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Utilizing Multiple Home Links on Mobile IPv6

Waseda University

Hongbo Shi shi@goto.info.waseda.ac.jpShigeki Goto goto@goto.info.waseda.ac.jp

3/23/2004

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Mobile IP• Mobile IP (Mobility Support in IP)

– Provides the mobility function on IP Layer

• How to realize the Mobile IP– Home Address:

• An IP address for a Mobile Node’s permanent use when the node is working as a mobility node.

– Care-of Address• An IP address for Mobile Node’s temporary use when the

node is away from its Home Link. • An IP address will be changed frequently while the node

is changing its attached links.

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Triangle Routing in Mobile IPv4

Correspondent Node (CN)Mobile Node (MN)

Home Agent (HA)

Home Link

Foreign Link

Foreign Agent (FA)

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Route Optimization

Correspondent Node (CN) Mobile Node (MN)

Home Agent (HA)

Home Link

Foreign Link

Default Router

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Multiple Home Agents Mechanism

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Multiple Home Agents Mechanism

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Multiple Home Agent Mechanism (Cont’d)

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New Mobility Option

Home Agent Address Field: Multiple Home Agents’ IP addresses

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ICMP Home Agent Unreachable Error Message

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Test Environment

• KAME + FreeBSD

• Function addition to KAME– Home Agents Selection: Select 2 home agents

to support a mobile node– Binding Registration to multiple home agents

Binding Updates to multiple home agents

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Testbed

Home Agent 1

Home Agent 2

2001:200:1:1:: 2001:200:1:3::

ed1: 2001:200:1:2::1 wi0: 2001:200:1:1::2

fxp0: 2001:200:1:2::2

Foreign Link

Home Link

Mobile Node

ed1: 2001:200:1:3:240:26ff:fe4c:51fd

Foreign Link

2001:200:1:2::(IPv6 アドレス )

an0: 2001:200:1:1::3

ed1: 2001:200:1:3::1

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Lifetime: 420 secondsExpiration time:372 seconds

Sequence number: 34285Home Agent 1 IP address

Mobile Node Home Address

Mobile Node Care-of Address

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Sequence number: 34285+1=34286

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Lifetime: 420 secondsExpiration time:393 seconds

Home Agent 2 IP address

Mobile Node Home Address

Mobile Node Care-of Address

Sequence number: 10803

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Sequence number: 10803+1=10804

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Home Agent 2 IP address

Home Agent 1 IP address

Sequence Number: 34285

Mobile Node Home Address& Mobile Node Care-of Address

Sequence Number: 10803

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Sequence Number: 34285+1=34286

Sequence Number: 10803+1=10804

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Multiple Home Links Mechanism

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Mechanism

• A non-multihoming mobile node can have multiple home links– multiple home agents on different links

• A mobile node can have more than 2 different home addresses

• A mobile node only has 1 care-of address, if it is not a multihoming node

• Multiple Home Links is an extension system of Multiple Home Agents

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How to work

• Allow a mobile node to have multiple home links -> a mobile node can have multiple home addresses at a time to a network interface

• A mobile node has to send binding update or binding registration messages to its home agents which are on the links that the mobile node is not attached. – Certainly even when a mobile node is just attached to one of

its home links, the mobile node still needs to send binding update or registration messages to the other home agents on its different home links.

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ICMP Error Message

ICMP Home Agent Unreachable Error

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Multiple Home Links Mechanism

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Correspondent Node (CN)

Home Link 1

Home Link 2

Home Agent 3

Foreign Link

Mobile Node (MN)

Default Router

Home Agent 2

Home Agent 1 (HA)

Tunnel 1Tunnel 2Tunnel 3

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Correspondent Node (CN) Mobile Node (MN)

Home Link 1

Home Link 2

Home Agent 3

Foreign Link

Mobile Node Default Router

Binding UpdateHome Registration

Home Agent 2

Home Agent 1 (HA)

Send Binding Update Message MN is on a Foreign Link

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Send Binding Update Message MN is on a Home Link

Correspondent Node (CN)

Mobile Node (MN)

Home Link 1Home Link 2

Home Agent 3

Binding UpdateHome Registration

Home Agent 2

Home Agent 1 (HA)

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Home Agent 1

Home Agent 2

2001:200:1:3::/64

ed1: 2001:200:1:3::1

an0: 2001:200:1:2::1

fxp0: 2001:200:1:3::2

Foreign LinkHome Link 1

Mobile Node

hif0 (Home Addresses):

2001:200:1:2:207:85ff:fe92:532c

2001:200:1:4:207:85ff:fe92:532c

an0 (Care-of Address):

2001:200:1:3:207:85ff:fe92:532c

2001:200:1:4::/64

an0: 2001:200:1:2::2

Home Agent 3

2001:200:1:2::/64Home Link 2

Foreign Link2001:200:1:6::/64

r11: 2001:200:1:4::1

r10: 2001:200:1:3::3

fxp0: 2001:200:1:6::1

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Remaining Issues and Future Plan

• How to share a mobile node’s binding information among home agents

• How to cross-refer the home addresses of a mobile node