The mac-withdraw bd pw-tag enable command enables a PE to send MAC Withdraw messages that carry the PW tag to all its peers when the status of an EVC Layer 2 sub-interface changes or a BD goes Down.
The undo mac-withdraw bd pw-tag enable command restores the default configuration.
By default, a PE sends MAC Withdraw messages that do not carry the PW tag to all its peers when the status of an EVC Layer 2 sub-interface changes or a BD goes Down.
Usage Scenario
In a VPLS over EVC scenario, each BD functions as an access-side service instance and a VSI maps to multiple BDs. When the status of an EVC Layer 2 sub-interface changes, a PE sends MAC Withdraw messages that do not carry the PW tag to all its peers. When a peer receives this message, it clears MAC addresses in the VSI based on the message, causing the MAC addresses of other BDs to be deleted incorrectly. To solve this problem, run the mac-withdraw bd pw-tag enable command to enable the PE to send MAC Withdraw messages that carry the PW tag to its peers. Then, the peer will clear MAC addresses by BD, improving forwarding efficiency.
Precautions
This command must be used with the mac-withdraw enable command.
<HUAWEI> system-view [~HUAWEI] mpls [*HUAWEI-mpls] quit [*HUAWEI] mpls l2vpn [*HUAWEI-l2vpn] quit [*HUAWEI] vsi v1 bd-mode [*HUAWEI-vsi-v1] mac-withdraw enable [*HUAWEI-vsi-v1] mac-withdraw bd pw-tag enable