1. PC Maintenance: Preparing for A+ Certification Chapter 25: The Internet

2. Chapter 25 Objectives Choose and set up an Internet connection method Choose and set up an Internet connection method Understand IP addressing and TCP/IP Understand IP addressing and TCP/IP Identify Internet protocols such as FTP, HTTP, and Telnet Identify Internet protocols such as FTP, HTTP, and Telnet Configure Internet Explorer Configure Internet Explorer Configure Outlook Express Configure Outlook Express Troubleshoot Internet connections Troubleshoot Internet connections

3. What is the Internet? Huge TCP/IP-based network Huge TCP/IP-based network Physical mesh topology Physical mesh topology Traffic passes through a complex system of routers Traffic passes through a complex system of routers Addresses are translated between domain names and IP addresses by DNS servers Addresses are translated between domain names and IP addresses by DNS servers

4. TCP/IP and the OSI Model

5. Ways to Connect to the Internet Modem Modem ISDN ISDN DSL DSL Cable Cable Satellite Satellite

6. IP Addresses on the Internet A company has a range of IP addresses it can use on the Internet A company has a range of IP addresses it can use on the Internet Many times a company has more users than IP addresses available Many times a company has more users than IP addresses available Network Address Translation (NAT) is used to dynamically assign one of the available IP addresses as needed to a node Network Address Translation (NAT) is used to dynamically assign one of the available IP addresses as needed to a node

7. Static and Dynamic IP Addresses Dynamic: Assigned by an ISP to an end- user; might change each time user connects Dynamic: Assigned by an ISP to an end- user; might change each time user connects Static: Typically given to a server or other resource where the address must not change Static: Typically given to a server or other resource where the address must not change

8. Internet DNS Servers Domain Name System Domain Name System In example address www.emcp.com: In example address www.emcp.com: Top-level DNS server translates the rightmost portion of the address (example:.com) Top-level DNS server translates the rightmost portion of the address (example:.com) Second-level DNS server translates next portion of the address (example: emcp) Second-level DNS server translates next portion of the address (example: emcp)

9. TCP/IP Communication Protocols IP addressing occurs at Network Layer (3) IP addressing occurs at Network Layer (3) TCP occurs at Transport Layer (4) TCP occurs at Transport Layer (4) Session and Presentation layers can have different protocols in use such as: Session and Presentation layers can have different protocols in use such as: HTTP HTTP FTP FTP Telnet Telnet E-mail protocols E-mail protocols

10. Common Layer 5 and 6 Protocols Hypertext Transfer Protocol (HTTP) Hypertext Transfer Protocol (HTTP) Used to deliver Web content to a Web browser application Used to deliver Web content to a Web browser application File Transfer Protocol (FTP) File Transfer Protocol (FTP) Used to upload and download files Used to upload and download files HTTP can also download files, but FTP is more efficient HTTP can also download files, but FTP is more efficient Telnet Telnet An old protocol for terminal emulation An old protocol for terminal emulation

11. E-mail Protocols Post Office Protocol (POP, or POP3) Post Office Protocol (POP, or POP3) Used for receiving e-mail with an e-mail application such as Outlook Used for receiving e-mail with an e-mail application such as Outlook Retrieves messages from the server and deletes them from the server Retrieves messages from the server and deletes them from the server

12. E-mail Protocols Internet Message Access Protocol (IMAP) Internet Message Access Protocol (IMAP) Used for receiving e-mail with either an e-mail application or an IMAP-enabled Web interface Used for receiving e-mail with either an e-mail application or an IMAP-enabled Web interface Messages remain stored on the server Messages remain stored on the server Useful for people who access their mail from multiple locations Useful for people who access their mail from multiple locations

13. E-mail Protocols Simple Mail Transfer Protocol (SMTP) Simple Mail Transfer Protocol (SMTP) Used for sending e-mail (not receiving) Used for sending e-mail (not receiving) Hypertext Transfer Protocol Hypertext Transfer Protocol Used for Web-based e-mail applications such as Hotmail and Yahoo Mail Used for Web-based e-mail applications such as Hotmail and Yahoo Mail

14. Security Preferences in Internet Explorer Choose Tools > Internet Options and click the Security tab Choose Tools > Internet Options and click the Security tab Drag the slider to change the security level for the selected zone Drag the slider to change the security level for the selected zone

15. Privacy Preferences in Internet Explorer Choose Tools > Internet Options and click the Privacy tab Choose Tools > Internet Options and click the Privacy tab Control the usage of cookies Control the usage of cookies Set certain Web sites to always or never be allowed to use cookies Set certain Web sites to always or never be allowed to use cookies

16. Privacy Preferences in Internet Explorer Turning off AutoComplete can give greater privacy Turning off AutoComplete can give greater privacy Turn it on/off from Content tab of Internet Options dialog box Turn it on/off from Content tab of Internet Options dialog box

17. Outlook Express Default mail application in Windows Default mail application in Windows Sends and receives e-mail Sends and receives e-mail Views and posts to USENET newsgroups Views and posts to USENET newsgroups Each Windows version comes with a different version of Outlook Express Each Windows version comes with a different version of Outlook Express Windows 95 came with Internet Mail and Internet News instead Windows 95 came with Internet Mail and Internet News instead

18. Setting Up an E-mail Account 1. In OE, choose Tools > Accounts 2. Click Add, then click Mail 3. Follow the prompts in the Internet Connection Wizard

19. Filtering Out Junk Mail 1. In OE, choose Tools > Message Rules > Mail 2. Create a new Mail Rule

20. Transferring Files with FTP Stand-alone FTP application Stand-alone FTP application Many shareware and trial versions available Many shareware and trial versions available FTP through Internet Explorer FTP through Internet Explorer Usually download only Usually download only Command-line FTP access Command-line FTP access Can be difficult to memorize command syntax Can be difficult to memorize command syntax

21. FTP through Internet Explorer

22. FTP through an FTP Application

23. FTP through a Command Line

24. Sharing an Internet Connection Cable/DSL Router Cable/DSL Router Internet Connection Sharing Internet Connection Sharing Windows 98 Second Edition Windows 98 Second Edition Windows Me Windows Me Windows XP Windows XP

25. Troubleshooting Internet Problems No Web, No E-mail No Web, No E-mail Check connectivity Check connectivity Reset terminal adapter Reset terminal adapter Reboot PC Reboot PC Use ping to check a well-known site Use ping to check a well-known site

26. Troubleshooting Internet Problems Web but No E-mail Web but No E-mail Mail account might not be set up correctly Mail account might not be set up correctly Mail server might temporarily be down Mail server might temporarily be down E-mail but No Web E-mail but No Web Try bypassing proxy server if possible (from Connection tab of Internet Options) Try bypassing proxy server if possible (from Connection tab of Internet Options) No Access to Specific Web Site No Access to Specific Web Site Ping Ping Tracert Tracert