A SOHO may be a small satellite office or even a simple home office.
Rather than have dedicated servers and expensive routers, you would use an inexpensive
router, which will allow you to share a DSL or cable modem connection to the Internet
among multiple users.
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Lesson 1
To create a network, a host will need to have a network adapter. Therefore, you would
explain what a network adapter is and then explain the different types of adapters. They
would differ by how they connect to the host and what connections and speeds they
support. You could then show how to install and configure a network adapter.
To add a host with a NIC to a wired network, you would then use a patch cable. If you
have one handy, you can show the students a patch cable. Be sure to mention that it is a
cable used for Ethernet networks and has RJ-45 connectors.
One of the common characteristics for network connections is network speed. Therefore,
that you can explain that most network cables use serial data transfers and that their
speeds are specified in megabits per second (or Mbps). This should not be confused with
Megabytes per second (MBps).
For a host to communicate on a network, it has to have a logical address. For a TCP/IP
network, the logical address is the IP address. You would then explain the four octets
ranging from 0 to 255 and how the subnet mask relates to the IP address. You could then
discuss classful networks consisting of Class A, B and C networks and their default
subnet masks.
To show the students an IP address in use, you will then show how to configure an IP
address in Windows and how it communicates with another computer by using the ping
command. Explain how the ping command is a very handy tool when testing network
connectivity and testing the sending’s host IP configuration (loopback/localhost).
Mention that the ping command uses the ICMP protocol.
Now that the students have an understanding of a wired network, explain that wireless
LANs are very common. Discuss the various devices that connect to a wireless network
(besides computers, phones and pads).
The next part of the lecture talks about how to protect your network by adding a network
into a perimeter network or DMZ. You can then discuss the different ways to form a
DMZ.
The next part of the lesson describes the network topology. Consider digging a bit deeper
by describing logical topology and physical topology. For example, today’s Ethernet
usually forms a physical star topology, but the signals still form a bus topology.
The most common type of network is an Ethernet network. Therefore, you can then cover
the different Ethernet standards. While it is okay for students to know the original
standards (such as 10Base 5 and 10Base2) in today’s world, they need to know today’s
popular standards (including 100Base-TX and 100Base-T).
The next part of the lesson discusses various models, including the client-server model
and peer-to-peer model. You will need compare and contrast these two models. You can
then cover different types of servers, including Windows, Linux and UNIX. You can then
cover the different versions of Windows servers and their related client operating system.
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Lesson 1
Key Terms
8P8C - A common connector or plug used on the end of the network cable. Also known
as RJ-45.
Broadcast – A method of communication where packets are sent to every host on the
network.
centralized computing – A model where all computing for a network is done by a large
central device.
client-server – A model that distributes applications between servers such as Windows
Server 2008 and client computers such as Windows 7 or Windows Vista machines.
CSMA/CA – Short for carrier sense multiple access with collision avoidance. It is used
as a method for multiple hosts to communicate on a wireless network and AppleTalk.
CSMA/CD – Short for carrier sense multiple access with collision detection. It is the
method for multiple hosts to communicate on a Ethernet.
computer telephony integration (CTI) - When a company’s telephone system meets its
computer system. Here, special PBXs that used to control phones as a separate entity can
now be controlled by servers with powerful software.
CTI-based server - When a company’s telephone system meets its computer system.
Here, special PBXs that used to control phones as a separate entity can now be controlled
by servers with powerful software.
data transfer rate – Network speed, also known as bit rate. This is defined as the
maximum bits per second (bps) that can be transmitted over a network.
database server - A server that provides data for applications.
demilitarized zone (DMZ) - Also known as a perimeter network, a small network that is
set up separately from a company’s private LAN and the Internet.
distributive computing – A model where computing is provided by each host.
Ethernet – A networking standard that has a set of rules that govern the transmission of
data between network adapters and various central connecting devices.
file server – A server that stores files for computers to share
frames – A group of bytes packaged by a network adapter for transmission across the
network.
full duplex – A type of communication where traffic is sent in both directions at the same
time.
half duplex – A type of communication where traffic is sent in both directions, but only
one at a time.
host – A device or computer has an IP address
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Lesson 1
hub - A basic central connecting devices (sometimes referred to as CCDs) that connects
each of the networked computers, known as hosts, to one another by way of copper-based
cables. A hub is considered a legacy device.
IEEE 802.3 – A standard that defines carrier sense multiple access with collision
detection or CSMA/CD. Because computers on a default Ethernet LAN all share the
same channel, CSMA/CD governs the way that computers co-exist with limited
collisions.
IP address – A logical address that identifies a device or host connected on a network.
local area network (LAN) – A group of these computers that are confined to a small
geographic area, usually one building.
medium dependent interface (MDI) – A port used to daisy chain or stack one or more
hubs or switches.
mesh topology – A topology where every host or server is connected to every other host
or server.
messaging server - Email servers, but also fax, instant messaging, collaborative, and
other types of messaging servers. For a Windows Server to control email, special
software known as Exchange Server has to be loaded in addition to the operating system.
Microsoft ISA Server – Microsoft’s firewall and proxy server.
Microsoft Visio - A common tool used for network documentation
multistation access unit (MAU) – A central connecting device usually associated with
Token Ring.
network adapter - Also known as a network interface card or NIC, it is the device that
enables you to send and receive data to and from your computer.
network controller – A controlling server such as a Microsoft domain controller, it is in
charge of user accounts, computer accounts, network time, and the general well-being of
an entire domain of computers and users.
network documentation - Any information that helps describe, define, and otherwise
explain how computers are connected in a physical and logical way.
network operating systems – An operating system used by a server to provide network
services.
network topology – A method that defines the physical connections of hosts in a
computer.
peer-to-peer (P2P) – A model that has each computer has an equal ability to serve data
and to access data, just like any other computer on the network.
perimeter network - Also known as a DMZ, a small network that is set up separately
from a company’s private LAN and the Internet.
print server - A server controls printers that can be connected directly to the server or
(and more commonly) are connected to the network.
ring topology – A topology that forms a ring or loop.
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Lesson 1
RJ45 – A common connector or plug used on the end of the network cable.
serial data transfer – A method where data is sent, one bit at a time.
star topology – A topology where each computer is individually wired to a central
connecting device with twisted-pair cabling.
switch – A device similar to a hub that connects computers to a central point. However,
different from a hub, a switch will only forward traffic to its destination instead of
broadcasting.
Transceiver – A device or component that can transmit and receive data.
unicast – A communication method where traffic is only sent to the computer or host that
is meant to be sent to.
virtual LAN (VLAN) – A group of hosts with a common set of requirements that
communicate as if they were connected together with a common set of requirements that
communicate as if they were connected together in a normal fashion on one switch,
regardless of their physical location.
web server – A server that share data and provide information about a company using
HTML web pages..
wireless access point (WAP) – A central connecting device used in wireless networks.
wireless LAN (WLAN) – A network that uses wireless signals.
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Lesson 1
Lesson 1
Server Overview
Knowledge Assessment
Multiple Choice
Circle the letter that corresponds to the best answer.
1.
2.
3.
4.
5.
Which of the following regenerates a signal and broadcasts that signal to
every computer connected to it?
a.
Hub
b.
Switch
c.
Router
d.
Firewall
Which of the following is not a central connecting device?
a.
Hub
b.
Switch
c.
SOHO router
d.
Windows 7 client
You need to install a network adapter to a computer so that it can be
connected to a network that uses twisted-pair cabling. What type of port
does the network adapter need to use?
a.
RJ11
b.
RJ45
c.
RG-58
d.
Fiber optic
Where can you go in Windows 7 to access the Properties of a network
adapter?
a.
Device Manager
b.
Ping
c.
Advanced Firewall
d.
Task Manager
You need to connect a computer’s network adapter to a switch. You want
the connection to be able to send and receive data simultaneously. What
type of connection do you need?
a.
Half duplex
b.
Full duplex
c.
Simplex
d.
100 Mbps
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Lesson 1
6.
7.
8.
9.
You need to connect a computer at a rate of 100,000,000 bits per second.
What speed network adapter should you install?
a.
10 Mbps
b.
100 MB/s
c.
100 Mbps
d.
1000 Mbps
You need to connect to a router that has the IP address 192.168.1.100 on a
standard, default Class C network using the subnet mask 255.255.255.0.
Which of the following is a valid IP address for your network adapter?
a.
192.168.0.1
b.
192.168.1.1
c.
192.168.100.1
d.
192.168.1.100
You have just installed a network adapter and configured an IP address and
subnet mask. What command can you use to verify that the IP address is
configured and listed properly?
a.
Ping
b.
Tracert
c.
CMD
d.
Ipconfig
You need to ping your own computer to see if it is alive. Which of the
following would qualify as command-line syntax to do so?
a.
ping localclient
b.
ping 128.0.0.1
c.
ping loopback
d.
ping network adapter
10. You have been instructed to connect a computer to a group of hosts that
have been segmented from the regular network. What kind of network is
this?
a.
LAN
b.
WLAN
c.
WAN
d.
VLAN
Fill in the Blank
Fill in the correct answer in the blank space provided.
1.
The manager of IT asks you to connect a perimeter network to the firewall,
which will be separate from the LAN. This type of network is known as a
DMZ
2.
A star topology can be defined by connecting several hubs to a switch.
3.
802.3u Ethernet networks run at 100 Mbps.
4.
A BitTorrent client is a program used to download files quickly from a
P2P network.
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Lesson 1
5.
The Token Ring network architecture is physically a star and logically a
ring.
6.
802.3ab Ethernet networks run at 1000 Mbps.
7.
A Half duplex connection is one in which data can be both sent and
received, but not at the same time.
8.
A ring topology can be defined as connecting several computers together in
a circle without the use of a hub or a switch.
9.
When several computers are connected in a small geographic area, it is
known as a local area network.
10. A wireless access point acts as a central connecting device and allows
laptops, PDAs, and handheld computers to communicate with each other.
Case Scenarios
Scenario 1-1: Planning and Documenting a Basic LAN
Proseware, Inc. requires you to implement a 20-computer LAN. Fifteen of these
computers will be Windows 7 clients and five will be Windows Server 2008 computers.
The company also requires a 24-port switch, router, DSL Internet connection, DMZ with
web server, and a laptop for the CEO. Create a diagram of the network documentation for
this in Microsoft Visio or on paper. Refer to Figures 1-1 through 1-3 for types of devices
in the Visio networking stencils.
Figure 1-23 shows an example of what this documentation might look like.
Scenario 1-2: Selecting the Right Type of Networking Model
The ABC Company requires a network that can support 50 users. Which is the correct
type of networking model to use and why?
In this case the best networking model to select is client-server. Client-server
networks are meant for more than 10 users. If a network has 10 users or less, peerto-peer might be acceptable.
Scenario 1-3: Selecting Network Adapters for your LAN Computers
A company you are consulting for requires the installation of five new computers. Each
computer’s network adapter should be able to communicate at 1000 Mbps over its preexisting twisted-pair cabling and should be able to send and receive data simultaneously.
Which Ethernet standard should you select, and what technology should you utilize?
The network adapters should be compliant with the 802.3ab standard allowing them
to transfer 1000 Mbps over twisted pair cabling. You should also configure them for
full duplex mode so that they can send and receive signals at the same time.
Scenario 1-4: Configure the Correct Subnet Mask
A computer is not connecting to certain network devices properly. The IP address
information is as follows:
IP address: 192.168.1.210
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Lesson 1
Subnet mask: 255.254.0.0
How should the subnet mask be configured so that the computer can communicate
properly with all networking devices and other hosts on the network?
The subnet mask should be configured as 255.255.255.0. This is a default Class C
subnet mask that is normally used with IP addresses that start with 192.
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