HP-UX IPSec version A.02.00 Administrator's Guide

HP-UX IPSec Overview
HP-UX IPSec Topologies
Chapter 144
NOTE In an Host-to-Gateway topology, the gateway cannot be an HP-UX
system unless the gateway is an HP-UX Mobile IPv6 Home Agent, and
the gateway functionality is used only to forward packets for Mobile
IPv6.
Host-to-Host Tunnel Topology
Two end hosts with HP-UX IPSec protection can configure a tunnel
policy that securely protects traffic between them. The tunnel adds extra
protection; an intruder cannot see the real IP headers of packets
traveling between the hosts.
The host-to-host tunnel topology is commonly used in an iSCSI
environment.
Figure 1-13 Host-to-Host Tunnel Topology