Ipsec Vpn; Chapter 18 Ipsec Vpn; Overview; What You Can Do In This Chapter - ZyXEL Communications NBG-5715 User Manual

18.1 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 75 IPSec VPN: Overview
The VPN tunnel connects the NBG5715 (X) and the remote IPSec router (Y). These routers then
connect the local network (A) and remote network (B).

18.2 What You Can Do in this Chapter

• Use the General screen to display and manage the NBG5715's VPN rules (tunnels)
on page 126).
• Use the SA Monitor screen to display and manage active VPN connections
139).
NBG5715 User's Guide
C
H A P T E R
VPN Tunnel
X

IPSec VPN

Y
(Section 18.6 on page
1 8
(Section 18.4
124