Amer Networks E5Web GUI - Manual (Page 565)

Chapter 9: VPN
This chapter describes the Virtual Private Network (VPN) functionality in cOS Core.
• Overview, page 565
• VPN Quick Start, page 569
• IPsec Components, page 581
• IPsec Tunnels, page 597
• PPTP/L2TP, page 619
• SSL VPN, page 636
• CA Server Access, page 646
• VPN Troubleshooting, page 649
9.1. Overview
9.1.1. VPN Usage
The Internet is increasingly used as a means to connect together computers since it offers
efficient and inexpensive communication. The requirement therefore exists for data to traverse
the Internet to its intended recipient without another party being able to read or alter it.
It is equally important that the recipient can verify that no one is falsifying data, in other words,
pretending to be someone else. Virtual Private Networks (VPNs) meet this need, providing a
highly cost effective means of establishing secure links between two co-operating computers so
that data can be exchanged in a secure manner.
VPN allows the setting up of a tunnel between two devices known as tunnel endpoints. All data
flowing through the tunnel is then secure. The mechanism that provides tunnel security is
encryption.
There are two common scenarios where VPN is used:
1. LAN to LAN connection - Where two internal networks need to be connected together
over the Internet. In this case, each network is protected by an individual Clavister Security
Gateway and the VPN tunnel is set up between them.
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