Pindaro DemertzoglouLally School of M&T

Internet-Intranets-Extranets

How the Internet Started The ARPANET, created in 1969,

connected computers at UCLA, Stanford, University of Utah, and University of California at Santa Barbara.

Then, the military liked the idea for distributed decision centers.

Today, the Internet connects computers all over the globe and supplies information to people of all ages and interests.

The Internet is not owned or operated by any single corporation or government.

The Internet is based on a network of networks.

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IP AddressesStatic IP address – permanently assigned

IP address

Dynamic IP address – temporarily assigned

An IP address is a series of numbers, such as 204.127.129.001It is separated into four sections by

periodsEach section’s number cannot exceed 255

Domain NamesPeople find it difficult to remember long

strings of numbers, so host computers also have names called domain names

Domain name – “fully qualified domain name” (FQDN), usually typed in all lowercaseKey component of URLs and e-mail

addressesLallylab2.mgmt.rpi.edu/mis

lallylab2.mgmt.rpi.edu is the domain name (128.113.9.243)

Registering a Domain Namehttp://www.google.com/a/cpanel/domain/ne

w

http://www.register.com/

http://smallbusiness.yahoo.com/domains/

TCP - IPTransmission Control Protocol (TCP)

Breaks messages into packets and specifically into octets (eight bits) reliably and in the correct order.

Internet ProtocolAddresses packets from one computer to

another.

Internet StatisticsWorld Statistics

http://www.internetworldstats.com/stats.htm

Language Statisticshttp://www.internetworldstats.com/stats7.ht

m

Top 20 Countrieshttp://www.internetworldstats.com/

top20.htm

Internet Protocols

WWWList of www browsers

http://en.wikipedia.org/wiki/List_of_web_browsers

Web Server Statisticshttp://news.netcraft.com/archives/

web_server_survey.html

FTP – File Transfer ProtocolBasic Facts

http://en.wikipedia.org/wiki/File_Transfer_Protocol#Software

FTP Clientshttp://en.wikipedia.org/wiki/

Comparison_of_FTP_clients

Email ServersList of email servers

http://en.wikipedia.org/wiki/Comparison_of_mail_servers

SMTP – POP protocols

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DSL, ISDN, and Dedicated Lines

DSL is a high-speed, digital, always-on Internet access technology that runs over standard phone lines.

Chapter 6: The Internet13

Cable Internet ServiceCable Internet service distributes always-on

broadband Internet access over the same infrastructure that offers cable television service

Internet Connections

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Internet SecurityIntrusion AttemptsSecuring PortsRouters and NATVirtual Private Networks

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Intrusion AttemptsAn intrusion is any access to data or

programs by hackers, criminals, or other unauthorized persons

Looking for open ports is one of the most common ways of gaining unauthorized access to a network-based computer.

A port is associated with an IP address of the host computer.

A web port:http://lallylab2.mgmt.rpi.edu:80/mis/

A list of ports:http://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers

Port ScannersSoftware used by network administrators

and hackers to identify open ports of computers in the network.

http://www.radmin.com/products/previousversions/portscanner.php

IntranetsWhat is an IntranetTechnical AdvantagesBusiness AdvantagesService PlatformsIntranets in today’s economyMeasuring Intranet ROI

What is an IntranetIt is a private information systemBuilt on Internet technologiesClient-server system architectureBased usually on three-tier systemIt is not a telecommunications network

Technical AdvantagesEasy to learnFast to buildEasy to deployEasy to maintainEasy to updateEasy to personalize

Business AdvantagesCheaper than deploying traditional systemsShrinks distancesAdds to the company’s business

intelligence

Business AdvantagesCan link to other sources of information.Adds “time” to a company

Through document sharing (text, drawings).Online collaboration

Cheaper than deploying traditional systems.

Shrinks distances.Adds to the company’s business

intelligence.

Intranet Services PlatformMail serverWeb serverIndexing serverTransaction serverDB serverData Warehouse server

The role of extranetsWhat is an extranet?It is an extension of the Intranet.It includes entities from the external

environment of the company.