PC Support & RepairChapter 8Fundamental Networks

Objectives• After completing this chapter, you will meet these objectives:▫ Explain the principles of networking. ▫ Describe types of networks. ▫ Describe basic networking concepts and technologies. ▫ Describe the physical components of a network. ▫ Describe LAN topologies and architectures. ▫ Identify standards organizations. ▫ Identify Ethernet standards. ▫ Explain OSI and TCP/IP data models. ▫ Describe how to configure a NIC and a modem. ▫ Identify names, purposes, and characteristics of other technologies used to

establish connectivity. ▫ Identify and apply common preventive maintenance techniques used for networks. ▫ Troubleshoot a network.

Computer Networks• 2 or more devices connected by networking equip.• Host▫Devices that can send/receive on a network

• Peripheral▫Device connected to a host (needs host to operate)

• Examples of each???

•Name devices that can connect to a network.

•What resources can a network share?

How do devices link?•Copper▫Ethernet▫Sends electricity through cable

•Fiber Optic▫Uses glass fibers to carry light pulses

•Wireless▫Uses radio signals

Benefits of Networking•Fewer peripherals▫One printer, one storage device, etc

• Increased Communication▫Email, chat, etc.

• Lower Cost Licensing▫For software▫Site license costs less than single license

•Central Administration▫Manage & backup from one location

Activity

Describe Types of Networks•Describe a LAN. •Describe a WAN. •Describe a WLAN. •Explain peer-to-peer networks. •Explain client/server networks.

LAN•Small area•Under one admin

control (access policy)•GCIT is a LAN•Your home is a LAN

WAN•Connects LANs that are

far away• Internet is biggest WAN

WLAN• LAN with wireless•Wireless devices

connect to AP▫AP connects to wired

part of network•Avg. distance inside is

100ft▫Outside is more

Activity

Review•Which type of network includes an AP?▫WLAN

•The Internet is which type of network?▫WAN

•Explain what an AP does.▫Connects wireless devices to the wired network

•Why does some software cost less on a network?▫May be able to get site license

•What does an Ethernet cable use to send data?▫Electricity

Peer to Peer Networks• Your house network•No server• Individual PC controls its own

resources▫No one computer in charge▫No needs for administrator

• Best for 10 or less computers• D: No admin to control network, no

centralized security, difficult to manage, no centralized data storage

Client-Server Networks•Client requests, server provides

service•Administrators▫Maintain servers & control user

access•Users have password for net

access•Access central storage▫Backed up daily

Client-Server Networks•Workgroup▫Collection of PC’s & servers designed to communicate

with each other▫Each computer has its own account security log in

•Domain▫Logical grouping of computers, may be far away▫Domain controller server manages them▫You can log into any computer in the domain

Review•Which type of network would daily backups be done on?▫Client-server

•Which network would have better, secure access?▫Client-server

•Which network would you typically store data on your own hard drive?▫Peer to peer

•Which specific network type is managed from a central server because the computers may be in far away locations?▫Domain

Basic Concepts & Technologies•Explain bandwidth and data transmission. •Describe IP addressing. •Define DHCP. •Describe Internet protocols and applications. •Define ICMP.

Bandwidth• Amount of data transmitted in a time period• Data is broken into chunks, called packets▫Packets have headers which tell how to put the chunks back

together• bps – bits per second • kbps – kilobits per second •Mbps – megabits per second

• Latency▫Time it takes data to travel▫More devices = more latency

BandwidthPicture Example

Data Transmission Modes•Simplex▫Unidirectional, one-way

•Half-Duplex▫Send OR receive at a time

•Full-Duplex▫Send AND receive at same time▫Better for network▫100Mbps Ethernet and more

MAC & IP Addresses•NIC has a MAC address▫Burned onto card; unique; PHYSICAL▫ID’s your physical PC▫Like your fingerprint; ID’s you▫Attaches FRAME to packet for NIC to identify

• IP identifies where a host is on network▫Location to find you; mailing address▫Each MUST be unique; LOGICAL▫Must have to communicate

Review•Which transmission mode allows “talking/listening”

at the same time?▫Full-duplex

•Which mode works like a walkie-talkie?▫Half-duplex

•Which address is burned in the NIC?▫MAC address

•Which address can be changed in software?▫IP address

IP Address• 32 bits▫Four octets of 8 bits▫Network & host portion of

address▫Routers read network

portion only To send to correct network

• 192.168.2.16▫Network is 192.168.2▫ .16 is the host portion

IP Address Classes

Subnet Mask•Helps determine what

network an address is on

•All hosts in a LAN have same SM

•There are default SM for each class▫Can subnet (split)

Manually Enter IP & SM•TCP/IP properties in NIC

•Easy to do in a small net

• Large nets use DHCP▫Auto assign of IP & SM

Communication Example

Lab•Handout• ID the class of each address

DHCP• Dynamically assigns IP

addresses to hosts▫DHCP Server manages the

process▫You give it a list to give out▫Address given out for a

time After time expires, it goes

back into list to give out▫Gives out: IP, SM, Default

Gateway, DNS

DHCP• If it can’t connect to DHCP server, Windows gives PC

an address▫169.254.0.0 to 169.254.255.255▫You won’t be able to communicate▫Automatic Private IP Addressing (APIPA)▫Every 5 min. it tries to talk to DHCP for real address

•NAT▫Translates a private, internal address to communicate

over Internet▫How your home network, school, most businesses do it

Ipconfig or ipconfig /all

Protocols•Set of rules for communication▫Common Protocols used in communications

Protocol Port # Information

TCP/IP N/A Rules to transmit data

HTTP 80 Connection to transfer web pages

HTTPS 443 Secure connection for web pages transmission

FTP 20/21 File transfer

Telnet 23 Remote login

SSH 22 Secure remote login

POP3 110 Transfer of email from email server to you

IMAP 143 Transfer of email from email server to you

SMTP 25 Used to send email between email servers

Activity•Activity & Review Handout

ICMP•Sends control message for troubleshooting•PING▫Command line test for connectivity▫Ping an IP address▫Echo request/reply 4x default▫Ping a website to get the IP address

Review•Which protocol is used for web page transmission on

port 80?▫HTTP

•Which command will display a computer’s IP address?▫ Ipconfig

• You have a network of 100 devices. Which process will easily allow all computers to automatically be able to communicate on a network by assigning IP addresses?▫DHCP

Review•Your computer has an IP address of 169.254.1.1. What

does this mean to you?▫It did not get an IP from the DHCP server

•Which class address is 201.17.55.9?▫C

•Which utility can test connectivity?▫Ping

•Which protocol allows remote login, but is not secure?▫Telnet

Physical Components of a Network

• Identify names, purposes, and characteristics of network devices.

• Identify names, purposes, and characteristics of common network cables.

Hubs•Simple•Extends network•Data goes in one port & out all

others▫No thinking involved▫Relies on devices to decide on

message•Creates more network traffic

Hub Network

Switch•Data sent in small packets•MAC addresses added▫Packaged into a FRAME

•Data enters a port, then sent out the one port▫Smarter than bridge▫Knows MAC address on

each port MAC address table

Switch Network

Router•Connects different

networks•Reads IP addresses▫Directs packets to

networks▫Doesn’t care about

specific PC’s

Router Network

Wireless Access Point (WAP)•Allows wireless devices

to connect to wired network▫Uses radio waves

• Limited range▫May have several in

building

Multipurpose Device•Router, Switch, WAP; all in one

Review•This device connects networks.▫Router

•This basic device extends the network, as it does not segment it.▫Hub

•You are asked to install equipment that will allow laptops with wireless cards to gain access to your existing wired network. What equipment is this?▫Wireless access point

Review•Which current networking devices receives data and sends it

out a single port based on MAC addresses?▫Switch

•What address does a router use to make a decision about sending data to the correct network?▫ IP address

• If a device can connect you to other networks, allow multiple computers to connect to it, allow wireless devices to connect to it, and it assigns IP addresses, then what kind of device is it?▫Multi-purpose device (all in one)

Cables- Twisted-Pair• Ethernet• 8 wires, 4 pairs▫1 pair transmit; 1 pair receive

•UTP▫Most common▫100m (328ft)▫ Interference prone (EMI/RFI)

• STP▫Each pair is shielded ($$ & thicker)▫Reduces interference

UTP Category of Cables•Cat 3 for phones▫RJ11 connector▫2 or 4 pins/wires

•Cat 5, 5e, 6▫RJ45 connector▫8 pins/wires▫5e has more twists

Coax Cable•Copper shielding•RG-6•TV•Used to be used in

networks▫Slower speed 10Mbps

Fiber Optic Cable•Glass or plastic core• Protective jacket• Sends light pulses▫Not prone to EMI/RFI▫No electricity or radio waves

• Faster, longer distances, $$$•Multimode▫Thick cable, shorter distances

• Single-mode▫Thinner, uses laser, long distances

Activity•Packet Tracer Lab▫Create a network & cable it

Review• You need to select a cable to connect GCIT to GCC.

Which network cable would you choose?▫Fiber optic (single-mode)

•Which kind of cable would you attach to your PC?▫Cat 5/5e/6

• T or F. A cat 6 cable can reach further distances than a Cat 5 cable.▫False; all Ethernet can only go 100m.

•What is the difference between the different categories?▫Twists of wires inside the cable

Review•What’s the difference between a Cat 3 & 5 cable?▫Number of wires inside

•T or F. A coax cable has more shielding than UTP.▫True

•Which cable is resistant to lightning, EMI, & RFI?▫Fiber optic

•Which cable has 4 pairs of wires and is less susceptible to EMI & RFI?▫STP

Describe LAN topologies

•Describe LAN topologies. •Describe LAN architectures.

Physical Topologies

Logical Topologies•How data travels

•Broadcast (Bus)▫First come, first served▫Ethernet

•Token▫OLD▫Token passed; must have token to talk

Ethernet•Star or Extended Star Physical Topology•Broadcast or Bus Logical Topology•Cat 6, 5e, 6•Twisted Pair cabling•100Mbps or 1000Mbps•100m max (328 ft)

Review•What is the max distance Ethernet can go in feet?▫328 feet

•Which topology is used today and has one central point of connection & failure?▫Star

•Which topology has lots of connections to each other & can continue to work if one wire fails?▫Mesh

• Ethernet is a logical bus topology, which means what?▫First come, first served

Review•Which physical topology do all devices connect to a

single line?▫Bus

•Which logical topology passes something that, when you get it, allows you to communicate?▫Token

Ethernet Standards

•Explain cabled Ethernet standards. •Explain wireless Ethernet standards.

Ethernet Standards• IEEE 802.3•CSMA/CD•Star/Ext. Star with broadcast/bus•100Mbps or 1000Mbps (Gigabit)•10Base-T or 100Base-TX or 1000Base-TX▫100 (speed) Base (baseband) T or TX (twisted pair)

•100m max•EMI/RFI

Wireless Ethernet Standards

Review•Ethernet is governed under what standards?▫IEEE 802.3

•Which logical topology does Ethernet use?▫Bus

•Which wireless standard can have speeds up to 54Mbps using 2.4GHz frequency?▫802.11g

•Which wireless standard is the slowest?▫802.11b

OSI Model

•Define the OSI model.

OSI Model•Virtual model to

standardize communication process

•Encapsulation

Activity•OSI Model & Handout

Review•As data is passed from one layer to the next, control

info (headers) are added. What term describes this adding of info to the data through the layers?▫Encapsulation

•Which layer of the OSI deals with IP addresses?▫Network

•Which layer of the OSI deals with MAC addresses and gaining access to the cables?▫Data Link

Configure a NIC

• Install or update a NIC driver. •Attach the computer to an existing network. •Test the NIC.

NIC Driver•Get from

manufacturer’s web site

Connect NIC• Attach cable• Look at LEDs▫Connection Link Light▫Activity Light▫No light. What’s problem?

• Set IP or DHCP•Use ipconfig• Ping your own IP & another▫Tests end to end connectivity

Lab•8.9.2•Packet Tracer Lab

Other Connection Technologies

•Describe telephone technologies. •Define power line communication. •Define broadband. •Define VoIP.

Telephone Tech•POTS▫Analog, 56k slow, no voice calls & Internet at same

time

• ISDN▫Digital, slightly faster than POTS▫BRI/PRI services (channels)

“B” channels for voice/data “D” channel for signaling

Telephone Tech•ADSL▫“Asynchronous” =

different Download/upload

speeds differ▫Distance limits, filters

needed

Broadband•So what is it?▫Sending multiple signals over one cable▫Cable & Internet to house on one cable

•Cable Modem, DSL, Satellite, Fiber Broadband (FiOS)

VoIP•Calls over data networks

& Internet▫Can connect to PSTN

•No Internet= no calls

VPN•Using the Internet to connect to remote sites▫Dedicated, secure connection▫You have access to all resources on that network▫You need a VPN client installed on your PC

Data gets encrypted

Review• In order to use a VPN, what is needed on the remote

computer?▫VPN client software installed

•What process helps prevent collisions in data transmission by listening for silence before sending?▫CSMA/CD

•Which connection is broadband over phone lines & has different upload/download speeds?▫ADSL

• ISDN has B & D channels. What is on each?▫B- data; D- control info

Troubleshooting• Ipconfig, ipconfig/all•Ping• tracert

Counterfeit Devices•Some products exits that are not really from

manufacturer▫Cheaply made▫Invalid warranty & licenses▫Won’t meet safety standards▫Cheaper to buy, more $$ to maintain▫Less performance▫Packaging not as good▫Contact Cisco Brand Protection Team

•Purchase from authorized dealers or manufacturer

Review- 14 Questions

PC Support & RepairChapter 8Fundamental Networks