H3C Technologies H3C S3600 Series Switches - Manual (Page 403)

3-10
To do... Use the command... Remarks
Enter system view system-view —
Enter interface view interface interface-type interface-number —
In VLAN
interface view
igmp group-policy
acl-number [ 1 | 2 | port
interface-list ]
Configuring a multicast
group filter
In LoopBack
interface view igmp group-policy
acl-number [ 1 | 2 ]
Optional
No multicast group filter
is configured by default
Configuring a multicast group filter in Ethernet port view
Follow these steps to configure a multicast group filter in Ethernet port view:
To do... Use the command... Remarks
Enter system view system-view —
Enter Ethernet port view
interface interface-type
interface-number
—
Configuring a multicast group
filter igmp group-policy
acl-number vlan vlan-id
Optional
No multicast group filter is
configured by default. The port
must belong to the specified
VLAN.
Configuring Simulated Joining
Generally, hosts running IGMP respond to the IGMP query messages of the IGMP querier. If hosts fail to
respond for some reason, the multicast router may consider that there is no member of the multicast
group on the local subnet and remove the corresponding path.
To avoid this situation from happening, you can enable simulated joining on a port of the switch, namely
configure the port as a simulated member host for a multicast group. When the port receives IGMP
query messages, the simulated member host will respond. As a result, the subnet attached to the Layer
3 interface can continue to receive multicast traffic.
Through this configuration, the following functions can be implemented:
z When an Ethernet port is configured as a simulated member host, the switch sends an IGMP report
through this port. Meanwhile, the simulated host sends the same IGMP report to itself and
establishes a corresponding IGMP entry based on this report.
z When receiving an IGMP general query, the simulated host responds with an IGMP report.
Meanwhile, the simulated host sends the same IGMP report to itself to ensure that the IGMP entry
does not age out.
z When the simulated joining function is disabled on an Ethernet port, the simulated host sends an
IGMP leave message.
Therefore, to ensure that IGMP entries will not age out, the port must receive IGMP general queries
periodically.