Be Ware of Services Interruption on OptiX OSN 3500

Summary:
On a port of an SSN1PEG16 or SSN1PEX1 board of a version earlier than V200R011C03SPC100, both LAG and CAR are enabled. After the board is upgraded to a version between V200R011C03SPC100 and V200R013C10SPC100 (itself excluded), the board is repeatedly reset due to a software bug. As a result, services are interrupted.

[Problem Description]
Trigger conditions:
The problem occurs when the following conditions are met: On a port of  Huawei Service board SSN1PEG16 or SSN1PEX1 of a version earlier than V200R011C03SPC100, both LAG and CAR are enabled. The board is upgraded to a version between V200R011C03SPC100 and V200R013C10SPC100 (itself excluded).
Symptom:
An SSN1PEG16 or SSN1PEX1 board is repeatedly reset and services on the board are interrupted.
Identification method:
Check whether the current NE version is V100R009C03 or a V200R011 version earlier than V200R011C03SPC100.
Check whether the target version of the upgrade is between V200R011C03SPC100 and V200R013C10SPC100 (itself excluded).
Check the board configuration. Check whether a port on the faulty board is configured with LAG and CAR.

[Root Cause]
This issue is caused by a software bug. When CAR is enabled for a slave port in a LAG on an SSN1PEG16 or SSN1PEX1 board of V200R011C03SPC100, the scenario that the board version was smoothly upgraded from another historical version is not considered. When the SSN1PEG16 or SSN1PEX1 board gets online, the database does not apply for the CARID resource for the slave port. Therefore, after the slave port gets online, it fails to obtain a CARID resource and the default CARID of 0 is used. As a result, verification of board parameters fails and the board is reset.

[Impact and Risk]
Services are interrupted.

[Measures and Solutions]
Recovery measures:
If the NE has two SCC boards, switch over the active and standby SCC boards.
If the NE has only one SCC board, warm reset the SCC board.

Workarounds:
During an upgrade, before activating an SSN1PEG16 or SSN1PEX1 board, switch over the active and standby SCC boards. For details, see the Guide to Prevent Interruption to Services on SSN1PEG16&SSN1PEX1 Boards of Huawei OptiX OSN 3500 After an Upgrade. Here for more huawei transmission equipment
Solution:
Upgrade the faulty NE to V200R013C10 or a later version.