1. A+ Guide to Managing and Maintaining your PC, 6e Chapter 10….. PCs on the Internet

2. A+ Guide to Managing and Maintaining your PC, 6e2 Objectives Learn about the TCP/IP suite of protocols Learn how to connect to the Internet using cable modem, DSL, and dial-up connections and how to share those connections Learn how to use a router to enhance and secure a network connection to the Internet Learn about supporting common Internet clients such as Web browsers, e-mail clients, file transfer software, Internet telephone, and Windows XP Remote Desktop

3. A+ Guide to Managing and Maintaining your PC, 6e3 Introduction Topics to cover –How the TCP/IP suite of protocols is used –Creating and troubleshooting broadband connections –How to create and troubleshoot dial-up connections –How to install and use a router –Supporting Internet applications; e.g., Web browsers

4. A+ Guide to Managing and Maintaining your PC, 6e4 The TCP/IP Suite of Protocols Client/server application –Client application on one PC requests data from server –Server application on another PC returns data Example: World Wide Web –The client is a Web browser –The server is a Web server; e.g., Apache HTTP server –Requested data is a Web page Client applications are installed as programs Server applications are installed as services

5. A+ Guide to Managing and Maintaining your PC, 6e5 Figure 18-1 A Web browser (client software) requests a Web page from a Web server (server software); the Web server returns the requested file or files to the client

6. A+ Guide to Managing and Maintaining your PC, 6e6 Using IP and Port Addresses to Identify Services Port (port address, port number) –Number that identifies server application to client –Server application listens for request at assigned port –Example: port 80 is typically assigned to Web servers Port numbers appear at the end of an IP address –Example: 138.60.30.5:80 A few other common ports and assigned services –Port 20: FTP (File Transfer Protocol) –Port 25: E-mail (using SMTP protocol) –Port 443: Web server (using HTTPS protocol)

7. A+ Guide to Managing and Maintaining your PC, 6e7 Using IP and Port Addresses to Identify Services (continued) Communication protocol –Defines rules of communication between client/server –Example: POP3 is used by client to receive e-mail Information flow between client and server –Application sends request to OS –OS passes request to NIC –NIC places request on network –NIC on receiving end sends request to OS –OS passes request to Web server application –Web server responds by sending data to OS

8. A+ Guide to Managing and Maintaining your PC, 6e8 Common Port Numbers http://www.answersthatwork.com/Download_Area/ ATW_Library/Networking/Network__2- List_of_Common_TCPIP_port_numbers.pdfhttp://www.answersthatwork.com/Download_Area/ ATW_Library/Networking/Network__2- List_of_Common_TCPIP_port_numbers.pdf

9. A+ Guide to Managing and Maintaining your PC, 6e9 TCP/IP Packet

10. A+ Guide to Managing and Maintaining your PC, 6e10 Figure 18-3 Applications, operating systems, and the physical network manage communication at all three levels

11. A+ Guide to Managing and Maintaining your PC, 6e11 TCP/IP Protocol Layers TCP/IP suite lies between applications and the OS API: application programming interface How application protocols are used –Application makes an API call to the OS –The API causes OS to generate a request Request follows format specified by application protocol –After response is passed back, a session is established Example involving HTTP (Hypertext Transfer Protocol) –Web browser makes an API call to the OS –OS makes an HTTP request for a browser

12. A+ Guide to Managing and Maintaining your PC, 6e12 Figure 18-4 How software, protocols, and technology on a TCP/IP network relate to each other

13. A+ Guide to Managing and Maintaining your PC, 6e13 TCP/IP Protocol Layers (continued) Transmission Control Protocol (TCP) –A connection-oriented protocol –Makes a connection, checks delivery, resends data User Datagram Protocol (UDP) –A connectionless or best-effort protocol –Does not guarantee delivery Internet Protocol (IP) –Breaks up and reassembles data into packets –Routes packets to their destination TCP uses IP to establish session and verify delivery

14. A+ Guide to Managing and Maintaining your PC, 6e14 Figure 18-5 TCP turns to IP to prepare the data for networking

15. A+ Guide to Managing and Maintaining your PC, 6e15 TCP/IP Protocol Layers (continued) ARP (Address Resolution Protocol) –Responsible for locating a host on a local network RARP (Reverse Address Resolution Protocol) –Discovers Internet address of host on a local network ICMP (Internet Control Message Protocol) –Communicates problems with a transmission –Example: message deleted due to excessive hops Network protocols used by hardware –Ethernet and PPP (Point-to-Point Protocol)

16. A+ Guide to Managing and Maintaining your PC, 6e16 TCP/IP Utilities TCP/IP component includes a group of utilities –Location: Windows or \Winnt folder Commonly used utilities: Ping, Winipcfg, Ipconfig SNMP (Simple Network Management Protocol) –Provides system management tools for networks Microsoft SNMP Agent –Utility installed after TCP/IP is installed –Used to monitor remote connections Tracert (trace route): shows hops along packet route

17. A+ Guide to Managing and Maintaining your PC, 6e17 Figure 18-9 The Tracert command traces a path to a destination computer

18. A+ Guide to Managing and Maintaining your PC, 6e18 Connecting to the Internet Broadband: supports multiple transmission types Internet Service Provider (ISP) –Connects a PC or network to the Internet Bandwidth technologies used by ISPs: –Regular telephone lines –Cable modem –DSL (Digital Subscriber Line) –ISDN (Integrated Services Digital Network) –Satellite access –Wireless access

19. A+ Guide to Managing and Maintaining your PC, 6e19 Cable Modem and DSL Connections Comparing communication media –Cable modem: TV cables shared by multiple users –DSL: dedicated phone lines Comparing service plans –Both: sliding-scale residential and business plans Comparing setup –Both: a modem interfaces PC and broadband jack Comparing installation services: –Both: will install equipment at additional cost

20. A+ Guide to Managing and Maintaining your PC, 6e20 Figure 18-10 Cable modem connecting to a PC through a network card installed in the PC

21. A+ Guide to Managing and Maintaining your PC, 6e21 Cable Modem and DSL Connections (continued) Overview of installing cable service or DSL –Connect the PC to the cable modem or DSL box –Connect cable modem/DSL box to broadband jack –Plug up power and turn on the broadband device –Configure TCP/IP settings for connection to the ISP –Test connection by using a browser to surf the Web Devices and information needed for an installation –A computer with an available network or USB port –Modem/box and network cable –TCP/IP settings

22. A+ Guide to Managing and Maintaining your PC, 6e22 Figure 18-18 Sample setup for DSL

23. A+ Guide to Managing and Maintaining your PC, 6e23 Dial-Up Connections Based on a modem and regular phone line How dial-up networking works –TCP/IP creates data packets for transport –PPP adds its own header and trailer to data packets –PPP presents packet to modem for delivery on line –Process is reversed when data packet is received Overview of setting dial-up in Windows XP –Install an internal or external modem –Launch New Connection Wizard –Follow directions onscreen

24. A+ Guide to Managing and Maintaining your PC, 6e24 Figure 18-19 PPP allows a PC to connect to a network using a modem

25. A+ Guide to Managing and Maintaining your PC, 6e25 Figure 18-21 The New Connection Wizard asks how to configure the connection

26. A+ Guide to Managing and Maintaining your PC, 6e26 Dial-Up Connections (continued) A few troubleshooting tips –Plug in a regular phone and check line for a dial tone –Try another phone number –Reboot your PC and try again Overview of setting dial-up in Windows 9x/Me –Dial-Up Networking must first be installed A dial-up adapter will also be installed –Install an internal or external modem –Create connection with Make New Connection Wizard –Configure the connection from Properties dialog box

27. A+ Guide to Managing and Maintaining your PC, 6e27 Figure 18-27 Configuring the server type for a connection to the Internet in Windows 9x/Me

28. A+ Guide to Managing and Maintaining your PC, 6e28 Dial-Up Connections (continued) High-speed dial-up: reduces download time by half Enhancements needed to support high-speed dialup –Abbreviated handshake –Data compression –Filtering –Server-side caching –Client-side caching

29. A+ Guide to Managing and Maintaining your PC, 6e29 Figure 18-30 Server-side caching and client-side caching improve download times by reducing the number of requests for data

30. A+ Guide to Managing and Maintaining your PC, 6e30 Sharing a Personal Internet Connection Networked PCs access Internet through a host Connecting two PCs –Single crossover network cable links two PCs –Host PC connects to the modem Connecting three or more PCs –PCs connect to hub/switch using patch cables –Host connects to modem via USB cable Internet Connection Sharing (ICS) –Manages shared Internet connections –Enables host to use NAT and act as proxy server

31. A+ Guide to Managing and Maintaining your PC, 6e31 Figure 18-31 Two or more networked computers can share a single Internet connection

32. A+ Guide to Managing and Maintaining your PC, 6e32 Network Address Translation

33. A+ Guide to Managing and Maintaining your PC, 6e33 Implementing a Software Firewall Guidelines for protecting your PC –Keep Windows updates current –Use a software or hardware firewall –Run antivirus software and keep it current Services provided by a hardware or software firewall –Firewalls can filter data packets –Firewalls can filter ports –Firewalls can block certain activity within the network –Firewalls can filter inappropriate information Example of a software firewall: Windows Firewall

34. A+ Guide to Managing and Maintaining your PC, 6e34 Figure 18-34 Windows Firewall is set for maximum protection

35. A+ Guide to Managing and Maintaining your PC, 6e35 Using a Router on Your Network Disadvantages of using a host to share a connection –Host computer must always be turned on –Only low-level security for your network –Bottlenecks at host can slow traffic within network Solution: use a router to interface with the Internet Router provides two functions –Takes place of host as gateway to the Internet –Serves a hardware firewall to protect your network

36. A+ Guide to Managing and Maintaining your PC, 6e36 Figure 18-36 A router stands between the Internet and a local network

37. A+ Guide to Managing and Maintaining your PC, 6e37 Advantages of Using a Router Host PC will not be a performance bottleneck Internet access is not dependent on running host Router can also serve as a hardware firewall The router can provide additional features –DHCP server, switch, or wireless access point Example: Wireless-G Broadband Router by Linksys

38. A+ Guide to Managing and Maintaining your PC, 6e38 Figure 18-37 This Linksys router allows computers on a LAN to share a broadband Internet connection and is an access point for computers with wireless adapters

39. A+ Guide to Managing and Maintaining your PC, 6e39 Installing and Configuring a Router Run the setup program on any network PC Connect the cable or DSL modem to the router –Follow the instructions on the setup screen Connect PCs on your network to your router –PC can connect directly to a network port –You can also connect a switch or hub to the router Plug in the router and turn it on Sign in with default password and then reset it

40. A+ Guide to Managing and Maintaining your PC, 6e40 Installing and Configuring a Router (continued) Configuring a router (using Linksys as an example) –Access configuration program on router firmware Enter the IP address of the router (192.168.1) –View and/or change default settings in Setup window Configure a hardware firewall –Settings in Security tab and Access Restrictions tab Port filtering: open or close certain ports for use Port forwarding –Request to certain ports forwarded to certain PCs –Local PC must have static address for this service

41. A+ Guide to Managing and Maintaining your PC, 6e41 Figure 18-39 Basic Setup screen used to configure the router

42. A+ Guide to Managing and Maintaining your PC, 6e42 Figure 18-42 With port forwarding, a router allows requests initiated outside the network

43. A+ Guide to Managing and Maintaining your PC, 6e43 Virtual Private Network How VPN security works –Remote user sends id to authentication server –Authentication server encrypts data Various encryption protocols are used; e.g., CHAP –Tunnel is created so all data transferred is encrypted Various tunneling protocols are used; e.g., PPP How to configure a router to support VPN –Select encryption and tunneling protocols –Configure each tunnel the VPN will support Configure client for VPN from Network Connections

44. A+ Guide to Managing and Maintaining your PC, 6e44 Figure 18-45 With a VPN, tunneling is used to send encrypted data over wired and wireless networks and the Internet

45. A+ Guide to Managing and Maintaining your PC, 6e45 Figure 18-48 Properties window of a VPN connection

46. A+ Guide to Managing and Maintaining your PC, 6e46 Supporting Internet Clients Section task: support Internet clients Common Internet clients –Web browsers –E-mail –FTP –VoIP –Windows XP Remote Desktop

47. A+ Guide to Managing and Maintaining your PC, 6e47 Supporting Web Browsers Web page: text file with an.htm or.html extension –Coded in HTML (Hypertext Markup Language) Web browser: requests pages from a Web server Uniform Resource Locator (URL): Web page address Components of a URL –Protocol, host name, network name, folder, file name –Domain name = host name + network name –Example: http://www.course.com/myfolder/myfile.htmlhttp://www.course.com/myfolder/myfile.html Name resolution service relates name to IP address

48. A+ Guide to Managing and Maintaining your PC, 6e48 Figure 18-49 A URL contains the protocol used, the host name of the Web server, the network name, and the path and filename of the requested file

49. A+ Guide to Managing and Maintaining your PC, 6e49 Table 18-3 Suffixes used to identify top-level domain names

50. A+ Guide to Managing and Maintaining your PC, 6e50 Supporting Web Browsers (continued) Examples of Web browser software –Firefox by Mozilla, Internet Explorer (IE) by Microsoft Some configuration tasks you can perform in IE –Configure the pop-up blocker –Manage IE add-ons –Set Internet Explorer security levels –Control how and if scripts are executed –Configure ActiveX controls –Control proxy settings

51. A+ Guide to Managing and Maintaining your PC, 6e51 Figure 18-53 Set the security level of Internet Explorer using the Internet Options window

52. A+ Guide to Managing and Maintaining your PC, 6e52 Supporting Web Browsers (continued) Solving Internet Explorer problems –First perform routine maintenance; e.g., run ScanDisk –Clean out cache that IE uses to hold temporary files –Suppress downloading images –Repair a corrupted Internet Explorer cache –Run antivirus software –Update Internet Explorer –Verify Windows system files using System File Checker –Remove and reinstall Internet Explorer 6

53. A+ Guide to Managing and Maintaining your PC, 6e53 Figure 18-56 Use the Internet Options window to control the Internet Explorer environment

54. A+ Guide to Managing and Maintaining your PC, 6e54 Supporting Web Browsers (continued) Digital certificate: identification plus public key SSL (Secure Sockets Layer) –Encryption system using a digital certificate –Data is encrypted with public key –Data is decrypted with a private key TLS (Transport Layer Security) –An improved version of SSL HTTPS (HTTP secure) –Can mean HTTP over SSL or HTTP over TLS –Indicates secure protocol being used is SSL or TLS

55. A+ Guide to Managing and Maintaining your PC, 6e55 Figure 18-61 Using secure HTTP, a Web server and browser encrypt data using a public key before the data is transmitted

56. A+ Guide to Managing and Maintaining your PC, 6e56 Supporting E-mail SMTP: Simple Mail Transfer Protocol SMTP AUTH (SMTP Authentication): improved SMTP POP: Post Office Protocol IMAP4: Internet Message Access Protocol, version 4 Route traveled by e-mail –Client sends e-mail to client e-mail server using SMTP –Client e-mail server sends e-mail to recipient with SMTP –Recipient’s e-mail server forwards e-mail to recipient Recipient’s e-mail server uses POP or IMAP4 Recipient must first login and request e-mail from server

57. A+ Guide to Managing and Maintaining your PC, 6e57 Figure 18-63 The SMTP protocol is used to send e-mail to a recipient’s mail server, and the POP3 or IMAP4 protocol is used to download e-mail to the client

58. A+ Guide to Managing and Maintaining your PC, 6e58 Supporting FTP File Transfer Protocol (FTP) –Used to transfer files between two computers FTP server (or FTP site) –Application running on another server; e.g., Unix server FTP from a command prompt –Connection to a network must first be established –Some commands: FTP, get yourFile.dat File transfer using FTP software –FTP utility software: can be downloaded from Internet –Web browser: change protocol used in address bar

59. A+ Guide to Managing and Maintaining your PC, 6e59 Figure 18-68 Using Internet Explorer as an FTP client

60. A+ Guide to Managing and Maintaining your PC, 6e60 Supporting VoIP VoIP (Voice-over-IP) –Provides voice communication over a network Two types of phones used in VoIP service –Digital telephone: plugs into a network port –Analog phone: needs Analog Telephone Adapter (ATA) Special requirements of VoIP –Phones must be assigned number by VoIP provider –Phones are programmed to use dynamic IP addressing –Each network cable to phone needs a ferrite clamp

61. A+ Guide to Managing and Maintaining your PC, 6e61 Figure 18-70 Use this ATA to turn an analog telephone into an Internet phone

62. A+ Guide to Managing and Maintaining your PC, 6e62 Supporting Remote Desktop Windows XP Professional Remote Desktop –Gives user access to desktop from remote locations –Server must be running Windows XP Professional –Client can run Windows XP Home Ed. or Professional Accessing a Remote Desktop –Open the Remote Desktop Connection window –Enter address of PC, identification, resources needed Preparing a Remote Desktop for first use –Configure the computer for static IP addressing –Configure Remote Desktop for service

63. A+ Guide to Managing and Maintaining your PC, 6e63 Figure 18-75 The desktop of the remote computer is available on your local computer

64. A+ Guide to Managing and Maintaining your PC, 6e64 Summary Internet communication is based on the client/server model TCP/IP: suite of protocols facilitating transfer of data between client and server Bandwidth technologies: telephone lines, DSL, cable modem, ISDN, satellite access, wireless access Internet Connection Sharing (ICS): manages shared Internet connections Firewall: blocks and filters incoming network traffic

65. A+ Guide to Managing and Maintaining your PC, 6e65 Summary (continued) Router: manages traffic between two networks Web browser: loads and displays Web pages E-mail client: used to send and receive e-mail FTP client: used to transfer files over the Internet VoIP service: provides voice communications over the Internet