ZyXEL Communications prestige 2602h series User Manual

Prestige 2602H/HW Series User’s Guide

Chapter 17 VPN Screens

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This chapter introduces the VPN screens. See the chapter on logs for information on viewing 
logs and the appendix on logs for IPSec log descriptions.

Use the screens documented in this chapter to configure rules for VPN connections and 
manage VPN connections.

The ESP and AH protocols are necessary to create a Security Association (SA), the 
foundation of an IPSec VPN. An SA is built from the authentication provided by the AH and 
ESP protocols. The primary function of key management is to establish and maintain the SA 
between systems. Once the SA is established, the transport of data may commence.

AH protocol (RFC 2402) was designed for integrity, authentication, sequence integrity (replay 
resistance), and non-repudiation but not for confidentiality, for which the ESP was designed. 

In applications where confidentiality is not required or not sanctioned by government 
encryption restrictions, an AH can be employed to ensure integrity. This type of 
implementation does not protect the information from dissemination but will allow for 
verification of the integrity of the information and authentication of the originator.