Mobile IPv6
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Mobile IPv6 is a network layer IP standard used by electronic devices to exchange data across a packet-switched internetwork. Mobile IPv6 allows an IPv6 node to be mobile—to arbitrarily change its location on an IPv6 network—and still maintain existing connections.
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[edit] Overview
[edit] Limitations of "fixed" IPv6
When an IPv6 node changes its location, it might also change its link. When an IPv6 node changes its link, its IPv6 address might also change in order to maintain connectivity. There are mechanisms to allow for the change in addresses when moving to a different link, such as stateful and stateless address autoconfiguration for IPv6. However, when the address changes, the existing connections of the mobile node that are using the address assigned from the previously connected link cannot be maintained and are ungracefully terminated.
[edit] Enter Mobile IPv6
The key benefit of Mobile IPv6 is that even though the mobile node changes locations and addresses, the existing connections through which the mobile node is communicating are maintained. To accomplish this, connections to mobile nodes are made with a specific address that is always assigned to the mobile node, and through which the mobile node is always reachable. Mobile IPv6 provides Transport layer connection survivability when a node moves from one link to another by performing address maintenance for mobile nodes at the Internet layer.
[edit] Changes from IPv6 to Mobile IPv6
- A set of mobility options to include in mobility messages
- A new Home Address option for the Destination Options header
- A new Type 2 Routing header
- New Internet Control Message Protocol for IPv6 (ICMPv6) messages to discover the set of home agents and to obtain the prefix of the home link
- Changes to router discovery messages and options and additional Neighbor Discovery options
