Juniper JUNOSE 11.2.X IP SERVICES, Configuration Manual

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NOTE: You need to establish only one tunnel between the home agent and the CoA.
Demultiplexing of the traffic is done through IP address inspection.
Packets sent to the home address of the mobile node are redirected by the home agent
through the tunnel to the CoA at the foreign agent. The foreign agent routes the packets
to the mobile node's home address. If the mobile node's home address is a private address
or if the foreign agent implements ingress filtering, a reverse tunnel from the CoA to the
home agent is required.
You can use the Mobile IP home agent feature to configure the home agent within a
virtual router. The home agent handles the following tasks:
•
Agent discovery
• Registration
• Routing and forwarding
Mobile IP Agent Discovery
Mobile nodes use the agent discovery process to identify whether they are on their home
network or have roamed into a different network (referred to as a foreign network). Both
the foreign agent and the home agent periodically multicast their agent advertisements.
You can also request an agent advertisement from the mobile node through Internet
Control Message Protocol (ICMP) router solicitations.
Mobile IP Registration
The home agent receives the registration requests on UDP port 434. The registration
request contains the IP router ID as the home agent IP address. The home agent can
support static home address allocation and dynamic home address allocation.
Home Address Assignment
The mobile node's home address can either be preconfigured, or dynamically allocated
by the Mobile IP home agent. If a nonzero home address is preconfigured, the home agent
processes the registration request using the home address. If the home address is
dynamically allocated, the mobile node submits a nonzero home address and requests
the home agent to assign an IP address. The mobile node then uses the address provided
by the home agent for subsequent registration requests, until the mobile node is rebooted
or the registration expires.
Home address allocation is done by one of the existing AAA back-end address
mechanisms, such as:
•
By RADIUS
• From an address pool returned by RADIUS
• From a local pool
•
By the DHCP server
Copyright © 2010, Juniper Networks, Inc. 304
JunosE 11.2.x IP Services Configuration Guide