Configuration files you have to edit:

/etc/rc.conf                          - system wide configuration file
/etc/rtadvd.conf                  - configuration file for the router advertisement daemon.

For FreeBSD and NetBSD users, there is a special rc script that enables MIPv6 configuration to be specified in /etc/rc.conf.

If you are using FreeBSD, you must copy rc and rc.mobileip6 in /kame/freebsd4/etc directory to the /etc directory.

If you are using NetBSD, you must copy the /kame/netbsd/etc/rc.d/mobileip6 file to the /etc/rc.d directory.

After this you can configure your node using rc.conf.