This document discusses virtual private networks (VPNs). It defines a VPN as a network that uses the open infrastructure of the internet to transmit data between corporate sites. It describes the need for VPNs to allow remote employees, growing corporations, and developing business relations to securely access corporate databases. The document outlines the basic working of VPNs through encrypted tunnels between remote users or sites and destination security servers. It also lists different types of VPNs and the protocols and hardware used to implement VPNs.

1. VIRTUAL
PRIVATE
NETWORK
PREPARED BY:
Jigar B Navadiya
(D11CE144)

2. VIRTUAL PRIVATE NETWORK
 Definition
and introductory notes
VPN is the network which uses open
distributed infrastructure of the internet
to transmit data between corporate sites.

3. NEED FOR DEVELOPING VPN
 Remote employees interested to access
database of corporations.
 Corporate sites developing new relations.
 Increasing growth of the corporation.

4. VPN RESOLVES THE
PROBLEM
 Itprovides flexibility and scalability
 Cost advantage.
 Makes free from maintenance and training.

5. WORKING OF VPN
 STEP1…
 STEP2…
 STEP3…
 STEP4…

6. WORKING-STEP1 (cont…)
 The remote user dials into their local ISP and logs
into the ISP’s network as usual.
BACK

7. WORKING-STEP2 (cont…)
 When connectivity to the
corporate network is
desired, the user
initiates a tunnel request
to the destination
Security server
BACK

8. WORKING-STEP3 (cont…)
 The user then sends
data through the
tunnel which encrypted
by the VPN software
before being sent over
the ISP connection
BACK

9. WORKING-STEP4 (cont…)
 Thedestination Security server receives
the encrypted data and decrypts.

10. TYPES OF VPN
 VLL-Virtual leased lines.
 VPRN-virtual private routed network.
 VPDN-virtual private dial-up network.
 VPLS-virtual private LAN segments.
 Intranet VPN.
 Extranet VPN.
 Remote access VPN.

11. Virtual Private Network
VIRTUAL LEASED LINES
 Point to point link
between two CPE
 IP tunnel between
2 ISP edge
routers.
 Frames are relayed
between IP tunnels.

12. Virtual Private Network
VIRTUAL PRIVATE ROUTED
NETWORK
 Emulation of multisite
WAN using internet.
 Packet forwarding at
network layer.
 VPRN specific
forwarding table at
ISP routers that
forwards the traffic.

13. VIRTUAL PRIVATE DIAL-UP
NETWORK
 On demand tunnel between remote user and
corporate sites.
 There are possible 2 tunnels.
1… compulsory tunnel.
2… voluntary tunnel.

14. Virtual Private Network
COMPULSORY TUNNEL
 In this scenario L2TP
Access Contractor (LAC)
acting as a dial or
network access server
extends a PPP session
across a backbone using
L2TP to a remote L2TP
Network Server (LNS).
The operation of
initiating the PPP session
to the LAC is transparent
to the user.
BACK

15. Virtual Private Network
VOLUNTARY TUNNEL
 Voluntary tunnel refers
to the case where an
individual host connects
to a remote site using a
tunnel originating on the
host, with no involvement
from intermediate
network nodes. Tunnel
mechanism chosen can be
IPSec or L2TP.

16. VIRTUAL PRIVATE LAN
SEGMENTS
A Virtual Private
LAN Segment
(VPLS) is the
emulation of a LAN
segment using
internet facilities.

17. INTRANET VPN
 The branch office
scenario securely
connects two trusted
intranets within the
organization.
 Routers or firewalls
acting as gateways for
the office with vpn
capabilities can be
used to protect the
corporate traffic.

18. EXTRANET VPN
 Inthis scenario multiple supplier intranets that need
to access a common corporate network over the
Internet. Each supplier is allowed access to only a
limited set of destinations within the corporate
network.

19. REMOTE ACCESS VPN
A remote user wants to be able to communicate securely
and cost-effectively to his corporate intranet. This can
be done by use of an VPN IPSec enabled remote client
and firewall (or gateway).

20. VPN PROTOCOLS
 1. PPTP (Point-to-point tunneling
protocol)
 2. IPsec (IP security).
 3. L2TP (layer2 transmission protocol).

21. LAYER2 TRANSMISSION
PROTOCOL
 What is actually the layer two transmission
protocol ???
NEXT

22. POINT TO POINT
TUNNELING PROTOCOL
 Introduction to PPTP.
 How actually PPTP works ???
 Security provided by PPTP.
 Advantages of PPTP.
 Disadvantages of PPTP.
BACK

23. INTERNET PROTOCOL
SECURITY
 Introduction to IP security.
 Features of IP security.
 Types of IPsec protocols.
 Types of modes used in IPsec.
BACK

24. SECURITY OF VPN
 Hardware solution
 Remote access control.

25. CERTAIN H/W AND S/W
SPECIFICATIONS…
 Desktop software client for each remote
user
 Dedicated hardware such as a VPN
Concentrator or Secure
 PIX Firewall
 Dedicated VPN server for dial-up services
 NAS (Network Access Server) used by
service provider for
 remote user VPN access

26. Virtual Private Network
VPN CONCENTRATOR
 Itincorporates the
most advanced
encryption and
authentication
techniques for
Remote access
VPN.

27. Virtual Private Network
VPN-OPTIMIZED ROUTER
 VPN-optimized
routers provide
scalability, routing,
security and quality
of service.

28. Virtual Private Network
PIX FIREWALL
 Firewallcombines
dynamic network
address
translation, proxy
server, packet
filtration, firewall
and VPN
capabilities in a
single piece of
hardware.

29. Virtual Private Network
VPN/VOIP Application

30. ADVANTAGES OF VPN
 Cost saving.
 Reduces the long distance charges of
electronic transactions.
 Concrete security.

31. DISADVANTAGES OF VPN
VPNs require an in-depth understanding of public network security
issues and taking proper precautions in VPN deployment.
The availability and performance of an organization's wide-area
VPN (over the Internet in particular) depends on factors largely
outside of their control.
VPN technologies from different vendors may not work well
together due to immature standards.

32. CONCLUSION
 From this we can conclude that VPN
provides a very safe , secure and cost-
effective communication infrastructure.

33. Virtual Private Network
THANKING YOU !!!