igmp-snooping limit-action

Usage Scenario

If the number of multicast groups on an interface or the switch reaches the limit, users connected to the interface or switch cannot join new multicast groups. To allow users to join new multicast groups in this case, enable multicast entry overwriting on interfaces in a VLAN.

After the configuration is complete, 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 switch has reached the limit, the switch checks all the programs that the user has ordered. If a program is watched only by this user, the switch replaces the entry of this program with the entry of the new program.

Prerequisites

To make the multicast entry overwriting configuration take effect, perform the following operations:

• Run the igmp-snooping enable (VLAN view) command to enable IGMP snooping in the VLAN.
• Run the igmp-snooping group-limit command to set the maximum number of multicast entries that an interface can learn.

Precautions

• The configuration takes effect only when IGMP snooping is enabled in the VLAN using the igmp-snooping enable (VLAN command) command.
• 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.