The igmp prompt-leave command enables the prompt leave function on an interface. After receiving a Leave message for a certain group, an interface immediately deletes the corresponding group records, without sending a last member query message.
The undo igmp prompt-leave command restores the default configuration.
| Parameter | Description | Value |
|---|---|---|
| acl-number | Specifies the number of a basic or advanced ACL. This list specifies the range of a multicast group. | The number of a basic ACL is an integer ranging from 2000 to 2999, while the number of an advanced ACL is an integer ranging from 3000 to 3999. |
By default, the interface sends a last member query message after receiving a Leave message from a host.
Usage Scenario
In most cases, after receiving a Leave message of a multicast group or source-specific multicast group, an interface sends a last member Query message to check whether this multicast group or source-specific multicast group has other members. To minimize the response delay and save network bandwidth, configure prompt leave on the interface. If prompt leave is configured on an interface, after receiving a Leave message of a multicast group or source-specific multicast group, the interface immediately deletes the corresponding multicast group or source-specific multicast group records, without sending a last member Query message.
Prerequisites
The multicast routing-enable command has been run in the public network instance view or the VPN instance view.
Configuration Impact
If this command is run more than once, the latest configuration overwrites the previous ones.
Precautions
If group-policy is not specified, prompt leave takes effect on all multicast groups or source-specific multicast groups.
Before setting group-policy, an ACL need to be configured. The interface then filters the received Leave messages according to this ACL.
If the group or source-specific group that a host wants to leave is within the multicast group range specified by the ACL, the FW directly deletes records about this group or source-specific group without sending a last member Query message.
If the group or source-specific group that a host wants to leave is beyond the multicast group range specified by the ACL, the FW sends a last member Query message.
The igmp prompt-leave and acl commands should be used together. Specify the source parameter in the rule command in the ACL view to set the address range of multicast groups or source-specific multicast groups that the host is to leave.
<sysname> system-view [sysname] multicast routing-enable [sysname] acl number 2005 [sysname-acl-basic-2005] rule permit source 225.1.0.0 0.0.255.255 [sysname-acl-basic-2005] quit [sysname] interface GigabitEthernet 0/0/1 [sysname-GigabitEthernet0/0/1] igmp prompt-leave group-policy 2005