Pindaro Demertzoglou Lally 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. 2

IP Addresses Static IP address – permanently assigned IP address Dynamic IP address – temporarily assigned An IP address is a series of numbers, such as It is separated into four sections by periods Each section’s number cannot exceed 255

Domain Names People 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 lowercase Key component of URLs and addresses Lallylab2.mgmt.rpi.edu/mis lallylab2.mgmt.rpi.edu is the domain name ( )

Registering a Domain Name

TCP - IP Transmission Control Protocol (TCP) Breaks messages into packets and specifically into octets (eight bits) reliably and in the correct order. Internet Protocol Addresses packets from one computer to another.

Internet Statistics World Statistics Language Statistics Top 20 Countries

Internet Protocols

WWW List of www browsers Web Server Statistics

FTP – File Transfer Protocol Basic Facts FTP Clients

Servers List of servers SMTP – POP protocols

12 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 Internet 13 Cable Internet Service Cable Internet service distributes always-on broadband Internet access over the same infrastructure that offers cable television service

Internet Connections

15 Internet Security Intrusion Attempts Securing Ports Routers and NAT Virtual Private Networks

16 Intrusion Attempts An 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: A list of ports: DP_port_numbers DP_port_numbers

Port Scanners Software used by network administrators and hackers to identify open ports of computers in the network. canner.php canner.php

Intranets What is an Intranet Technical Advantages Business Advantages Service Platforms Intranets in today’s economy Measuring Intranet ROI

What is an Intranet It is a private information system Built on Internet technologies Client-server system architecture Based usually on three-tier system It is not a telecommunications network

Technical Advantages Easy to learn Fast to build Easy to deploy Easy to maintain Easy to update Easy to personalize

Business Advantages Cheaper than deploying traditional systems Shrinks distances Adds to the company’s business intelligence

Business Advantages Can 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 Platform Mail server Web server Indexing server Transaction server DB server Data Warehouse server

The role of extranets What is an extranet? It is an extension of the Intranet. It includes entities from the external environment of the company.