Multicast host operations are fully supported in FreeBSD 2.0 and
later by default. If you want your box to run as a multicast router,
you will need to recompile your kernel with the MROUTING
option and run mrouted. FreeBSD 2.2 and later will start
mrouted at boot time if the flag mrouted_enable is set
to "YES" in /etc/rc.conf.
MBONE tools are available in their own ports category, mbone. If
you are looking for the conference tools vic and vat,
look there!
For more information, see the Mbone Information Web.