Ipsec Vpn; Chapter 20 Ipsec Vpn; Overview; What You Can Do In This Chapter - ZyXEL Communications SBG3500-N000 User Manual

20.1 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 provides one perspective of a VPN tunnel.
Figure 115 IPSec VPN: Overview
The VPN tunnel connects the SBG3500-N (X) and the remote IPSec router (Y). These routers then
connect the local network (A) and remote network (B).

20.2 What You Can Do in this Chapter

• Use the Setup screen to display and manage the SBG3500-N's IPSec VPN rules (tunnels)
(Section 20.4 on page
• Use the Monitor screen to display and manage active IPSec VPN connections
page 266).
• Use the Radius screen to manage the list of RADIUS servers the SBG3500-N can use in
authenticating users
SBG3500-N000 User's Guide
Network A
VPN Tunnel
X
257).
(Section 20.6 on page
C
HAPTER
Network B
Y
267).
2 0

IPSec VPN

(Section 20.5 on
256