An OSN 9800 NE reports alarms frequently. These alarms are reported at the same time but cleared at different times, as shown in the following figure.
1. Check the NE where alarmed are reported. The NE is formed by two OSN 9800 subracks in master-slave mode. Run the alm-init command to initialize these alarms. The fault persists.
2. Perform a switchover on the system control boards in the master OSN 9800 subrack. The fault persists after the switchover.
3. Analyze the alarms. The alarms from the boards in subrack 1 are intermittently reported, but those in the master subrack are normally reported. Check the black box logs of the device. It is found that the dmm communication of all boards in subrack 1 is unstable and the boards frequently go online and offline, as shown in the following figure.
4. It is suspected that the EFI board in the slave subrack is faulty. As a result, the dmm communication is unstable. After the 18EFI board in the slave subrack is replaced, the fault is rectified.
The EFI board is faulty. As a result, OSN 9800 alarms are intermittently reported.
Replace the EFI board.
If the EFI board is faulty, communication between the master and slave subracks may be affected. As a result, alarms are reported abnormally on the slave subrack.