ZyXEL 2WG Guida Utente

ZyWALL 2WG User’s Guide

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 provides one perspective of a VPN tunnel.

Figure 188   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).

• Use the VPN Rules (IKE) screens (see 

) to manage the 

ZyWALL’s list of VPN rules (tunnels) that use IKE SAs. 

• Use the VPN Rules (Manual) screens (see 

) to manage the 

ZyWALL’s list of VPN rules (tunnels) that use manual keys. You may want to configure a 
VPN rule that uses manual key management if you are having problems with IKE key 
management.

• Use the SA Monitor screen (see 

) to display and manage active 

VPN connections.