1. Netmetric Solutions ( Meer Shahanawaz ) ( Abdullah ) VPN DefinitionVirtual Private Network. A network which uses the public network to transferinformation using secure methods. For example, you could set up a VPN betweenyour home office and your business office using security and encryption and theInternet as your transfer pipe.VPN is used to make the communication between two private networks over theInternet.A VPN carris private traffic over a public network using advanced encryption andtunnels to protect: .Confentiality of Information .integrity of data .Authentication of users A VPN is used to make the tunnel between two private netwoks over theinternet. . A tunnel is a virtual point-point connection. . The tunnel carries one protocol inside another protocol . Encryption transforms content information intociphertext . Decryption restores content information fromciphertextTypes of VPN 1.Site to Site VPN 2.Remote Access VPNVPN with different Host 1.PC ( Host ) to PC (Host ) 2.PC (Host) to Router 3.Router to Router 4.Router toFirewall 5.Firewall to Firewall1.VPN used the protocols to make the tunnel , such as PPTP Point to Point Protocol L2TP Layer 2 Tunneling Protocol IPSEC Internet Protocol Security2.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 onlyauthorized users is able to decrypt the communication. PPTP Definition Point-to-Point Tunneling Protocol, a new technology for creatingVirtual Private Networks (VPNs) , developed jointly by Microsoft Corporation, U.S.Robotics, and several remote access vendor companies, known collectively as thePPTP Forum. A VPN is a private network of computers that uses the public Internet toconnect some nodes. Because the Internet is essentially an open network, the Point-to-Point Tunneling Protocol (PPTP) is used to ensure that messages transmitted fromone VPN node to another are secure. With PPTP, users can dial in to their corporatenetwork via the Internet. L2TP DefinitionShort for Layer Two (2) Tunneling Protocol, an extension to the PPP protocol that enables ISPs to operateVirtual Private Networks (VPNs). L2TP merges the best features of two other tunneling protocols: PPTPfrom Microsoft and L2F from Cisco Systems. Like PPTP, L2TP requires that the ISPs routers support theprotocol. IP SECURITYShort for IP Security, a set of protocols developed by the IETF to support secure exchange of packets at theIP 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 theheader 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 througha 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 usingdigital certificates