3Com S7902E, Руководство по настройке

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On an IGMP snooping proxy, IGMP membership reports are suppressed if the entries for the
corresponding groups exist in the forwarding table, no matter the suppression function is enabled or
not.
Configuring Maximum Multicast Groups that Can Be Joined on a Port
By configuring the maximum number of multicast groups that can be joined on a port, you can limit the
number of multicast programs on-demand available to users, thus to regulate traffic on the port.
Follow these steps to configure the maximum number of multicast groups allowed on a port or ports:
To do... Use the command... Remarks
Enter system view system-view —
interface interface-type
interface-number
Enter Ethernet port/ONU
port/Layer 2 aggregate
interface view or port group
view
port-group manual
port-group-name
Required
Use either approach
Configure the maximum
number of multicast groups
allowed on the port(s)
igmp-snooping group-limit
limit [ vlan vlan-list ]
Optional
1000 by default.
z
When the number of multicast groups a port has joined reaches the maximum number configured,
the system deletes all the forwarding entries persistent to that port from the IGMP snooping
forwarding table, and the hosts on this port need to join the multicast groups again.
z
If you have configured static or simulated joins on a port, however, when the number of multicast
groups on the port exceeds the configured threshold, the system deletes all the forwarding entries
persistent to that port from the IGMP snooping forwarding table and applies the static or simulated
joins again, until the number of multicast groups joined by the port comes back within the
configured threshold.
Configuring Multicast Group Replacement
For some special reasons, the number of multicast groups that can be joined on the current switch or
port may exceed the number configured for the switch or the port. In addition, in some specific
applications, a multicast group newly joined on the switch needs to replace an existing multicast group
automatically. A typical example is “channel switching”, namely, by joining a new multicast group, a user
automatically switches from the current multicast group to the new one.
To address such situations, you can enable the multicast group replacement function on the switch or
certain ports. When the number of multicast groups joined on the switch or a port has joined reaches the
limit: