Virtual private networks (VPNs) allow employees to securely access a company's intranet from remote locations over the public Internet. VPNs use encryption and tunneling protocols to create a private network across a public network like the Internet. This allows employees to access the company network from anywhere while also saving costs compared to traditional private networks by reducing equipment and maintenance expenses. VPNs authenticate users, control access, ensure confidentiality of data during transmission, and verify data integrity using encryption, digital signatures, and tunneling protocols like IPsec, L2TP, and PPTP. While VPNs provide advantages such as lower costs and remote access, they also have disadvantages like dependence on public networks outside the company's control and potential issues with

1. VIRTUAL PRIVATEVIRTUAL PRIVATE
NETWORKS (VPN)NETWORKS (VPN)
BY:BY:
JAYDEEP GHAGHADAJAYDEEP GHAGHADA
146020307515146020307515

2. Traditional ConnectivityTraditional Connectivity
[From Gartner Consulting][From Gartner Consulting]

3. What is VPN?What is VPN?
Virtual Private Network is a type of privateVirtual Private Network is a type of private
network that uses public telecommunication,network that uses public telecommunication,
such as the Internet, instead of leased lines tosuch as the Internet, instead of leased lines to
communicate.communicate.
Became popular as more employees worked inBecame popular as more employees worked in
remote locations.remote locations.

4. How are VPN better than PrivateHow are VPN better than Private
Networks.Networks.
Employees can access the network (Intranet)Employees can access the network (Intranet)
from remote locations.from remote locations.
Secured networks.Secured networks.
The Internet is used as the backbone for VPNsThe Internet is used as the backbone for VPNs
Saves cost tremendously from reduction ofSaves cost tremendously from reduction of
equipment and maintenance costs.equipment and maintenance costs.

5. Brief Overview of How it WorksBrief Overview of How it Works
Two connections – one is made to theTwo connections – one is made to the
Internet and the second is made to theInternet and the second is made to the
VPN.VPN.
Datagrams – contains data, destinationDatagrams – contains data, destination
and source information.and source information.
Firewalls – VPNs allow authorized usersFirewalls – VPNs allow authorized users
to pass through the firewalls.to pass through the firewalls.
Protocols – protocols create the VPNProtocols – protocols create the VPN
tunnels.tunnels.

6. Four Critical FunctionsFour Critical Functions
AuthenticationAuthentication – validates that the data was– validates that the data was
sent from the sender.sent from the sender.
Access controlAccess control – limiting unauthorized users– limiting unauthorized users
from accessing the network.from accessing the network.
ConfidentialityConfidentiality – preventing the data to be– preventing the data to be
read or copied as the data is beingread or copied as the data is being
transported.transported.
Data IntegrityData Integrity – ensuring that the data has– ensuring that the data has
not been alterednot been altered

7. EncryptionEncryption
Encryption -- is a method of “scrambling”Encryption -- is a method of “scrambling”
data before transmitting it onto thedata before transmitting it onto the
Internet.Internet.
Public Key Encryption TechniquePublic Key Encryption Technique
Digital signature – for authenticationDigital signature – for authentication

8. TunnelingTunneling
A virtual point-to-point connectionA virtual point-to-point connection
made through a public network. It transportsmade through a public network. It transports
encapsulated datagrams.encapsulated datagrams.
Encrypted Inner Datagram
Datagram Header Outer Datagram Data Area
Original Datagram
Data Encapsulation [From Comer]
Two types of end points:
 Remote Access
 Site-to-Site

9. Three Protocols used in VPNThree Protocols used in VPN
PPTP -- Point-to-Point Tunneling ProtocolPPTP -- Point-to-Point Tunneling Protocol
L2TP -- Layer 2 Tunneling ProtocolL2TP -- Layer 2 Tunneling Protocol
IPsec -- Internet Protocol SecurityIPsec -- Internet Protocol Security

10. Types of VPNTypes of VPN
3 Types3 Types
Intranet – Within an organizationIntranet – Within an organization
Extranet – Outside an organizationExtranet – Outside an organization
Remote Access – Employee to BusinessRemote Access – Employee to Business

11. Virtual Private Networks (VPN)
Basic Architecture

12.  Eliminating the need for expensive long-distanceEliminating the need for expensive long-distance
leased linesleased lines
 Reducing the long-distance telephone chargesReducing the long-distance telephone charges
for remote access.for remote access.
 Transferring the support burden to the serviceTransferring the support burden to the service
providersproviders
 Operational costsOperational costs
Advantages:Advantages:

13. VPNs require an in-depth understanding ofVPNs require an in-depth understanding of
public network security issues and properpublic network security issues and proper
deployment of precautionsdeployment of precautions
Availability and performance depends on factorsAvailability and performance depends on factors
largely outside of their controllargely outside of their control
Immature standardsImmature standards
VPNs need to accommodate protocols otherVPNs need to accommodate protocols other
than IP and existing internal network technologythan IP and existing internal network technology
DisadvantagesDisadvantages

14. THANK YOUTHANK YOU