Chapter Overview
What is the Internet?– Overview of various Internet Services
How does the Internet work? The World Wide Web Security and the Internet Intranets and Extranets Future directions of the Internet
“The Internet is one of the rare, if not unique, instances where ‘hype’ is accompanied by understatement, not overstatement…I don’t think we know what has hit us.”
Nicholas Negroponte, Director, MIT Media Lab
What is the Internet?
Two or more networks joined together (i) Worldwide group of connected networks
that allow public access to information and services (I)
No central governing body Estimated 2.8 billion users
Roughly 39% of the world population
Brief History of the Internet
1969 - Network of four University computers (ARPANET)
1984 - Domain Name System introduced 1986 - NSFnet connects to ARPANET 1988 - Internet WORM affects 6,000 hosts 1991 - Gopher and WWW released 1993 - Mosaic is released Various organizations help define standards
Internet Services
World Wide Web E-mail FTP (Archie) Telnet Chat Rooms (IRC) Usenet Gopher (Veronica and Jughead)
How does the Internet work?
Clients Web Servers (www.netcraft.com) Packets Routers Packet Switching (TCP / IP) Backbone Network Access Point (NAP)
Internet Addresses
IP (Internet protocol) address– 128.205.2.235 (IPv4)– 2002:80CD:2EB:0:0:0:0:0 (IPv6)
Domain name– mgt.buffalo.edu
Domain Name System (DNS) Domain name servers
nslookup <hostname> in Windowshost <hostname> in UNIX
World Wide WebWorld Wide WebWorld Wide WebWorld Wide Web
CERN – Where the Web was born– home.web.cern.ch/topics/birth-web
– Tim Berners-Lee – Hyperlinked documents– Defined URL’s, HTML, and HTTP– Designed for collaborative research
Anatomy of a Web PageAnatomy of a Web PageAnatomy of a Web PageAnatomy of a Web Page
Uniform Resource Locator (URL)
Hypertext transfer protocol (http://)
Hypertext markup language (HTML)
Hyperlinks
Web Page Do’s and Don’tsWeb Page Do’s and Don’tsWeb Page Do’s and Don’tsWeb Page Do’s and Don’ts
Keep your pages small Limit graphics on pages to keep them
“light” Reuse graphics and avoid animations Balance images and text Test...test...test… Know your customer
Security on the InternetSecurity on the InternetSecurity on the InternetSecurity on the Internet
CERT - www.cert.org
– 1988 1 advisory and 6 incidents
– 2003 28 advisories, 137,529 incidents and
3,784 vulnerabilities
Hackers, Phishing, Denial of Service,
Worms, Viruses, Social Engineering,
Fraud, Identity Theft
Security SolutionsSecurity SolutionsSecurity SolutionsSecurity Solutions
Authentication / Authorization
Firewalls
Intrusion Detection Systems
Data Encryption
Secure Sockets Layer (SSL)
Security Awareness Training & Education
Intranets (B2E)Intranets (B2E)Intranets (B2E)Intranets (B2E)
“Private corporate network that uses Internet technology and is designed to meet the needs of employees”
Extranets (B2B)Extranets (B2B)Extranets (B2B)Extranets (B2B)
“Private corporate network designed to meet the needs of external parties such as suppliers, customers, and stockholders”
The Internet and BusinessThe Internet and BusinessThe Internet and BusinessThe Internet and Business
24 / 7 access Global presence Lower marketing costs Two-way communications Lower product display and storage costs Lower salesperson costs Electronic commerce opportunities