Introducing HP-UX Mobile IPv6

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2.3.4 Dynamic Home Agent Address Discovery
Dynamic Home Agent Address Discovery (DHAAD) allows Mobile Nodes that are away from their
home network, and have their home network prefix configured, to dynamically find the address of a
Home Agent on their home network. The following list is an overview of the DHAAD process:
• Each Home Agent listens to Router Advertisement messages sent by the other Home Agents and
records the addresses of these Home Agents.
• The Home Agents listen for Home Agent address requests from the Mobile Nodes (DHAAD requests)
on a special IPv6 subnet anycast address for the home network, the Mobile IPv6 Home-Agents anycast
address (anycast identifier 0x7E).
• The Mobile Node attaches to a foreign network and needs to send a Binding Update to a Home Agent
on its home network, but does not have an address for a Home Agent.
• The Mobile Node sends an ICMPv6 DHAAD request message to the Mobile IPv6 Home Agent’s subnet
anycast address for its home network.
• The Home Agents send back ICMPv6 DHAAD response messages with a list of global unicast
addresses for the Home Agents on the home network. The list may include preference values for the
Home Agents.
• The Mobile Node then sends a Binding Update with its Care-of Address to any Home Agent in the list. If
the Mobile Node does not receive a response, it may send a Binding Update to another Home Agent.
2.3.5 Prefix Discovery
Prefix Discovery allows a Mobile Node to get network prefix information about its home network. The
Home Agent monitors network prefix information from Router Advertisement messages on the home
network. A Mobile Node can request prefix information by sending a Mobile Prefix Solicitation
message to the Home Agent. The Mobile Node can use the prefix information to configure its Home
Address if needed.
2.3.6 Multi-Processor Scaling
HP designed and implemented HP-UX Mobile IPv6 for multi-processor scaling in environments using
high-end systems; supporting a large number of Mobile Nodes; and, requiring peak performance.
Scaling the number processors increases the number of Kernel-module instances processing mobility
message headers on the system.
2.3.7 Compatibility with HP-UX IPSec A.02.00
Security was a major design consideration for Mobile IPv6 because signaling and data packet
messages travel through the public Internet. Mobile IPv6 uses IPSec to protect the traffic between the
Mobile Node and its Home Agent. In addition to providing the HP-UX Mobile IPv6 piece of the mobility
puzzle, HP also provides HP-UX IPSec A.02.00 to secure the following messages sent between the
Mobile Node and Home Agent:
• Binding Update and Binding Acknowledgement messages
• ICMPv6 Mobile Prefix Solicitation and Mobile Prefix Advertisement messages
• Home Test-Init and Home Test messages during the return routability procedure
2.3.9 TAHI Conformance and Connectathon Interoperability Testing
HP is dedicated to providing standards-based computing products that interoperate in multi-vendor
environments. HP continued this tradition with HP-UX Mobile IPv6 by successfully passing TAHI
Project conformance tests and 2004 Connectathon interoperability tests.
Refer to the TAHI Project website at http://www.tahi.org/
and the Connectathon website at
http://www.connectathon.org/
for more information.
2.3.10 nettl and netfmt Tool Support
To simplify and expedite the troubleshooting process, HP enhanced the nettl tracing tool and the
netfmt formatting tool to support HP-UX Mobile IPv6. You can use the nettl and netfmt tools to trace
and format Mobile IPv6 Mobility Header and ICMPv6 messages.