IPSec can be employed between hosts (that is, end nodes),
between gateways, or between a host and a gateway in an IP network.
HP-UX IPSec can only be installed on end nodes. Installing HP-UX
IPSec on a gateway node is not supported.
End-to-End
Topology |
 |
Two end hosts can run HP-UX IPSec locally to protect communication between
them, with or without intermediate gateways.
End-to-End
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.
End-to-end tunnel topology is commonly used in an iSCSI environment.
Gateway-to-Gateway
Topology |
 |
Two hosts each reside upon insecure networks (such as insecure intranets).
These hosts need to communicate securely over an insecure public
network (such as the Internet). HP-UX IPSec can be used over a tunnel
between two (non-HP) IPSec gateways to provide additional end-to-end
security.