IP version 6 (IPv6) is a new version of the Internet Protocol, designed as the successor to IP version 4 (IPv4) [RFC-791]. The changes from IPv4 to IPv6 fall primarily into the following categories:
Expanded addressing capabilities
Header format simplification
Improved support for extensions and options
Flow labeling capability
Authentication and privacy capabilities
You should have basic knowledge of IPv6 stateless auto-configuring to fully understand how 'mobile IPv6' (MIPv6) works. You can read up on IPv6 Stateless Address Autoconfiguration in [RFC2462].
For more information on IPv6 in general, visit the IETF's IPv6 Working Group.