H3C Technologies H3C S5120 Series Switches - Manual (Page 321)

2-16
Configuring a Multicast Group Filter
On an IGMP snooping–enabled switch, the configuration of a multicast group allows the service
provider to define restrictions on multicast programs available to different users.
In an actual application, when a user requests a multicast program, the user’s host initiates an IGMP
report. Upon receiving this report message, the switch checks the report against the configured ACL
rule. If the port on which the report was received can join this multicast group, the switch adds an entry
for this port in the IGMP snooping forwarding table; otherwise the switch drops this report message. Any
multicast data that has failed the ACL check will not be sent to this port. In this way, the service provider
can control the VOD programs provided for multicast users.
Configuring a multicast group filter globally
Follow these steps to configure a multicast group filter globally:
To do... Use the command... Remarks
Enter system view system-view —
Enter IGMP snooping view igmp-snooping —
Configure a multicast group
filter group-policy acl-number
[ vlan vlan-list ]
Required
By default, no group filter is
globally configured, that is,
hosts in VLANs can join any
valid multicast group..
Configuring a multicast group filter on a port or a group of ports
Follow these steps to configure a multicast group filter on a port or a group of ports:
To do... Use the command... Remarks
Enter system view system-view —
interface interface-type
interface-number
Enter Ethernet interface/Layer
2 aggregate interface view or
port group view
port-group manual
port-group-name
Required
Use either approach
Configure a multicast group
filter igmp-snooping group-policy
acl-number [ vlan vlan-list ]
Required
By default, no group filter is
configured on the current port,
that is, hosts on this port can
join any valid multicast group.
Configuring the Function of Dropping Unknown Multicast Data
Unknown multicast data refers to multicast data for which no entries exist in the IGMP snooping
forwarding table. When the switch receives such multicast traffic:
z With the function of dropping unknown multicast data enabled, the switch drops all the unknown
multicast data received.
z With the function of dropping unknown multicast data disabled, the switch floods unknown
multicast data in the VLAN which the unknown multicast data belongs to.