Mobile IP

[1]

MOBILE IP

Presented By:

IQxplorer

[2]

Features of IPv6• 128 bit address.

• Address Auto configuration– An IPv6 node configurs it address automatically by

using the router advertisements and it’s interface id.

• Extension Headers– Routing header

• For route optimization

– Destination Options header• For mobile node originated datagrams

[3]

Mobile IPv6 Terminology Mobile Node

The node which moves between the networks.

Home Agent

The node in the Home network which knows the information(like current location...etc) about the mobile node’s, which belongs to that network.

Correspondent NodeAny node which contacts the Mobile node.

[4]

Mobile IPv6 Terminology (Continued)Home Address

Address of the Mobile Node in the Home Network

Care-of Address

Addess of the Mobile Node in the Foreign network

Home Link

The link on which a mobile node's home subnet prefix is defined. Standard IP routing mechanisms will deliver packets destined for a mobile node's home address to its home link.

[5]

Foreign Link Any link other than the mobile node's home link.

Binding The association of the home address of amobile node

with a care-of address for that mobile node.

[6]

Mobile IPv6 Operation

• Mobile IPv6 operation can be divided in to 3 parts

Discovering the care-of address Registering the care-of address Tunneling to the care-of address

[7]

Mobile IPv6 Operation (cont...)

• Discovering the care-of address

A Mobile Node(MN) performs address autoconfiguration to get its care-of address

• Resistsering the care-of address1. The MN registers its care-of address with its home agent

by sending a Binding Update request to it’s Home Agent (HA)

2. HA sedns a Binding Acknowledgement to the corresponding mobile node.

[8]

Mobile IPv6 basic operationCorrespondent Node

<Correspondent Address>

Mobile Node

<Care-Of Address>

Bidirectionaltunnelling

Routeoptimization

<correspondent address> <-> <home address>

IP tu

nnel

Mobile Node

<Home Address>

Routing option

Home Agent

<Home Address>

[9]

Mobile IPv6 address updates

Mobile Node

Home Agent

Binding Update Ack

• Mobile Node needs to update the Home Agent on it’s current location– Binding Update message

– The Home Agent keeps this binding for future use

Mobile Node

[10]

Triangle Routing

[11]

Route Optimization

• MN may bind BU in pkts to CN, allowing CN to directly send pkts to MN– CN receive a pkt with BU in it, then update its Binding

Cache

– Just like any IPv6 node, every time it attempt to sent pkts, it check its Binding Cache:

• If there is an entry with CoA of the destination, use the CoA

• Otherwise, use the origin address

[12]

Route Optimization

[13]

– While away from home, an MN selects one router and one subnet prefix advertised by that router to use as the subnet prefix in its primary care-of address

– To wait for the periodically sent Router Advertisements

Movement Detection

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Dynamic Home Agent Address Discovery

It is possible that when the mobile node needs to send a Binding Update to its home agent to register its new primary care-of address, the mobile node may not know the address of any router on its home link that can serve as a home agent for it.

ICMP Home Agent Address Discovery Request message

ICMP Home Agent Address Discovery Reply message

[15]

工作站

筆記型電腦

電腦

路由器 Internet

路由器

路由器

工作站

Home Agent 3

Correspondent Node

Mobile Node

Router

Router

Router

Home LinkLink A

Link B

Link C

(1)Binding Update to Home-Agents anycast address(2)Binding Acknowledgement including the Home Agents List;

rejects the registration request

工作站

Home Agent 1 Home Agent 2

Home Agents List Preference ValueHome Agent 3 9Home Agent 1 2Home Agent 2 -3

• Larger Preference value indicate higher availability of the home agent

[16]

Conclusions

• Mobile IPv6 is – An efficient protocol for handling mobility with

IPv6– To minimize the control traffic needed to effect

mobility

[17]

THANK YOU