Summary:
When a warm reset is performed on a TN52XCH, TN52XCM, TNK2XCT, or TNK2SXM board that has not booted, the board becomes logically abnormal and cannot be restored to normal.
[Problem Description]
Trigger conditions:
For a TN52XCH, TN52XCM, TNK2XCT, or TNK2SXM board, when the physical board is installed but no logical board is configured or mapped, an upgrade in package loading or matching mode is performed and the board experiences a warm reset during the upgrade. The common application scenarios on the live network are as follows:
1. During a subrack expansion, a cross-connect board is added to the subrack and undergoes package loading or matching before the required logical board is configured.
2. During board replacement, a cross-connect board is added to the subrack and undergoes package loading or matching before the required logical board is configured or mapped.
Symptom:
When no BUS_ERR alarm is reported on the entire NE and no HARD_BAD alarm is reported for the cross-connect boards, the active/standby switching on the cross-connect boards fails.
Identification method:
During normal NE operation, run the SmartKit Inspector to check the following item:
Checking why the working status of the synchronous cross-connect board is set to abnormal and cannot be restored
[Root Cause]
This issue is a known issue of a synchronous cross-connect board. To be specific, if the software of a synchronous cross-connect board is (warm) reset before the board software starts to work, the working status of the board software will be set to abnormal after the board software gets started.
[Impact and Risk]
Active/standby switching cannot be performed on the cross-connect boards. As a result, services may be affected.
[Measures and Solutions]
Recovery measures:
When the system is properly operating, run the SmartKit Inspector. If any abnormality is found, rectify the abnormality according to the following handling suggestions:
Perform the following steps in the permitted maintenance windows:
1. If both the active and standby cross-connect boards in a subrack are malfunctioning, perform a cold reset on the standby cross-connect board. About 5 minutes later after the board software starts to work, active/standby switching will be automatically performed. After the active/standby switching is completed, perform a cold reset on the new standby cross-connect board.
2. If only one cross-connect board is malfunctioning in a subrack, perform the following operations:
If the standby cross-connect board is malfunctioning, perform a cold reset on it.
If the active cross-connect board is malfunctioning, check whether a fault occurs on the standby cross-connect board and rectify the fault if it is found. After the fault on the standby cross-connect board is rectified, active/standby switching will be automatically performed. After the active/standby switching is completed, perform a cold reset on the new standby optical transmission cross-connect board.
3. Check whether the cross-connect boards are normal.
Workarounds:
When no logical boards are loaded for cross-connect boards, do not upgrade the cross-connect boards in package loading or matching mode or perform a warm reset on the boards.
Preventive measures:
Upgrade the board software version to OptiX OSN 8800 V100R006C01SPC200 or later.
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