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IPSec VPN

20.1 IPSec VPN Overview

A virtual private network (VPN) provides secure communications between sites without the expense of leased site-to-site lines. A secure VPN is a combination of tunneling, encryption, authentication, access control and auditing. It is used to transport traffic over the Internet or any insecure network that uses TCP/IP for communication.

Internet Protocol Security (IPSec) is a standards-based VPN that offers flexible solutions for secure data communications across a public network like the Internet. IPSec is built around a number of standardized cryptographic techniques to provide confidentiality, data integrity and authentication at the IP layer. The following figure is an example of an IPSec VPN tunnel.

Figure 249 IPSec VPN Example

The VPN tunnel connects the ZyWALL (X) and the remote IPSec router (Y). These routers then connect the local network (A) and remote network (B).

20.1.1What You Can Do in the IPSec VPN Screens

•Use the VPN Connection screens (see Section 20.2 on page 353) to specify which VPN gateway a VPN connection policy uses and which devices (behind the IPSec routers) can use the VPN tunnel and the IPSec SA settings (phase 2 settings). You can also activate / deactivate and connect / disconnect each VPN connection (each IPSec SA).

•Use the VPN Gateway screens (see Section 20.2.1 on page 355) to manage the ZyWALL’s VPN gateways. A VPN gateway specifies the IPSec routers at either end of a VPN tunnel and the IKE SA settings (phase 1 settings). You can also activate and deactivate each VPN gateway.

 

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ZyWALL USG 100/200 Series User’s Guide