HP-UX IPSec version A.02.01 Administrator's Guide

HP-UX IPSec and HP-UX Mobile IPv6
Introduction
Appendix F 283
IPv6 Type 2 Routing Header—therefore, the binding messages are
processed as if the appropriate source and destination address fields
contain the Mobile Node’s Home Address.
Only Binding Update and Binding Acknowledgement messages
exchanged between the Home Agent and Mobile Node can be secured
using IPsec; Binding Update and Binding acknowledgement messages
exchanged between the Mobile Node and Correspondent Nodes are
secured using a Mobile IPv6 mechanism.
Return Routability Messages Between the Home Agent and
Mobile Node
RFC 3776 specifies that you should use ESP to secure Home Test Init
and Home Test messages between the Home Agent and Mobile Node.
(See Appendix A, “RFC 3776 Mandatory Support” on page 4 for the RFC
3776 extract.)
Using IPsec to secure the Home Test Init and Home Test messages
between the Home Agent and the Mobile Node provides protection from
attacks initiated from within the Mobile Node’s foreign network.
Mobile IPv6 uses a procedure known as the Return Routability
procedure when establishing Route Optimization. The Return
Routability procedure provides proof to the Correspondent Node that the
Mobile Node is reachable through two routes: one to the Mobile Node’s
claimed Care-of Address and one through the Mobile Node’s Home
Address.
In the initial phases of the Return Routability procedure, the Mobile
Node sends a Home Test Init message to the Correspondent Node
through the Home Agent. The Correspondent Node sends back a Home
Test message through the Home Agent that includes keying material.
The Mobile Node combines the keying material in the Home Test
message with keying material it receives through its Care-of Address to
form an authentication key. The Mobile Node uses the authentication
key to sign a Binding Update it sends to the Correspondent Node with its
current Care-of Address.