Virtualprivatenetwork(VPN):

Virtual private networks are point-to-point connections across a private or public network such asthe Internet. A VPN client uses special TCP/IP-based protocols, called tunneling protocols, tomake avirtualcalltoavirtualport onaVPNserver.Inatypical VPNdeployment,aclientinitiates a virtual point-to-point connection to a remote access server over the Internet. Theremote access server answers the call, authenticates the caller, and transfers data between theVPNclientandthe organization'sprivate network.

TherearetwotypesofVPNconnections:

• RemoteaccessVPN

• Site-to-siteVPN

Remote access VPN connections enable users working at home or on the road to access aserver on a private network using the infrastructure provided by a public network, such as theInternet. From the user's perspective, the VPN is a point-to-point connection between thecomputer (the VPN client) and an organization's server. The exact infrastructure of the shared orpublic network is irrelevant because it appears logically as if the data is sent over a dedicatedprivate link.

Site-to-site VPN connections (also known as router-to-router VPN connections) enableorganizations to have routed connections between separate offices or with other organizationsover a public network while helping to maintain secure communications. A routed VPNconnection across the Internet logically operates as a dedicated WAN link. When networks areconnected over the Internet, as shown in the following figure, a router forwards packets toanother router across a VPN connection. To the routers, the VPN connection operates as a data-linklayerlink.

A site-to-site VPN connection connects two portions of a private network. The VPN serverprovides a routed connection to the network to which the VPN server is attached. The callingrouter (the VPN client) authenticates itself to the answering router (the VPN server), and, formutual authentication, the answering router authenticates itself to the calling router. In a site-tosite VPN connection, the packets sent from either router across the VPN connection typically donotoriginate attherouters

Question 1

1. With the use of a diagram explain what VPN is and how it can be used to provide securecommunicationsover theInternet.

1. ExplainthedifferencesbetweenVPNandVNC

Question 2

A salesman has been given a company laptop computer. They are currently attending a conference in another country but need to access their company's network and servers. Explain how; if they have access to the Internet, they could use a VPN to gain secure access their company's network. You may assume that the company network is also connected to the Internet via a Firewall.