mld robust-count

Function

The mld robust-count command sets a robustness variable for a Multicast Listener Discovery (MLD) querier.

The undo mld robust-count command restores the default value.

By default, the robustness variable of an MLD querier is 2.

Format

mld robust-count robust-value

undo mld robust-count

Parameters

Parameter	Description	Value
robust-value	Specifies the robustness variable of an MLD querier.	The value is an integer ranging from 2 to 5.

Parameter

Description

Value

robust-value

Specifies the robustness variable of an MLD querier.

The value is an integer ranging from 2 to 5.

Views

100ge sub-interface view, 100GE interface view, 10GE sub-interface view, 10GE interface view, 200GE sub-interface view, 25GE sub-interface view, 25GE interface view, 400GE sub-interface view, 400GE interface view, 40GE sub-interface view, 40GE interface view, 50GE sub-interface view, 50GE interface view, Eth-Trunk sub-interface view, Eth-Trunk interface view, FlexE interface view, GE optical interface view, GE sub-interface view, GE interface view, GE electrical interface view, Global VE sub-interface view, Loopback interface view, PW-VE sub-interface view, VE sub-interface view, VLANIF interface view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
igmp	write

Usage Guidelines

Usage Scenario

A robustness variable is used to define the following values:

Number of times for sending general query messages when the MLD querier starts
Number of times for sending group-specific query messages when the MLD querier receives a Report message
If a host running MLD needs to leave a group, the host sends an MLD Done message. If the MLD querier receives this message, it sends MLD last-listener query messages for the number of "robustness variable" times and at an interval which is set by using the mld lastlistener-queryinterval command. If the sending interval is not set, the default value is one second.
If another host receives the MLD last-listener query message from the MLD querier and wants to join the group, this host sends an MLD Report message within the maximum response time. If the MLD querier receives the MLD Report message from the host within the period (interval x robustness variable), the MLD querier continues to maintain the memberships for the group. If the MLD querier does not receive any Report message, the MLD querier considers that this group times out and stops maintaining the membership for the group.
If the robustness variable is set in both the interface view and the MLD view, the system prefers the value set in the interface view.

Example

# Set the robustness variable to 3 on GE 0/1/0.

<HUAWEI> system-view
[~HUAWEI] multicast ipv6 routing-enable
[*HUAWEI] interface GigabitEthernet 0/1/0
[*HUAWEI-GigabitEthernet0/1/0] ipv6 enable
[*HUAWEI-GigabitEthernet0/1/0] mld robust-count 3