3Com SuperStack 4 Configuration Manual page 165

Common Multicast
Configuration
Enabling Multicast
Configuring Multicast
Route Limit
Diagnosis 3: Multicast forwarding table set up on the bottom layer is wrong.
1 Enable IGMP Snooping group in user view and then input the command
igmp-snooping group
layer and that created by IGMP Snooping is consistent. You may also input the
display mac vlan
table under vlanid in the bottom layer and that created by IGMP Snooping is
consistent.
2 If they are not consistent, refer to Technical Support for assistance.
A common multicast configuration covers both the multicast group management
protocol and the multicast routing protocol. The configuration includes enabling
multicast, configuring the multicast forwarding boundary, and displaying the
multicast routing table and multicast forwarding table.
Common multicast configuration includes:
Enabling multicast
■
Configuring the multicast route limit
■
Clearing MFC forwarding entries or statistics information
■
Clearing route entries from the core multicast routing table
■
Enable multicast first before enabling IGMP and the multicast routing protocol.
Perform the following configuration in system view.
Table 183 Enabling multicast
Operation
Enable multicast
Disable multicast
By default, multicast is disabled.
Other multicast configurations can only become effective when multicast is
enabled.
If the existing route entries exceed the capacity value you configured using this
command, the system will not delete the existing entries. The following prompt is
shown;
Existing route entries exceed the configured capacity value
Perform the following configuration in System view:
Table 184 Configuring Multiast Route Limit
Operation
Configure number limit of multicast routing
entries
Restore the default number limit
to check if MAC multicast forwarding table in the bottom
command in any view to check if MAC multicast forwarding
Command
multicast routing-enable
undo multicast routing-enable
Command
multicast route-limit
undo multicast route-limit
Common Multicast Configuration
limit
177
display
.