Copyright © 2007 Heathkit Company, Inc. All Rights Reserved PC Fundamentals Presentation 49 – Introduction to the Internet

2 Objectives At the end of this presentation, you will be able to:

3 Define TCP/IP and explain its importance to the Internet. Define Internet, Intranet, and Extranet. Define “fully qualified domain name (FQDN)” and URL and define the major parts of each. Recognize top-level domains. Explain how the Domain Name System (DNS) works.

4 The Internet A “Network of Networks”. It consists of tens of thousands of networks and millions of computers all over the world.

5 A Brief History of the Internet Late 1960s – ARPANET - Research in packet-switching networking carried out by the Advanced Research Projects Agency – ARPANET turned over to the U.S. Defense Communication agency – Internet Control and Configuration Board formed – Global Internet begins to emerge as conversion to TCP/IP begins.

6 A Brief History of the Internet 1983 – ARPANET split into ARPANET and MILNET – Defense Department mandates TCP/IP as the protocol of the ARPANET – National Science Foundation funds new backbone called NSFNET, which connects to and greatly expands ARPANET and provides seed money for regional networks. 1980s – Universities and major scientific research institutes get involved.

7 A Brief History of the Internet Late 1980s – Major Corporations tie into the still emerging Internet. Early 1990s – Medium and small companies begin connecting in large numbers. Mid 1990s – Individuals begin connecting en mass. Late 1990s – E-Commerce emerges. Today – The Internet is an integral part of our lives.

8 TCP/IP is: The Protocol of the Internet The number 1 protocol in the world for moving data around A suite of over 100 protocols Supported by virtually all modern operating systems. The protocol of UNIX.

9 TCP/IP- A suite of protocols Internet Protocol (IP) - The protocol that determines the Internet’s basic packet structure and its addressing scheme. Transmission Control Protocol (TCP) - The protocol that sets up a connection between two hosts and ensures that data is passed between them reliably.

10 TCP/IP- A suite of protocols File Transport Protocol (FTP) - Defines file transfers among computers on the Internet. Simple Mail Transport Protocol (SMTP) - Describes the format of Internet . Hypertext Transfer Protocol (HTTP) - Defines how WWW data is transmitted between a server and a browser. Network News Transport Protocol (NNTP) - Defines how Usenet newsgroups and postings are transmitted.

11 IP Address A logical rather than a physical address. How it is entered into your computer: – Manually, by you or the network administrator. – Automatically, via the Dynamic Host Configuration Protocol (DHCP).

12 Each computer on a network that uses the TCP/IP protocol must have its own unique IP address.

13 IP Address Dotted-Decimal Notation

14 Usually, you get your IP addresses from your local Internet Service Provider.

15 Configuring TCP/IP Manually Automatically through DHCP

16 The IP Address is divided into two parts: Network ID (Assigned by InterNIC) Host ID (Assigned locally)

17 Networks using Internet Technology Internet internet Intranet Extranet

18 Network 1 Network 2 Router

19 Network 1 Network 2 Router 1 Network 3 Router 2

20 Network 1 Network 2 Router 1 Network 3 Router 2 Router 3

21 Net5 R Net13 R Net6 R Net7 R Net9 R Net10 R Net1 R Net2 R Net8 R Net11 R Net14 R Net3 R Net4 R Net15 R Net16 R Net12 R

22 Addressing and Identification Schemes MAC Address0A:12:B3:00:F1:3C IP Address Domain Name Uniform Resource Locator (URL)

23 Domain Names An Internet identification system that uses words rather than numeric IP addresses. The Internet uses a system of “Domains” to divide and name its resources. Example:

24 Commercial Ford GE IBM NASA NPS Government HUD MIT ND UNC Education

25 Commercial Ford GE IBM Top-Level Domain Second-Level Domain Domain Names: Ford.com GE.com IBM.com

26 Top-Level Domain Second-Level Domain Domain Names: NASA.gov NPS.gov HUD.gov NASA NPS Government HUD

27 Top-Level Domain Second-Level Domain Domain Names: MIT.edu ND.edu UNC.edu MIT ND UNC Education

28 Commercial yahoo shopping news sports Top-Level Domain 2nd-Level Domain 3rd-Level Domain sports.yahoo.com shopping.yahoo.com Dailynews.yahoo.com

29 Fully Qualified Domain Name (FQDN) Samson.Finance.Mycompany.com Host 3 rd Level Domain 3 rd Level Domain 2nd Level Domain 2nd Level Domain Top Level Domain Top Level Domain

30 Top Level Domains.comCommercial.govGovernment.eduEducation.netNetworks.orgOrganizations.milMilitary.intInternational Country Codes

31 Country Codes.cn China.ca Canada.de Germany.dk Denmark.fr France.hk Honk Kong.ru Russia.se Sweden.uk United Kingdom.us United States

32 Uniform Resource Locator (URL) The Addressing Scheme of the World Wide Web. A user-friendly substitute for an IP Address Example:

33 Protocol Domain Name Domain Name Path File World Wide Web World Wide Web

34 Domain Name System (DNS) A world-wide distributed data base that links Domain Names to IP addresses. A system of hierarchical routing which automatically finds the proper numeric IP address when it is given a Domain Name.

35 DNS Servers

36 Your Workstation DNS Server Hey, DNS Server! What is the IP address of: shopping.yahoo.com ? Hey, DNS Server! What is the IP address of: shopping.yahoo.com ?

37 Your Workstation DNS Server I don’t know. But here is the IP address of the yahoo.com name server She can tell you. I don’t know. But here is the IP address of the yahoo.com name server She can tell you.

38 Your Workstation YAHOO.COM Name Server Hey, Yahoo.com name server! What is the IP address of: shopping.yahoo.com ? Hey, Yahoo.com name server! What is the IP address of: shopping.yahoo.com ?

39 Your Workstation YAHOO.COM Name Server The IP address for shopping.yahoo.com is Have a nice day. The IP address for shopping.yahoo.com is Have a nice day.

40 Your Workstation SHOPPING.YAHOO.COM Web Server

Copyright © 2007 Heathkit Company, Inc. All Rights Reserved PC Fundamentals End