1. Netmetric Solutions
( Meer Shahanawaz ) ( Abdullah )
VPN Definition
Virtual Private Network. A network which uses the public network to transfer
information using secure methods. For example, you could set up a VPN between
your home office and your business office using security and encryption and the
Internet as your transfer pipe.
VPN is used to make the communication between two private networks over the
Internet.
A VPN carris private traffic over a public network using advanced encryption and
tunnels to protect:
.Confentiality of Information
.integrity of data
.Authentication of users
A VPN is used to make the tunnel between two private netwoks over the
internet.
. A tunnel is a virtual point-point connection.
. The tunnel carries one protocol inside another protocol
. Encryption transforms content information into
ciphertext . Decryption restores content information from
ciphertext
Types of VPN
1.Site to Site VPN 2.Remote Access VPN
VPN with different Host
1.PC ( Host ) to PC (Host ) 2.PC (Host) to Router
3.Router to Router 4.Router to
Firewall 5.Firewall to Firewall
1.VPN used the protocols to make the tunnel , such as
PPTP Point to Point Protocol
L2TP Layer 2 Tunneling Protocol
IPSEC Internet Protocol Security
2.VPN used to make the Gateway to Gateway to communication
2. 3.VPN is used to encrypt the using some public or private key , so that only
authorized users is able to decrypt the communication.
PPTP Definition
Point-to-Point Tunneling Protocol, a new technology for creating
Virtual Private Networks (VPNs) , developed jointly by Microsoft Corporation, U.S.
Robotics, and several remote access vendor companies, known collectively as the
PPTP Forum. A VPN is a private network of computers that uses the public Internet to
connect some nodes. Because the Internet is essentially an open network, the Point-
to-Point Tunneling Protocol (PPTP) is used to ensure that messages transmitted from
one VPN node to another are secure. With PPTP, users can dial in to their corporate
network via the Internet.
L2TP Definition
Short for Layer Two (2) Tunneling Protocol, an extension to the PPP protocol that enables ISPs to operate
Virtual Private Networks (VPNs). L2TP merges the best features of two other tunneling protocols: PPTP
from Microsoft and L2F from Cisco Systems. Like PPTP, L2TP requires that the ISP's routers support the
protocol.
IP SECURITY
Short for IP Security, a set of protocols developed by the IETF to support secure exchange of packets at the
IP layer. IPsec has been deployed widely to implement Virtual Private Networks (VPNs).
3. IPsec supports two encryption modes: Transport and Tunnel. Transport mode encrypts only the data portion
(payload) of each packet, but leaves the header untouched. The more secure Tunnel mode encrypts both the
header and the payload. On the receiving side, an IPSec-compliant device decrypts each packet.
For IPsec to work, the sending and receiving devices must share a public key. This is accomplished through
a protocol known as Internet Security Association and Key Management Protocol/Oakley
(ISAKMP/Oakley), which allows the receiver to obtain a public key and authenticate the sender using
digital certificates
