If the VSIs of two PEs to which a CE is dual homed are Up, the PE with the higher priority functions as the master PE, whereas the PE with the lower priority functions as the backup PE. Therefore, you should not assign the same priority to the PEs, because this hinders the master/backup PE negotiation.
Do as follows on the PEs:
The system view is displayed.
The VSI view is displayed.
The multi-homed preference is configured for a VSI.
When the VSIs of the two PEs that a CE accesses are Up, the PE with the higher preference serves as the active PE, and the PE with the lower preference works as the standby PE. The active PE is responsible for forwarding the traffic of the CE; the standby PE is only responsible for checking whether the VSI of the active PE is Up. After a PE is selected as the standby PE, the status of the VSI of the standby PE is set to Down. After the VSI of the active PE becomes Down, the standby PE becomes the new active PE.
After the BGP session between the two PEs that a CE accesses becomes Down, the PW of the PE with the lower preference becomes Up, and the PW between the two PEs becomes Up.