Reserved addresses excluded from IP multicast filtering
Traffic to IP multicast groups in the IP address
range of 224.0.0.0 to 224.0.0.255 will always be flooded because addresses
in this range are "well known" or "reserved" addresses. Thus, if IP
multicast is enabled, and there is an IP multicast group within the
reserved address range, traffic to that group will be flooded instead
of filtered by the switch.
NOTE:
In IP mode, nonreserved multicast IP addresses are not displayed as "reserved" addresses.