3Com 7700 Configuration Manual page 179

Limit ing Access to IP Multicast Groups
A multicast router learns whether there are members of a multicast group on the
network by the received IGMP membership message. A filter can be set on an
interface to limit the range of allowed multicast groups.
Perform the following configuration in VLAN-interface view.
Table 14 Limit the Access to IP Multicast Groups
Operation
Limit the range of allowed
multicast groups on current
interface
Remove the filter set on the
interface
By default, no filter is configured. All multicast groups are allowed on the
interface.
Configuring the IGMP Query Message Interval
Multicast routers send IGMP query messages to find present multicast groups on
other networks. Multicast routers send query messages periodically to refresh their
information of members present.
Perform the following configuration in VLAN interface view.
Table 15 Configure the IGMP Query Message Interval
Operation
Configure the IGMP query message
interval
Restore the IGMP query message
interval to the default value
When there are multiple multicast routers on a network segment, the querier is
responsible for sending IGMP query messages to all hosts on the LAN.
The default interval is 60 seconds.
Select the IGMP Version
Perform the following configuration in VLAN interface view.
Table 16 Select the IGMP Version
Operation
Select the IGMP version that the
router uses
Restore the default setting
By default, the router uses IGMP Version 2, which allows such features as the
IGMP query timeout time and the maximum query response time.
CAUTION: All routers on the subnet should support the same IGMP version.
Command
igmp group-policy acl-number [ 1 | 2 ]
undo igmp group-policy
Command
igmp timer query seconds
undo igmp timer query
Command
igmp version { 2 | 1 }
undo igmp version
IGMP Configuration 171