to avoid error messages printed on /var/log/messages.
Recently added "stf" interface has IFF_MULTICAST bit set,
because IPv6 don't work on non IFF_MULTICAST set interfaces
in current implementation.
But "stf" interface is multi-dest IPv6 over IPv4 tunnel, so
can't treat multicast packet with no special configuration.
On the other hand, tools like "rtadvd", "pim6dd", "pim6sd"
send messages on IFF_MULTICAST set interfaces by default.
So there will be many bogus error message on /var/log/messages,
that multicast packets sent to "stf0" failed.
So,
-strip "stf0" from rtadvd sending interfaces in rc.network6
("rtadvd" is a daemon used only for local subnet, so it
will never need to send its packets over "stf0" interfaces.)
-Add default configuration files for "pim6dd" and "pim6sd",
and disable "stf0" in those files.
Approved by: jkh