TABLE OF CONTENTS An IPv6 address has a lifetime value. The lifetime is derived from the lifetime of the prefix. If the home address of a mobile node is going to expire, the mobile node sends a Mobile Prefix Solicitation message to get the latest information about home prefixes. The source address of the message is set to the care-of address of the mobile node. The destination of the message is the address of the home agent with which the mobile node is currently registered. The message must include a Home Address option which contains the home address of the mobile node (i.e., a Mobile Prefix Solicitation message can be sent only after successful home registration). Since the home registration procedure requires the information of a home network, this prefix discovery mechanism cannot be used to find the home prefixes when a mobile node is booting up on a foreign network, but can only be used to know new home prefixes or deprecated home prefixes.
When a home agent receives a Mobile Prefix Solicitation message from a mobile node, the node must reply to the mobile node with a Mobile Prefix Advertisement message. The source address of the message must be the destination address of the corresponding solicitation message. The destination address of the message must be the source address of the corresponding solicitation message, that is, the care-of address of a mobile node. A Type 2 Routing Header that contains the home address of a mobile node must...
