Configuring the Limit on the Number of Multicast Entries Learned by an Interface
Context
By limiting the number of Layer 2 multicast entries learned on an interface, you can control the number of programs that users connected to the interface can order. This configuration limits the multicast data traffic volume on the interface.
If the number of existing multicast entries has reached or exceeded the configured value, users connected to the interface cannot join new groups. Layer 2 multicast entry overwriting can solve this problem. After Layer 2 multicast entry overwriting is configured, the switch records information about multicast users. When a user requests to join a new multicast group but the number of multicast groups on the interface or device has reached the limit, the switch checks all the programs that the user has ordered. If a program is being watched only by this user, the switch replaces the entry of this program with the entry of the new program.
Procedure
- Run system-view
The system view is displayed.
- Run interface interface-type interface-number
The interface view is displayed.
- Run igmp-snooping group-limit group-limit vlan { vlan-id1 [ to vlan-id2 ] } &<1-10>
The maximum number of multicast entries learned by the interface is configured.
During the configuration, if the number of multicast entries on the interface already exceeds the configured threshold, the number of multicast entries on the interface does not change and the interface cannot learn new multicast entries.
- (Optional) Run quit
Return to the system view.
- (Optional) Run vlan vlan-id
The VLAN view is displayed.
- (Optional) Run igmp-snooping limit-action
Layer 2 multicast entry overwriting is configured in the VLAN.
- When an interface is statically bound to a multicast group, the Layer 2 multicast entry overwriting function becomes invalid on the interface.
- The new multicast entry cannot replace the old one when the old multicast group has multiple multicast users or is a static multicast group.
- A new (S, G) entry can replace only an old (S, G), and a new (*, G) entry can replace only an old (*, G) entry.