Class 5

Class 5 ●

Networking quiz

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Notes on networking

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Practical exercises

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Basic network troubleshooting

Start of Networking Quiz...

Wi-Fi is a ●

type of computer

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type of network cable

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set of popular technologies and standards for wireless computer networking set of computer programs that help people make money on the Internet

Wi-Fi is a ●

Wi-Fi is a set of popular technologies and standards for wireless computer networking.

Which of these are forms of Internet service? ●

DSL

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Cable

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Dialup

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ISDN

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Satellite

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All of the above

Which of these are forms of Internet service? ●

DSL, cable, dialup, ISDN and satellite are all forms of Internet service.

A home network router ●

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Makes home computers run faster Enables safe sharing of resources among network devices in the home helps people build Web sites connects a computer to a television so that the video can be shared

A home network router ●

A home network router enables safe sharing of resources among network devices in the home.

An IP address is a numeric quantity that identifies ●

A network adapter to other devices on the network

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The manufacturer of a computer

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The physical location of a computer

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None of the above

An IP address is a numeric quantity that identifies ●

An IP address is a numeric quantity that uniquely identifies a network adapter to other devices on the network.

An IP address ●

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An IP address is the logical address of a network adapter. The IP address uniquely identifies computers on a network. An IP address can be private, for use on a LAN, or public, for use on the Internet or other WAN. IP addresses can be determined statically (assigned to a computer by a system administrator) or dynamically (assigned by another device on the network on demand).

A computer must have an IP address when ●

connecting to a home network router

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connecting to a Wi-Fi hotspot

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communicating with another computer using TCP

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all of the above

A computer must have an IP address when ●

A computer must have an IP address when connecting to a network router, a Wi-Fi hotspot, or another computer via TCP.

A home computer network is sometimes also called a ●

LAN

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MAN

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SAN

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WAN

A home computer network is sometimes also called a ●

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A home computer network is a type of local area network (LAN). A local area network (LAN) supplies networking capability to a group of computers in close proximity to each other such as in an office building, a school, or a home. A LAN is useful for sharing resources like files, printers, games or other applications. A LAN in turn often connects to other LANs, and to the Internet or other WAN.

You can make telephone calls over the Internet using a technology called ●

Intertel

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Telenet

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VoIP

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VoRP

You can make telephone calls over the Internet using a technology called ●

Voice over IP (VoIP) technology allows you to make telephone calls over the Internet using Internet Protocol (IP).

Voice Over IP (VOIP) ●

VoIP converts analog voice signals into digital data packets and supports real-time, two-way transmission of conversations using Internet Protocol (IP).

The purpose of a firewall on computer networks is to ● ●

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prevent computers from overheating prevent unwanted network connections from being made allow more than 4 computers to share the same Internet connection allow pictures and video to be downloaded from a camera to a computer

The purpose of a firewall on computer networks is to ● ●

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prevent computers from overheating prevent unwanted network connections from being made allow more than 4 computers to share the same Internet connection allow pictures and video to be downloaded from a camera to a computer

The purpose of a firewall on computer networks is to ●

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A network firewall prevents unwanted network connections according to filtering / blocking rules set up by the firewall administrator. A network firewall protects a computer network from unauthorized access. Network firewalls may be hardware devices, software programs, or a combination of the two.

Limewire, Kazaa and Bearshare are all examples of ● ● ● ●

brand names of networking hardware products Web sites that store MP3 music files wireless network communication protocols software applications for peer-to-peer (P2P) file sharing

Limewire, Kazaa and Bearshare are all examples of ●

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Limewire, Kazaa and Bearshare are each popular peer-to-peer (P2P) file sharing software programs. A VPN utilizes public telecommunications networks to conduct private data communications. Most VPN implementations use the Internet as the public infrastructure and a variety of specialized protocols to support private communications through the Internet.

You can establish a Virtual Private Network (VPN) connection ● ● ● ●

only when using wireless connections to the Internet only when using Ethernet connections to the Internet only when connected to the Internet none of the above

You can establish a Virtual Private Network (VPN) connection ●

You can establish a Virtual Private Network (VPN) connection over any public network, including (but not limited to) the Internet, and over both wired and wireless links.

Bluetooth technology supports networking over ● ● ● ●

Wi-Fi standard wireless radio connections its own standard wireless radio connections USB cable connections Ethernet cable connections

Bluetooth technology supports networking over ●

Bluetooth is its own wireless radio standard, distinct from Wi-Fi, for networking of computers, cell phones, and other peripheral and consumer devices.

End of networking quiz...Next Some notes on networking...

A Simple Computer Network for File Sharing ●

In a simple network, two computers (or other networkable devices) make a direct connection with each and communicate over a wire or cable.

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Simple networks like this have existed for decades.

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A common use for these networks is file sharing.

A Simple Computer Network for File Sharing

Local Area Network (LAN) with Print ●

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Local area networks often feature a group of computers located in a home, school, or part of an office building. Like a simple network, computers on a LAN share files and printers. Computers on one LAN can also can share connections with other LANs and with the Internet.

A Simple Computer Network for File Sharing

A Hypothetical Wide Area Network ●

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Wide area networks cover a large geographic area like a city, a country or multiple countries. WANs normally connect multiple LANs and other smaller-scale area networks. WANs are built by large telecommunication companies and other corporations using highly-specialized equipment not found in consumer stores. The Internet is an example of a WAN that joins local and metropolitan area networks across most of the world.

A Hypothetical Wide Area Network

Wiring in Computer Networks ●

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In many homes, twisted-pair Ethernet cables are often used to connect computers. Phone or cable TV lines in turn connect the home LAN to the Internet Service Provider (ISP). ISPs, larger schools and businesses often stack their computer equipment in racks, and they use a mix of different kinds of cable to join this equipment to LANs and to the Internet.

Wiring in Computer Networks ●

Much of the Internet uses high-speed fiber optic cable to send traffic long distances underground, but twisted pair and coaxial cable can also be used for leased lines and in more remote areas.

Wiring in Computer Networks

Wireless Computer Networks ●

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Wi-Fi is the standard technology for building wireless home networks and other LANs. Businesses and communities also use the same Wi-Fi technology to set up public hotspots. Next, Bluetooth networks allow handhelds, cell phones and other other peripheral devices to communicate over short ranges. Finally, cellular technology supports voice communications over mobile phones.

Wireless Computer Networks

Network Protocol ●

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A network protocol is like a "language" of rules and conventions for communication between network devices. A protocol includes formatting rules that specify how data is packaged into messages. It also may include conventions like message acknowledgement or data compression to support reliable and/or high-performance network communication.

TCP/IP ●

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Transmission Control Protocol (TCP) and Internet Protocol (IP) are two distinct network protocols. TCP and IP are so commonly used together, however, that TCP/IP has become standard terminology to refer to either or both of the protocols.

TCP/IP ●

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TCP/IP is the protocol suite that drives the Internet. Specifically, TCP/IP handles network communications between network nodes (computers, or nodes, connected to the net).

More on the IP Address ●

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IP addresses or Internet Protocol addresses are the way in which computers on a network both communicate with each other and know where they all are in relation to one another. An IP address is something like a mailing Address for computers on the Internet. This mailing address allows your email to arrive at the right place and your Web page customers to see the correct Web site.

IP Address ●

Most IPv4 addresses are in the format: xxx.xxx.xxx.xxx

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Each set is a number from 0 to 255. So a typical IP address will look something like this: 63.141.53.0

IP Address ●

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If your computer is on an isolated network (meaning, it's not connected to the Internet), it can be assigned any IP address you would like as long as that number is unique on your network. But as soon as that computer is connected to the Internet it needs to be given a registered IP address (which is generally called an Internet address).

TCP/IP Administration ●

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Microsoft Windows XP provides a set of built-in utilities for administering and troubleshooting TCP/IP networks. Each of these utilities runs from the Windows command prompt. From the Start menu, choose Run and type 'cmd' to open a command window, then type in the name of the utility to run.

Ping ●

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'Ping' is the single most powerful troubleshooting tool for networked computers. The ping tool can at different times verify that TCP/IP is installed correctly on a computer, that a computer has joined the network successfully, that a computer can reach the Internet, that a remote Web site or computer is responding, and that computer name resolution is working.

IPConfig ●

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The 'ipconfig' tool shows a computer's TCP/IP configuration. It displays the IP address, the network (subnet) mask and the Internet/network gateway address (if one is set for that network). Use this tool to verify that the TCP/IP configuration has been set up correctly.

Hostname ●

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The 'hostname' utility in Windows XP displays the computer's name. This tool is often used on a computer to verify its name when attempts to map network drives on that computer fail.

Tracert ●

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'Tracert" (pronounced "traceroute") sends a test network message from a computer to a designated remote host and tracks the path taken by that message. Specifically, 'tracert' displays the name or IP address of each intermediate router or other network gateway device the message passes through to reach its destination. 'Tracert' is especially useful when diagnosing connectivity problems on the Internet or within a school or corporate network.

Nslookup ●

The nslookup command can be used in Windows to find the IP addresses of a particular computer, using DNS lookup. The name means "name server lookup". c:\>nslookup www.wikipedia.org Server: ns0.southern.edu Address: 216.229.224.4

Basic Network Troubleshooting ●

If a computer is unable to connect to a network or see other computers on a network, it may be necessary to troubleshoot the network. A network may not work because of any of the below reasons. − − − − −

Network card not connected properly. Bad network card drivers or software settings. Firewall preventing computers from seeing each other. Connection related issues. Bad network hardware.

Basic Network Troubleshooting... ●

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Because of the large variety of network configurations, operating systems, setup, etc... not all of the below information may apply to your network or operating system. Verify Connections / LEDs − Verify that the network cable is properly connected to the back of the computer. In addition, when checking the connection of the network cable, ensure that the LEDs on the network are properly illuminated. −

For example, a network card with a solid green LED or light usually indicates that the card is either connected or receiving a signal. Note: generally, when the green light is flashing, this is an indication of data being sent or received.

Basic Network Troubleshooting... −

If, however, the card does not have any lights or has orange or red lights, it is possible that either the card is bad, the card is not connected properly, or that the card is not receiving a signal from the network.

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If you are on a small or local network and have the capability of checking a hub or switch, verify that the cables are properly connected and that the hub or switch has power.

Basic Network Troubleshooting... ●

Adapter Functionality − Verify that the network card is capable of pinging or seeing itself by using the ping command. Windows / MS-DOS users ping the computer from a MS-DOS prompt. − To

ping the card or the localhost, type either

ping 127.0.0.1

or ping localhost −

This should show a listing of replies from the network card. If you receive an error or if the transmission failed, it is likely that either the network card is not physically installed into the computer correctly, or that the card is bad.