interface-status-change mac-withdraw enable

Function

The interface-status-change mac-withdraw enable command configures PEs to send LDP MAC Withdraw messages to all peers when the status of the AC interface bound to the VSI changes.

The undo interface-status-change mac-withdraw enable command disables PEs from sending LDP MAC Withdraw messages to all peers when the status of the AC interface bound to the VSI changes.

By default, a VSI does not send LDP MAC Withdraw messages.

Format

interface-status-change [ up | down ] mac-withdraw enable

undo interface-status-change [ up | down ] mac-withdraw enable

Parameters

Parameter	Description	Value
up	Configures a PE to send MAC Withdraw messages with the 0x404 TLV type to all peers when the bound AC interface goes Up. After a peer receives a MAC Withdraw message with the 0x404 TLV type, it clears MAC addresses in the VSI.	-
down	Configures a PE to send MAC Withdraw messages with the 0x406 TLV type to all peers when the bound AC interface goes Down. After a peer receives a MAC Withdraw message with the 0x406 TLV type, it clears MAC addresses learned by the VSI over a specific PW.	-

Parameter

Description

Value

Configures a PE to send MAC Withdraw messages with the 0x404 TLV type to all peers when the bound AC interface goes Up.

After a peer receives a MAC Withdraw message with the 0x404 TLV type, it clears MAC addresses in the VSI.

down

Configures a PE to send MAC Withdraw messages with the 0x406 TLV type to all peers when the bound AC interface goes Down.

After a peer receives a MAC Withdraw message with the 0x406 TLV type, it clears MAC addresses learned by the VSI over a specific PW.

Views

VSI-AUTO view, VSI-BD view, VSI-BVSI view, VSI-DEFAULT view, VSI-IVSI-P2P view, VSI-STATIC view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
l2vpn	write

Usage Guidelines

Usage Scenario

By default, when the status of an AC interface on a PE changes, the PE does not send MAC Withdraw messages to its peers. As a result, its peers are unaware of the fact that the CE connecting to that AC interface is unreachable. Subsequently, traffic bound to the CE gets lost before MAC addresses in the VSI age out. To solve this problem, run the

interface-status-change mac-withdraw enable command. Then, when the AC interface status changes, the PE sends a MAC Withdraw message to all its peers. After a peer receives the MAC Withdraw message, it clears MAC addresses in the VSI based on the MAC Withdraw message type.

When the status of an AC interface changes from Up to Down or an AC interface in the Up state leaves a VSI, the PE sends MAC Withdraw messages with the 0x406 TLV type to its peers. Upon receipt, a peer clears the MAC addresses learned over the specified PW from the VSI.
When the status of an AC interface changes from Down to Up or an AC interface in the Up state joins a VSI, the PE sends MAC Withdraw messages with the 0x404 TLV type to its peers. Upon receipt, a peer clears MAC addresses in the VSI.

Precautions

This command takes effect only after the mac-withdraw enable command is also used.

Example

# Enable the function to send LDP MAC Withdraw messages to all peers when the status of the AC interface bound to the VSI changes.

<HUAWEI> system-view
[~HUAWEI] mpls
[*HUAWEI-mpls] quit
[*HUAWEI] mpls l2vpn
[*HUAWEI-l2vpn] quit
[*HUAWEI] vsi v1 static
[*HUAWEI-vsi-v1] pwsignal ldp
[*HUAWEI-vsi-v1-ldp] interface-status-change mac-withdraw enable