To configure your node as a mobile node, add the following lines to /etc/rc.conf:
ipv6_mobile_enable="YES" ipv6_mobile_config_dir="/usr/local/v6/etc/mobileip6" ipv6_mobile_nodetype="mobile_node"
ipv6_mobile_home_prefixes=
ipv6_mobile_home_prefixes with your home prefix.
Replacing ipv6_mobile_home_prefixes with your home prefix.