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Introduction to TCP/IP, the Internet , IP Addressing , and Domain Name. Internet. The Goliath of all computer networks Links hundreds of millions of computer users throughout the world. Internet. A Network of Networks Tens of thousands of separate computer networks All interlinked.
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Introduction to TCP/IP, the Internet, IP Addressing,and Domain Name
Internet • The Goliath of all computer networks • Links hundreds of millions of computer users throughout the world
Internet • A Network of Networks • Tens of thousands of separate computer networks • All interlinked
Internet • “a loosely organized international collaboration of autonomous, interconnected networks.” • IETF (Internet Engineering Task Force)
Internet • Loosely Organized: • No single organization controls it • No control over what content or service appears • Any kind of material imaginable is present • No guarantee of information accuracy
Internet • International: • At least 192 countries represented
Internet • Collaboration: • Internet exists because of cooperation among many different organizations • Collaboration of programmers throughout the world
Internet • Interconnected • Concept of Interconnection • Using standard protocols to enable networks to communicate with each other. • Provided by TCP/IP Protocol
TCP • Transmission control protocol • Communication between applications • A communication request is sent • “full-duplex” communication • Communication line is occupied between the two computers
IP • Internet Protocol • “Connection-less” communication protocol • Messages or other data are broken up into small independent “packets” and sent between computers via the Internet • IP “routes” each packet to correct destination
IP Routers • “Routing” the packet to the correct destination, directly or via another router. • Router: responsible for right addressing • Depending on traffic volume • Errors in the network • Etc..
Connection-less analogy • Sending a long letter as a large number of small post cards RECEIVER
TCP/IP • TCP and IP working together
IP Addresses • Each computer must have an IP address before it can connect to the internet • Each IP packet must have an address before it can be sent to another computer This is an IP address: 192.68.20.50This might be the same IP address: www.fark.com
IP Address • Contains 4 numbers • Each computer must have a unique IP address • My IP Address: 120.28.219.91 • Uses 4 numbers to address a computer (between 0 and 255) • 4 numbers separated by a period
Domain name • A name is much easier to remember than a 12 digit number. • Names used for TCP/IP addresses are called domain names. • wordpress.com is a domain name. • When you address a web site, like http://www.wordpress.com, the name is translated to a number by a Domain Name Server (DNS). • DNS servers are connected to the Internet. DNS servers are responsible for translating domain names into TCP/IP addresses.
Examples of Domain Names • www.howstuffworks.com - a typical name • www.yahoo.com - the world's best-known name • www.mit.edu - a popular EDU name • encarta.msn.com - a Web server that does not start with www • www.bbc.co.uk - a name using four parts rather than three • ftp.microsoft.com - an FTP server rather than a Web server
Parts of a Domain Name • Top-level domain or First-level domain • COM, EDU, GOV, MIL, NET, ORG, INT • Unique two letter combination for every country • Second-level domains • e.g. for COM first level domain: • Howstuffworks • Yahoo • msn • Microsoft, etc..
Parts of a Domain Name • Third-level domain: • bbc.co.uk • Up to 127 levels are possible • Host name • Specifies name of a specific machine (with a specific IP address) in a domain. • E.g. www or encarta
Domain names need to be unique • Network Solutions • Company responsible for maintaining a list of unique COM domain names • Register a Domain Name • Goes through several registrars who work with Network Solutions • Keeps the whois database. Info of owners and name servers for each domain.
SEATWORK • What is the Goliath of All Computer Networks? • What does TCP mean? What does IP mean? • Each of the four numbers in an IP address is from the range of numbers between __ and __, inclusive • What is another name for First-level domain? • What countries do these first-level domains represent? • .tw, .ph, .mx, .dk