2. A VPN, or Virtual Private Network, allows you to
create a secure connection to another network
over the Internet. VPNs can be used to access
region-restricted websites, shield your browsing
activity from prying eyes on public Wi-Fi, and
more
What’s VPN???
3. Why we use or need VPN???
It secures your computer’s
internet connection to
guarantee that all of the data
you’re sending and receiving
is encrypted and secured
from prying eyes.
The most important thing
you need to know about a
VPN:
5. The origin of VPN
The word VPN originates from three words i.e.
Virtual: Virtual means not real or in a different state of being. In a VPN, private communication between
two or more devices is achieved. Therefore, the communication is virtually but not physically there.
Private: Private means to keep something a secret from the general public. Although those two devices are
communicating with each other in a public environment, there is no third party who can interrupt this
communication or receive any data that is exchanged between them.
Network: A network consists of two or more devices that can freely and electronically communicate with
each other via cables and wire. A VPN is a network. It can transmit information over long distances
effectively and efficiently.
6. User Authentication : VPN must be able to verify user authentication and allow only authorized
users to access the network
Requirement VPN:
Address Management : Assign addresses to clients and ensure that private addresses are kept private on the
VPN.
Multi-protocol Support : The VPN technology must support commons protocols on the Internet such as IP,
IPX etc
Data Encryption : Encrypt and decrypt the data to ensure that others on the not have access to the data
Key Management : Keys must be generated and refreshed for encryption at the server and the client. Note
that keys are required for encryption
8. The Intranet VPN
Intranet VPNs link corporate
headquarters, remote offices, and branch
offices over a shared infrastructure using
dedicated connections. The VPN typically
is an alternative to a leased line. It
provides the benefit of extended
connectivity and lower cost.
9. The Extranet VPN
Extranet VPNs link customers,
suppliers, partners, or
communities of interest to a
corporate intranet over a shared
infrastructure using dedicated
connections. In this example,
the VPN is often an alternative to
fax, snail mail, or EDI. The
extranet VPN facilitates e-
commerce
10. Remote Access VPN
A remote-access VPN allows
individual users to establish secure
connections with a remote computer
network. Those users can access the
secure resources on that network as if
they were directly plugged in to the
network's servers. An example of a
company that needs a remote-access
VPN is a large firm with hundreds of
salespeople in the field. Another name
for this type of VPN is virtual private
dial-up network (VPDN),
acknowledging that in its earliest form,
a remote-access VPN required dialing
in to a server using an analog
telephone system.
11. Tunneling
Tunnelling involves the encapsulation,
transmission and de-capsulation of data packets.
The data is encapsulated with additional headers.
The additional headers provide routing
information for encapsulated data to be routed
between the end points of a tunnel.
Requires 3 protocols
1) Carrier, Default network protocol
2) Passenger ,Original data
3) Encapsulation GRE, IPsec , PPTP etc.
12. Tunnel Types
Voluntary
VPN request is initiated by the client.
The client remains the end point.
Compulsory
VPN access server creates a compulsory tunnel for the client.
In this case, the dial-up access server between the user’s computer and the tunnel
server is the tunnel end point that acts as a client .
Voluntary tunneling is used in most applications.
13. Advantages :
Greater scalability
Easy to add/remove users
Reduced long-distance
telecommunications costs
Mobility
Security
Disadvantages :
Lack of standards
Understanding of security issues
Unpredictable Internet traffic
Difficult to accommodate
products from different vendors
Advantages and Disadvantages of VPN :
