PC Support & Repair Chapter 8 Fundamental 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 ▫ , 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

Bandwidth Picture 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 ▫ Network is ▫.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 ▫ to ▫ 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 ProtocolPort #Information TCP/IP N/ARules to transmit data HTTP 80Connection to transfer web pages HTTPS 443Secure connection for web pages transmission FTP 20/21File transfer Telnet 23Remote login SSH 22Secure remote login POP3 110Transfer of from server to you IMAP 143Transfer of from server to you SMTP 25Used to send between 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 What does this mean to you? ▫ It did not get an IP from the DHCP server Which class address is ? ▫C▫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 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 Which logical topology does Ethernet use? ▫ Bus Which wireless standard can have speeds up to 54Mbps using 2.4GHz frequency? ▫ g Which wireless standard is the slowest? ▫ b

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 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 & Repair Chapter 8 Fundamental Networks