Internet Intranet Extranet2

7/31/2019 Internet Intranet Extranet2

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Presentation by :-

A.JUDITH AROCKIA

GLADIES(M.E CSE)


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It is a Global network of computers,

(servers or clients).

to exchange information.

It is a "network of networks" that includes millionsof private and public, academic, business, andgovernment networks (local or Global),

linked by copper wires, wireless connections, andother technologies.


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What is the Internet?

Figure 7.1 The Internet connects mi


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Computer

In addition to a modem, you need a client capable

of handling multiple data types.

Software

Twotypes ofsoftwares required to enable yourPC as an Internet PC.

Communication softwaretoestablish connection

Client software forbrowsing, e-mail, news.

these softwares are provided with windows itself.


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Download programs and files

E-Mail

Voice and Video Conferencing

E-Commerce

File Sharing

Information browsing

Search the web addresses for access throughsearch engine

Chatting and many more


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Theft of personal information such as name, address, creditcard number etc.

Virus threats nothing but a program which disrupts the normalfunctioning of your system.

Spamming refers to receiving unwanted e-mails in bulk, whichprovide no purpose and needlessly obstruct the entire system.

Pornography This is perhaps the biggest threat related tochildrens healthy mental life. A very serious issue concerning

the Internet.

Though, internet can also create havoc, destructionand its misuse can be very fatal,

the advantagesof it outweigh its disadvantages.


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The World Wide Web

Hypertext transfer protocol (HTTP)

The protocol that determines how data in files(text, images, animation, or sound) should be

coded, transferred, and viewed on the Internet.

Browsers

Special software designed to search the Web forspecific sites and retrieve information (text,

pictures, sound, and animation.)


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The World Wide Web

Figure 7.6 How a CGI works


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The World Wide Web

Cookies

Small file a Web site places on a visitors hard disk so

the site can remember something about the surfer later

Creating Your Own Web Pages

Search the Web for HTML tutorials

View and study the source document of a Web page


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A within-organization computer network that

uses Internet technologies to communicate

Internal company network that uses Internet

standards (HTML, HTTP & TCP/IP protocols) &

software.

Accessed only by authorized persons, especially

members or employees of the organization


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Two levels of Security required:

Internal

It can be imposed by Public Key Security &

Encryption Key.

External

Through Firewall.


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Security device located between firms internal

network (intranet) & external network (internet).

Regulates access into & out of a companys network

based on a set of rules.

Note : needs to be upgraded from time to time to check latest

potential security problems.


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Sharing of company policies/rules & regulations

Access employee database

Distribution of circulars/Office Orders

Access product & customer data

Sharing of information of common interest

Launching of personal/departmental home pages Submission of reports

Corporate telephone directories
http://www.cio.com/WebMaster/strategy/http://www.cio.com/WebMaster/strategy/


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Information overload lowers productivity

True purpose of the Intranet is unknown to manyemployees/departments

Hidden or unknown complexity and costs

Productivity

problem

Unauthorized access

Abuse of access

Denial of service

Security

problem

A company may not have person to update their

Fear of sharing information and the loss of control Limited bandwidth for the business

Management

problem Intranet on a routine basis


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Extranet is an Intranet for outside authorized users

using same internet technology.

Inter-organizational information system.

enable outsiders to work together with companys

employees.

open to selected suppliers, customers & other business

partners


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Dealers/distributors have access to

product files such as :-

1. product specification,

2. pictures,

3. images, etc.

to answer the queries of the customer.


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Some basic infrastructure components suchas the internet Including :-

TCP/IP protocols,

E-mail,

Web-browsers,

External business partners & Tele-commuting employees place order,

check status & send E-mail.


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Improved quality.

lower travel costs.

lower administrative & other overhead costs.

reduction in paperwork.

delivery of accurate information on time.

improved customer service.

better communication.

overall improvement in businesseffectiveness.


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The suppliers & customer who dont

have technical knowledge feel problem.

Faceless contact.

Information can be misused by other competitors.

Fraud may be possible.

Technical Employees are required.


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Clients, partners, customersExtranet


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Introduction: What is a VPN?

Virtual

Private

Network


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Introduction to VPN


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Introduction to VPN

Four Categories:

Trusted VPN Secure VPN

Hybrid VPN

Provider-provisioned VPN


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VPNTopology: Types of VPNs

Remote access VPN

Intranet VPN Extranet VPN


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VPN Topology: Remote Access

VPN


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VPN Topology: Intranet VPN


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VPN Topology: Extranet VPN


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VPN Topology: Advantages and

Disadvantages of VPN

Advantages:

Greater scalability Easy to add/remove users

Reduced long-distance telecommunications costs

Mobility

Security


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VPN Topology: Advantages and

Disadvantages of VPN

Disadvantages

Lack of standards

Understanding of security issues

Unpredictable Internet traffic

Difficult to accommodate products from different

vendors


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VPN Components

Protocols

Security Appliances


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VPN Components: Protocols

IP Security (IPSec)

Transport mode

Tunnel mode

Point-to-Point Tunneling Protocol (PPTP)

Voluntary tunneling method

Uses PPP (Point-to-Point Protocol)


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VPN Components: Protocols

Layer 2 Tunneling Protocol (L2TP)

Exists at the data link layer of OSI

Composed from PPTP and L2F (Layer 2

Forwarding)

Compulsory tunneling method


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Example of packet encapsulation


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VPN Components: Security

Encryption

Technique for scrambling and unscrambling

information

Unscramble called clear-text

Scrambled information cipher-text


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Keys

Secret code that the encryption algorithm uses to

create a unique version of cipher-text

8-bits keys = 256 combinations or two to the eighth

power

16-bits keys = 65,536 combinations or two to the 16th

power 56-bits keys = 72,057,594,037,927,900 or two to the

56th power

168-bits keys


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Authentication

Determine if the sender is the authorized person

and if the data has been redirect or corrupted

User/System Authentication

Data Authentication


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VPN Components: Appliances

Intrusion detection firewalls

Monitors traffic crossing network parameters and

protects enterprises from unauthorized access

Packet-level firewall checks source and

destination

Application-level firewall acts as a host computer

between the organizations network and the

Internet


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VPN Productivity and Cost

Benefits: Benefits

Extends geographic connectivity

Boosts employee productivity Improves Internet security

Scales easily


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VPN Productivity and Cost

Benefit: Costs

Costs associated with implementing VPN

In House implementation

Outsourced implementation

Middle Ground implementation


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Future of VPN

VPN popularity

Companies choosing VPN

Cost efficient?

New way of communicating?


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Network

Computer networkA combination of computers connected

through transmission media. LAN (Local Area Network)

MAN (Metropolitan Area Network)

WAN (Wide Area Network)

Internetwork(e.g. Internet)Networks can be connected using connectingdevice.


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Figure 6-3

Categories of networks


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LAN (Local Area Network)

Allow resource sharing between computers.

Computers Peripheral devices

Transmission medium (e.g. cable)

3 types of topology

Bus topology

Star topology

Ring topology


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Figure 6-4LANs

Hub a device that facilitates

connection

LAN acts logically like a bus.

Star

the dominant topology

today.


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Figure 6-5

MAN


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MAN (Metropolitan Area

Network)

Uses services provided by a network service

provider. (Tel. Company)

Individual users computers

Organizations LANs

Many Tel. Company provide a popular MANservice called SMDS(Switched Multimegabit Data Services)

Prior to SMDS's arrival in 1995,

the only way to connect LANs was through

a dedicated private line.


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Figure 6-6

WAN


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WAN (Wide Area Network)

The connection ofindividual computers or

LANs over a large area (country, world).

User using a telephone line to connect to an

ISP (Internet Service Provider) is using a

WAN. Negotiates fee

ISP

Tel. company


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Thank You

Internet Intranet Extranet2

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