Virtual private networks (VPNs) allow users to securely access a private network over a public network like the Internet. VPNs use tunneling, encryption, and authentication to provide security. Common VPN protocols include PPTP, L2TP, and IPsec. VPNs allow remote access for users and can connect multiple office sites through site-to-site VPNs. VPNs provide benefits like security, reliability, cost savings, and ability to connect globally but can have lower bandwidth and inconsistent performance compared to dedicated connections.

1. Presented by:
Debasis Chowdhury – 10208016
Md. Shariar Islam – 10208026
Antara Chowdhury – 10208036
University of Asia Pacific

2.  A technology that creates a network that is
physically public, but virtually private.

3. Leased lines
Leased lines
Leased lines
Leased
lines

4. Virtual Private Networks (VPN)
Basic Architecture

5.  VIRTUAL .
 PRIVATE .
 NETWORK .

6. TUNNELING.
ENCRYPTION.
ENCAPSULATION.
AUTHENTICATION.
FIREWALL.

7. •Tunneling is the process of placing an entire packet within another
packet before it's transported over the Internet.
• That outer packet protects the contents from public view and
ensures that the packet moves within a virtual tunnel.

9.  Point-to-Point Tunneling Protocol (PPTP)
 Layer Two Tunneling Protocol (L2TP)
 Internet Protocol Security (IPsec)

10. Encryption is the process of encoding data so
that only a computer with the right decoder
will be able to read and use it.
 Used to convert data to a secret code for
transmission over an trusted network
Encryption
Algorithm
“The cow jumped
over the moon”
“4hsd4e3mjvd3sd
a1d38esdf2w4d”
Clear TextClear Text Encrypted TextEncrypted Text

11.  For data encapsulation, VPN relies on either
of the following technologies like GRE , IPSec,
L2F,PPTP and L2TP .
 In which IPsec and PPTP are more popular.

13.  Authentication process determine if the
sender is the authorized person and if the
data has been redirect or corrupted .
 There are 2 levels of Authentication.
 Computer-Level Authentication
 User-level Authentication

14.  Firewall provides network security and business
continuity .
 It prevents attacks, and secures your data
communications with multiple parallel Virtual Private
Network (VPN) connections.
 There are two approaches to using a firewall with a
VPN server:
 VPN server in front of the firewall..
 VPN server behind the firewall..

17.  All traffic on the secure VPN must be
encrypted and authenticated.
 The security properties of the VPN must be
agreed to by all parties in the VPN.
 No one outside the VPN can affect the
security properties of the VPN.

18.  Remote access VPN
 Site to Site VPN

19.  Provides access to
internal corporate
network over the
Internet.
 Reduces long distance,
modem bank, and
technical support
costs.
InternetInternet
Corporate
Site

20.  Connects multiple
offices over Internet
 Reduces dependencies
on frame relay and
leased lines InternetInternet
Branch
Office
Corporate
Site

21.  Site-to-Site VPN
 Extranet VPN
▪ Provides business
partners access to critical
information (leads, sales
tools, etc)
▪ Reduces transaction and
operational costs
Corporate
Site
InternetInternet
Partner #1
Partner #2

22.  Site-to-Site VPN
 Intranet VPN:
Links corporate
headquarters, remote
offices, and branch offices
over a shared
infrastructure using
dedicated connections.
InternetInternet
LAN
clients
Database
Server
LAN clients with
sensitive data

23.  Security
 Reliability
 Cost Savings
 Expand Globally
 Easier
 No single point of failure
 Easier Network Management

24.  Lower bandwidth available compared
to dial-in line
 Inconsistent remote access
performance due to changes in Internet
connectivity
 No entrance into the network if the
Internet connection is broken