mld-snooping router-aging-time

Function

The mld-snooping router-aging-time command sets the aging time of dynamic router ports in a VLAN.

The undo mld-snooping router-aging-time command restores the default aging time of dynamic router ports in a VLAN.

By default, the aging time of dynamic router ports in a VLAN is 180 seconds or equal to the holdtime value contained in PIM Hello messages.

Format

mld-snooping router-aging-time router-aging-time

undo mld-snooping router-aging-time

Parameters

Parameter	Description	Value
router-aging-time	Indicates the aging time of a router port.	The value is an integer that ranges from 1 to 1000, in seconds.

Views

VLAN view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

When a short-term congestion occurs on a network, it takes a longer time to transmit Query messages from the MLD querier to a Layer 2 device. If a router port on the Layer 2 device ages out within this period, the Layer 2 device does not send Report or Done messages to the router port. As a result, multicast data forwarding may be interrupted. To solve this problem, set a longer aging time for router ports if the network is unstable.

When a dynamic router port receives an MLD Query message or PIM Hello message, the Layer 2 device sets the aging time of the router port as follows:

If the router port receives an MLD Query message, the Layer 2 device sets the aging time of the router port to the configured value.
If the router port receives a PIM Hello packet, the Layer 2 device sets the aging time of the router port to the Holdtime value contained in the PIM Hello packet.

Prerequisites

MLD snooping has been enabled globally using the mld-snooping enable command.

Precautions

The configuration takes effect only after you run the mld-snooping_enable command to enable MLD snooping in the VLAN.

If the aging time of a router port is too short, the router port ages frequently, degrading system performance.

Example

# Set the aging time of router ports in VLAN 3 to 300 seconds.

<HUAWEI> system-view
[HUAWEI] mld-snooping enable
[HUAWEI] vlan 3
[HUAWEI-vlan3] mld-snooping enable
[HUAWEI-vlan3] mld-snooping router-aging-time 300