3com 2226 PLUS Manuale Utente

This switch uses IGMP (Internet Group 
Management Protocol) to query for any 
attached hosts that want to receive a specific 
multicast service. It identifies the ports 
containing hosts requesting to join the service 
and sends data out to those ports only. It then 
propagates the service request up to any 
neighboring multicast switch/router to ensure 
that it will continue to receive the multicast 
service. This procedure is called multicast 
filtering.

The purpose of IP multicast filtering is to 
optimize a switched network’s performance, so 
multicast packets will only be forwarded to 
those ports containing multicast group hosts or 
multicast routers/switches, instead of flooding 
traffic to all ports in the subnet (VLAN).

Choose enable or disable from the IGMP 
Snooping Mode drop down menu.

Figure 34   IGMP Snooping Setup Screen

Choose enable or disable from the IGMP Query 
Mode drop down menu.

Figure 35   IGMP Query Setup Screen

Use the Broadcast Storm page to set the 
Switch’s broadcast storm control and threshold 
limits.