Webmastering1-2

Counsel“Seek ye counsel of the aged for their eyes have looked on the faces of the years and their ears

have hardened to the voices of life. Even if their counsel is displeasing to you, pay heed to them.”

Kahlil Gibran (1883-1931)

Today’s Objectives

Describe the Internet and how it works

Describe TCP/IP and routing

Describe the way Internet addresses work

Describe the Domain Name System

Describe how the Internet is controlled

TEKS

126.28.2.c.1.a The student is expected to demonstrate knowledge and appropriate use of operating systems, software applications, and communication and networking components.

126.28.2.c.1.E The student is expected to use vocabulary related to web mastering and delineate between the Internet and an Intranet.

126.28.2.c.1.F The student is expected to summarize the technical needs of a World Wide Web (WWW) server including Random Access Memory (RAM), hard disk capacity, Central Processing Unit (CPU) speed, methods of connectivity, and appropriate software.

126.28.2.c.3.B The student is expected to demonstrate proper etiquette and knowledge of acceptable use policies when using networks, especially resources on the Internet and Intranet.

Vocabulary

backbone

checksum

computer network

Domain Name System

Header

Internet

Internet Corporation for Assigned Names (ICANN)

Internet Protocol (IP)

Internet Society (ISOC)

IP address

IP packet

Local Area Network

Name server

Network

Packet

Packet-switched network

Protocol

Router

Transmission Controlled Protocol (TCP)

World Wide Web Consortium (W3C)

What is the Internet?

Computer network/network - Two or more computers that are connected so that they can communicate with each other.

Examples: Printers or hard disk drives

Most important: files, information, email, or instant messaging

What is the Internet?

The Internet is a collection of computer networks that communicate with each other using a common set of rules and protocol. In order for the “network” to become part of the Internet, it must use the protocol (rules) that the Internet uses. Think of the internet as a “global network” that uses all the same “rules”.

See Figure 1-1

What is the Internet?

The Internet began as a project of the US government in the 1960’s to connect the computers of government agencies and universities.

TRIVIA question - What famous person stated that he created the internet during the 2004 presidential election?

Al Gore!

How the Internet Works

The Internet is a network known as a “packet-switched network”.

this means that data is sent through the network in packets

when 2 computers communicate over the Internet, data does not flow directly between the computers

data is broken up into “packets” and the packets travel from device to device through the network until they reach their destination

How the Internet Works

packets are reassembled on the receiving end

as packets travel, they pass from on network to another

devices called routers examine packets and decide the path they should travel

if a packet is going across the country or world, it will probably travel from one “packet” to another until it reaches large transmission lines called backbones

the packet will then jump off the backbone when it reaches a network that can link it to final destinations.

TCP / IP and Routing

a protocol called TCP / IP makes it possible for packets to travel the internet

TCP (Transmission Control Protocol) defines how data is broken down into packets at the sending end and reassembled at the receiving end

IP (Internet Protocol) defines how data is routed over the Internet

A typical packet created by TCP, called an IP Packet, is less than 1500 characters is length

TCP / IP and Routing

TCP’s job is to create a collection of information about the IP Packet called a “header”

the packet “header” contains information about the destination address and the checksum

Checksum

the checksum is just a number that allows the receiving end of the packet to determine if errors occurred in the transmission of data

TCP / IP and RoutingWhen TCP has an IP Packet ready to travel, the packet goes out on a network.

the packet starts out on a network called a LAN (Local Area Network)

when a file or message is sent over the Internet, the packets that make up the file or message may take different routes

•it is even possible that the packets could arrive at their destination in the wrong order

•it’s up to TCP to put it all back together

Tracert

Pronounced “trace route”

the tracert command is used to trace the route of packets between points on the internet

Mac Tracert

Finder > Applications > Utilities > Network Utility > Traceroute

enter a web address (www.yahoo.com etc)

check number of hops

take a picture of screen (command+shift+4) & print

make sure your name is on your tracert before you turn it in