Support for IPv6 mobility can be enabled in Linux by installing the MIPL2 implementation found at: https://www.mobile-ipv6.org/
This implementation is compliant with RFC 3775. It is composed of a kernel patch and a mobility daemon called mip6d. Version 2.0.1 applies on Linux kernel 2.6.15.
There also exists an implementation of network mobility for Linux, it is called NEPL and is based on MIPL. It can also be downloaded from: https://www.mobile-ipv6.org/.