The igmp-snooping require-router-alert command configures a device to accept IGMP messages that contain the Router-Alert option in the IP header from a VLAN/VSI/BD.
Using the undo igmp-snooping require-router-alert command restores the default setting.
By default, the IGMP messages accepted by a device from a VLAN/VSI/BD do not need to carry the Router Alert option.
Usage Scenario
Router-Alert is a mechanism used to identify protocol packets. Packets carrying Router-Alert options are delivered to the routing protocol layer for processing.
By default, devices do not check whether packets carry Router-Alert options for the sake of compatibility, and send all IGMP messages to the upper layer for processing. To improve device performance, reduce costs, and ensure protocol security, the igmp-snooping require-router-alert command can be used to configure a device to discard IGMP messages that do not carry the Router-Alert option. After receiving IGMP messages, this device will check whether these messages carry the Router-Alert option. If the messages do not carry the Router-Alert option, this device will discard them.<HUAWEI> system-view [~HUAWEI] igmp-snooping enable [*HUAWEI] mpls [*HUAWEI-mpls] quit [*HUAWEI] mpls l2vpn [*HUAWEI-l2vpn] quit [*HUAWEI] vsi v1 [*HUAWEI-vsi-v1] igmp-snooping enable [*HUAWEI-vsi-v1] igmp-snooping require-router-alert