Cisco VPN 3002 - Manual (Page 61)

C H A P T E R
6-1
VPN 3002 Hardware Client Reference
OL-1893-01
6
Tunneling
Tunneling is the heart of virtual private networking. Tunnels make it possible to use a public TCP/IP
network, such as the Internet, to create secure connections between remote users and a private corporate
network.
The secure connection is called a tunnel, and the VPN 3002 uses the IPSec tunneling protocol to:
• Negotiate tunnel parameters.
• Establish tunnels.
• Authenticate users and data.
• Manage security keys.
• Encrypt and decrypt data.
• Manage data transfer across the tunnel.
• Manage data transfer inbound and outbound as a tunnel endpoint.
The VPN 3002 functions as a bidirectional tunnel endpoint:
• It can receive plain packets from the private network, encapsulate them, create a tunnel, and send
them to the other end of the tunnel where they are unencapsulated and sent to their final destination
• It can receive encapsulated packets from the public network, unencapsulate them, and send them to
their final destination on the private network.
This section explains how to configure the IPSec tunneling protocol.