3.1.4,+3.1.5+VPN


 * 3.1.4 Identify the technologies required to provide a VPN.**
 * 3.1.5 Evaluate the use of a VPN.**

__**VPN** (Virtual Private Network)__: A secure network that uses primarily public, telecommunication infrastructures, such as the Internet, to provide remote offices or traveling users an access to a central organizational network. ([|VPN in Wikipedia])

There are __Three__ types of VPN:
 * 1) **Secure:** All traffic on the VPN must be encrypted, authenticated and is the sent along virtual tunnels.
 * 2) **Trusted:** All traffic on the VPN relies on the security of a providers network to protect the traffic.
 * 3) **Hybrid:** A combination of both secure and trusted technologies.

Site to Site VPN
A site to site VPN allows offices in different locations to connect securely over a public network, such as the internet. Each site has a VPN gateway, like a router, firewall or concentrator. The VPN is in charge of encapsulating and encrypting all outbound traffic and sending it through a VPN tunnel over the internet to a peer VPN gateway at the target site. On receiving the packet the VPN gateway strips the headers, decrypts the content and relays the packet towards the target host inside the private network.



Remote Access VPN
In a Remote-access VPN, clients, such as telecommuters, mobile users, and extranet consumers, are able to access a company network securely over the Internet. Each host and client typically have VPN client software loaded or uses a web-based client. Whenever the host tries to send any information, the VPN client software encapsulates and encrypts the information before sending it over the internet to the VPN gateway at the edge of the target network. On receiving the packet the VPN gateway strips the headers, decrypts the content and relays the packet towards the target host inside the private network.



VPN Technologies

 * **Secure** || **Trusted** ||
 * IPsec (Ip security) || ATM circuits ||
 * SSL || Frame relay circuits ||
 * PPTP (point-to-point tunneling protocol) || MPLS ||
 * L2TP (Layer 2 tunneling protocol) || VPLS (VLAN) ||
 * L2TPv3 ||  ||
 * ViPNet VPN (IP VPN) ||  ||

Conclusion

 * ===Advantages=== || ===Disadvantages=== ||
 * Security || QoS (Quality of Serivce) management ||
 * Cost savings || Compatibility ||
 * Ease ||  ||
 * Speed ||  ||
 * Scalability ||  ||

[|HowStuffWorks explains VPNs]

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