A service provider runs a VPLS instance across three PE routers (PE1, PE2, PE3) in a full mesh of pseudowires. A dual-homed customer site connects to PE1 (active) and PE2 (standby) using MST for loop prevention. When the active uplink to PE1 fails and traffic shifts to PE2, remote PE3 continues black-holing customer traffic for the affected MAC addresses until they naturally age out. Which mechanism should be enabled to force PE3 to immediately relearn the MAC addresses on the correct pseudowire?