ZyXEL Communications Internet Security Gateway ZyWALL 2 Series - Manual (Page 203)

ZyWALL 2 Series User’s Guide
Introduction to IPSec 13-3
13.2 IPSec Architecture
The overall IPSec architecture is shown as follows.
Figure 13-2 IPSec Architecture
13.2.1 IPSec Algorithms
The ESP (Encapsulating Security Payload) Protocol (RFC 2406) and AH (Authentication Header) protocol
(RFC 2402) describe the packet formats and the default standards for packet structure (including
implementation algorithms).
The Encryption Algorithm describes the use of encryption techniques such as DES (Data Encryption
Standard) and Triple DES algorithms.
The Authentication Algorithms, HMAC-MD5 (RFC 2403) and HMAC-SHA-1 (RFC 2404, provide an
authentication mechanism for the AH and ESP protocols. Please see 14.2 for more information.
13.2.2 Key Management
Key management allows you to determine whether to use IKE (ISAKMP) or manual key configuration in
order to set up a VPN.