igmp on-demand

Function

The igmp on-demand command enables the IGMP on-demand function. This function enables a querier to maintain group memberships according to requirements of group members, without sending Query messages. After IGMP on-demand is enabled on an interface, dynamic IGMP entries on the interface will never age out.

The undo igmp on-demand command restores the default configuration.

By default, a querier does not maintain group memberships according to requirements of group members, and dynamic entries are aged out when the aging time expires.

Format

igmp on-demand

undo igmp on-demand

Parameters

None

Views

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

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

In a standard IGMP working process, a querier sends General Query messages periodically and collects group membership information based on received Report and Leave messages. Multicast group members respond to every Query message they receive. After IGMP on-demand is configured on the querier, the querier does not send Query messages, reducing IGMP packets exchanged between the querier and member hosts.

The IGMP on-demand function enables a querier to maintain group memberships based on requirements of members, without sending Query messages.

Prerequisites

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

Precautions

IGMP on-demand applies only to IGMPv2 and IGMPv3.
If dynamic IGMP entries have been generated on the querier, run the reset igmp group command to clear these dynamic IGMP entries before running the igmp on-demand command.
After the igmp on-demand command is executed on an interface (IGMP querier):
- The interface does not send IGMP Query messages
- IGMP group entries are generated after the interface receives IGMP Report messages and will never age out.
- When the interface receives an IGMP Leave message, it deletes the corresponding IGMP entry.

Example

# Enable the IGMP on-demand function on VLANIF100.

<HUAWEI> system-view
[HUAWEI] multicast routing-enable
[HUAWEI] interface vlanif 100
[HUAWEI-Vlanif100] igmp on-demand

# Enable the IGMP on-demand function 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 on-demand