3Com 4210 9-Port - Suppressing Flooding of Unknown Multicast Traffic in a VLAN

2-10
Operation Command Remarks
Enable IGMP Snooping
igmp-snooping enable
Required
By default, IGMP Snooping is
disabled.
Enable IGMP Snooping querier
igmp-snooping querier
Required
By default, IGMP Snooping
querier is disabled.
Configuring IGMP query interval
Follow these steps to configure IGMP query interval:
Operation Command Remarks
Enter system view
system-view
—
Enter VLAN view
vlan vlan-id
—
Configure the IGMP query
interval
igmp-snooping
query-interval seconds
Optional
60 seconds by default.
Configuring the source address to be carried in IGMP queries
Follow these steps to configure the source address to be carried in IGMP queries:
Operation Command Remarks
Enter system view
system-view
—
Enter VLAN view
vlan vlan-id
—
Configure the source IP
address of IGMP general
queries
igmp-snooping
general-query source-ip
{ current-interface |
ip-address }
Optional
0.0.0.0 by default
Configure the source IP
address of IGMP group-specific
queries
igmp-snooping
special-query source-ip
{ current-interface |
ip-address }
0.0.0.0 by default
Suppressing Flooding of Unknown Multicast Traffic in a VLAN
With IGMP Snooping enabled in a VLAN, multicast traffic for unknown multicast groups is flooded within
the VLAN by default. This wastes network bandwidth and affects multicast forwarding efficiency.
With the unknown multicast flooding suppression function enabled, when receiving a multicast packet
for an unknown multicast group, an IGMP Snooping switch creates a nonflooding entry and relays the
packet to router ports only, instead of flooding the packet within the VLAN. If the switch has no router
ports, it drops the multicast packet.
Table 2-11 Suppress flooding of unknown multicast traffic in the VLAN
Operation Command Remarks
Enter system view
system-view
—