igmp lastmember-queryinterval

Function

The igmp lastmember-queryinterval command configures interval at which an IGMP querier interface sends IGMP Group-Specific Query messages or IGMP Group-and-Source-Specific Query messages after receiving IGMP Leave messages from hosts.

The undo igmp lastmember-queryinterval command restores the default value.

By default, the interval at which an IGMP querier interface sends IGMP Group-Specific Query messages or IGMP Group-and-Source-Specific Query messages is 1s.

Format

igmp lastmember-queryinterval interval

undo igmp lastmember-queryinterval

Parameters

Parameter	Description	Value
interval	Specifies the interval at which an IGMP querier sends IGMP Group-Specific Query messages or IGMP Group-and-Source-Specific Query messages.	The value is an integer that ranges from 1 to 5, in seconds.

Views

GE interface view, XGE interface view, MultiGE interface view, 25GE interface view, 40GE interface view, 100GE interface view, Eth-Trunk interface view, GE sub-interface view, XGE sub-interface view, MultiGE sub-interface view, 25GE sub-interface view, 40GE sub-interface view, 100GE sub-interface view, Eth-Trunk sub-interface view, VLANIF interface view, loopback interface view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

When a querier receives a Leave message for a group, the querier periodically sends IGMP Group-Specific Query messages or IGMP Group-and-Source-Specific Query messages to check for other members in the group. The igmp lastmember-queryinterval command sets the interval at which the querier sends Last Member Query messages. The querier stops forwarding multicast data to the group if it receives no Report message from the group within the period specified by interval x robust-value. Here, robust-value is the robustness variable configured using the igmp robust-count or robust-count command.

If the querier receives at least one more Report message from the group within the specified period, the querier continues maintaining memberships of the group. Otherwise, the querier considers that the last member has left the group and no longer maintains memberships of the group.

Prerequisites

IP multicast routing has been enabled using the multicast routing-enable command.

Precautions

The igmp lastmember-queryinterval command is valid only when the IGMP querier runs IGMPv2 or IGMPv3.
The igmp lastmember-queryinterval command has the same function as the lastmember-queryinterval command used in the IGMP view. The configuration in the IGMP view takes effect for all interfaces, whereas the configuration in the interface view takes effect only for the specified interface. The configuration in the interface view takes precedence over the configuration in the IGMP view. The configuration in the IGMP view is used only when no configuration is performed in the interface view.

Example

# Set the interval for sending IGMP Group-Specific Query messages or IGMP Group-and-Source-Specific Query messages to 3 seconds on VLANIF100.

<HUAWEI> system-view
[HUAWEI] multicast routing-enable
[HUAWEI] interface vlanif 100
[HUAWEI-Vlanif100] igmp lastmember-queryinterval 3

# Set the interval for sending IGMP Group-Specific Query messages or IGMP Group-and-Source-Specific Query messages to 3 seconds on GE0/0/1.

<HUAWEI> system-view
[HUAWEI] multicast routing-enable
[HUAWEI] interface gigabitethernet 0/0/1
[HUAWEI-GigabitEthernet0/0/1] undo portswitch
[HUAWEI-GigabitEthernet0/0/1] igmp lastmember-queryinterval 3