ZyWALL 5/35/70 Series User’s Guide

Figure 143 Encryption and Decryption

18.1.3.2 Data Confidentiality

The IPSec sender can encrypt packets before transmitting them across a network.

18.1.3.3 Data Integrity

The IPSec receiver can validate packets sent by the IPSec sender to ensure that the data has not been altered during transmission.

18.1.3.4 Data Origin Authentication

The IPSec receiver can verify the source of IPSec packets. This service depends on the data integrity service.

18.1.4 VPN Applications

The ZyWALL supports the following VPN applications.

18.1.4.1 Linking Two or More Private Networks Together

Connect branch offices and business partners over the Internet with significant cost savings and improved performance when compared to leased lines between sites.

18.1.4.2 Accessing Network Resources When NAT Is Enabled

When NAT is enabled, remote users are not able to access hosts on the LAN unless the host is designated a public LAN server for that specific protocol. Since the VPN tunnel terminates inside the LAN, remote users will be able to access all computers that use private IP addresses on the LAN.

18.1.4.3 Unsupported IP Applications

A VPN tunnel may be created to add support for unsupported emerging IP applications. See Chapter 1 on page 50 for an example of a VPN application.

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Chapter 18 Introduction to IPSec