Internet Basics 2K A presentation by Patrick Douglas Crispen NetSquirrel.com.

transcript

Internet Basics 2KInternet Basics 2K

A presentation by

Patrick Douglas CrispenNetSquirrel.com

For More InformationFor More Information

http://netsquirrel.com/

Information about the Squirrel HuntInformation about TOURBUSA copy of this presentation

What IS the Internet?What IS the Internet?

“A network of networks based on the TCP/IP protocols, a community of people who use and develop these protocols, and a collection of resources that can be reached from those networks.”

-- Krol & Hoffman

Frequently Asked Frequently Asked QuestionsQuestions

• What IS the Internet (and what IS the World Wide Web)?

• How do the Internet and the Web work?

• What can I do on the Internet?• How do Internet addresses work?

Our GoalsOur Goals

• To answer some of the Net’s biggest Frequently Asked Questions (FAQs)

• To show you how the Internet really works

• To teach you how to read Internet addresses

• To do all of this in ENGLISH!!

GermanyGermany

• Self-sufficient cities

• The military needs 2 things to survive:– Supplies– Intelligence

WW2 GermanyWW2 Germany• Autobahn• Secure supply

lines• What happens to

German supply if a city is “lost?”

• Where is the Autobahn’s Headquarters?

I LIKE IKE!I LIKE IKE!

EISENHOWERINTERSTATESYSTEM

TEXAS’ Interstate TEXAS’ Interstate SystemSystem

• Safe supply lines

• Unlimited alternate routes

• Personal use

US Military US Military IntelligenceIntelligence

• Needed a way to hook up all of the mainframes in the USA

• Needed a system that could withstand a direct nuclear attack (well, not really)

• Needed a system without a central command

TEXAS and the TEXAS and the Internet?Internet?

• Cities = LANs or ISPs

• Interstates = Communications lines

• States = Regional Networks

IP PacketsIP Packets

• Everything that is sent over the Internet is sent in an IP Packet.

• IP Packets can contain anything

IP Packet RoutingIP Packet Routing

• TCP (Transmission Control Protocol)– Universal “rules”

of the Road

• IP (Internet Protocol) Addresses– 255.255.255.255

Domain Name System Domain Name System (DNS)(DNS)

Converts “English” nameswww.whitehouse.gov

into “Machine” (IP) names198.137.241.30

• Using your browser, you type in a URLhttp://www.whitehouse.gov/

• You “access” or “request” a Web page

• Your ISP “resolves” address– www.whitehouse.g

ov– 198.137.241.30

• Your ISP then puts your request into an IP packet (or a bunch of packets)

• The IP address is spray painted on the front windshield of the IP packet

• Your ISP ships the packet(s) to their router

• The router ships the packet(s) to the next “city”

Questions Routers Questions Routers “Ask”“Ask”

• Is this packet broken?

• Is this packet for me?

• In which general direction should this packet be sent?

At the White HouseAt the White House

• Mr. Bill’s Web Server receives your request

• It sends you the Web page you requested (including all of the text and multimedia)

• All of this is broken into a bunch of IP packets

• Mr. Bill’s ISP ships the packet(s) to his router

• The router ships the packet(s) to the next “city”

• THE CONNECTION IS DROPPED!

• The packets bounce through cyberspace

• Finally, the packets get to you, are put back in order, and the Web page appears

TEXAS and the TEXAS and the Internet?Internet?

• Each and every “intersection” (or “city”) is a router.

Pop QuizPop Quiz

• Is communication on the Internet (electronic mail, file transfers, etc.) instantaneous?

• Is the Internet now, or has it EVER been, free?

Two More QuestionsTwo More Questions

• Who owns the Internet?

• Who runs the Internet?– System of

networks (“backbone”)

What can I do on the What can I do on the Internet?Internet?

• Communicate• Login• Download• Publish• PLAY!

The Internet v. The The Internet v. The WebWeb

• What is the difference between the Internet and the World Wide Web?

• The Internet is ALL of the computers and ALL of the information available

• The World Wide Web is a subset of the Internet that contains hypermedia and is accessible through a Web browser.

How can I get on the How can I get on the Internet?Internet?

• Bulletin Board Service (BBS)• Commercial Online Service

– AOL / CompuServe– MSN

• Internet Service Provider (ISP)• Work/School

ModemsModems

• Converts digital signals to analog signals

• Modem at the other end turns the analog signal back into a digital signal.

Modem SpeedsModem SpeedsThe InternetBaud Speed Transfer Rate14.4 14,400 bps 1.76 Kb per second28.8 28,800 bps 3.56 Kb per second56 K 56,600 bps (*) 6.47 Kb per secondT1 1.5 million bps 183 Kb per secondT3 45 million bps 5.36 Mb per second

Modem SpeedsModem SpeedsThe InternetBaud Speed Transfer Rate14.4 14,400 bps 1.76 Kb per second

Internet2 (I2)Baud Speed Transfer RateOC-3 155 Mbps 18.54 Mb per secondOC-12 622 Mbps 74.16 Mb per secondOC-48 2.48 Gbps 295.64 Mb per second

Internet AddressesInternet Addresses

• Machine addresses (IP or DNS)

• “Personal” addresses (e-mail)

• Resource addresses (Web pages, gopher directories, etc.).

Machine AddressesMachine Addresses

• IP Addresses– 255.255.255.255

• DNS Addresses– whitehouse.gov– www.yahoo.com– ua1vm.ua.edu

crispen@netsquirrel.com

E-Mail AddressesE-Mail Addresses

• The world of e-mail is bigger than the Internet

• E-mail goes to a person, not just a machine

Parts of an E-mail Parts of an E-mail AddressAddress

• USERID– Name– Number– Combination of

• The “at” sign– Above the number

2 on your keyboard

• The address of the user’s mail server– IP Address 207.158.244.32

– DNS Address netsquirrel.com

Resource AddressesResource Addresses

Uniform Resource Locators (URLs)protocol://machine.address/dir/file

The /dir/file/ stuff may be optionalThe protocol, the ://, and the machine

address are REQUIRED

http Web pagesftp File Transfer Protocolgopher Gopher Directories

http://www.yahoo.com/

ftp://risc.ua.edu/pub/roadmap/

gopher://boombox.micro.umn.edu/

REMEMBERREMEMBERE-mail addresses have @ symbols

URLs have ://

The machine address can be either a DNS Address or an IP Address

http://www.yahoo.com/

• Machine Addresses– DNS or IP address

• Personal Addresses– userid@machine.address

• Resource Addresses– protocol://machine.address/dir/file

• Machine Addresses– whitehouse.gov– 198.137.241.30

• Personal Addresses– president@whitehouse.gov

• Resource Addresses– http://www.whitehouse.gov/

Machine Addresses -- Machine Addresses -- DomainsDomains

EDU EducationMIL MilitaryGOV Non-Military

Government Sites

COM Commercial

Organizations

crispen@netsquirrel.comhttp://www.yahoo.com/

Machine Addresses - Machine Addresses - DomainsDomains

NET Network Sites

ORG Other

OrganizationsUK United

KingdomCA CanadaAU Australia

crispen@netsquirrel.comhttp://www.yahoo.com/

Reading Internet Reading Internet AddressesAddresses

73624.3363@compuserve.com

pbs.org

c523637@mizzou1.bitnet

http://housing.msstate.edu/

141.211.83.37

crispen@foxy.boeing.com

president@whitehouse.gov

www.mcgill.ca

wolfe@alhrg.wpafb.af.mil

204.162.80.181

postmaster@204.162.80.181

http://204.162.80.181/

http://cnet.com/

pcrispe1@ua1vm.ua.edu

Finding an E-mail Finding an E-mail addressaddress

• Search engines– WHOIS– Four-11

• The best way to find someone’s e-mail address is to call them on the telephone and ask them for it.

Crispen’s Five Crispen’s Five Antivirus RulesAntivirus Rules

• Buy a commercial antivirus program• Update your definitions weekly• Never double-click on a file, especially

an email attachment, without first virus checking it

• Turn on Macro Virus Protection in Word

• If you don’t know what an email attachment is, delete it.