What Is A Vpn - Cisco RVS4000 - Gigabit Security Router Administration Manual

Planning Your Virtual Private Network (VPN)

What is a VPN?

What is a VPN?
Cisco RVS4000 Security Router with VPN Administrator Guide
A VPN, or Virtual Private Network, is a connection between two endpoints—a VPN
router, for instance—in different networks that allows private data to be sent
securely over a shared or public network, such as the Internet. This establishes a
private network that can send data securely between these two locations or
networks.
This is done by creating a "tunnel". A VPN tunnel connects the two PCs or
networks and allows data to be transmitted over the Internet as if it were still
within those networks. Not a literal tunnel, it is a connection secured by encrypting
the data sent between the two networks.
VPN was created as a cost-effective alternative to using a private, dedicated,
leased line for a private network. Using industry standard encryption and
authentication techniques—IPSec, short for IP Security—VPN creates a secure
connection that, in effect, operates as if you were directly connected to your local
network. You can use VPN to create a secure network that links a central office
with branch offices, telecommuters, and/or professionals on the road (travelers
can connect to a VPN router by using any computer with the Cisco QuickVPN
Client software).
There are two basic ways to create a VPN connection:
• VPN router to VPN router
• Computer (using the Cisco QuickVPN Client software) to VPN router
The VPN router creates a "tunnel" or channel between two endpoints, so that data
transmissions between them are secure. A computer with the Cisco QuickVPN
Client software can be one of the two endpoints (refer to
Cisco QuickVPN for Windows 2000, XP, or
VPN client software, any computer with the built-in IPSec Security Manager
(Microsoft 2000 and XP) allows the VPN router to create a VPN tunnel by using
IPSec (refer to Appendix C, "Configuring IPSec with a Windows 2000 or XP
Computer"). Other versions of Microsoft operating systems require additional,
third-party VPN client software applications that support IPSec to be installed.
Appendix B, "Using
Vista"). If you choose not to run the
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