ZyXEL ZyWALL 5 User Guide - Page 357

CHAPTER 19 IPSec VPN 19.1 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 205 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). 19.1.1 What You Can Do in the IPSec VPN Screens • Use the VPN Rules (IKE) screens (see Section 19.2 on page 360) to manage the ZyWALL's list of VPN rules (tunnels) that use IKE SAs. • Use the VPN Rules (Manual) screens (see Section 19.7 on page 375) 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 Section 19.9 on page 379) to display and manage active VPN connections. ZyWALL 5/35/70 Series User's Guide 357