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| Affected Product Name | Description | Comments |
|---|---|---|
| C2960X-STACK= | Catalyst 2960-X FlexStack Plus Stacking Module optional | Part Alternate |
| Defect ID | Headline |
| CSCuu00752 | Incorrect license programmed on flexstack-plus module |
An incorrect license was programmed into a limited number of Cisco 2960X FlexStack-Plus modules (C2960X-STACK=). With the incorrect license, the FlexStack module does not pass the SmartChip authentication during boot up, so the module is not recognized or supported by the switch chassis.
Cisco has found that less than 0.03% of the C2960X-STACK= module installation base was programmed with the incorrect license during the manufacturing process.
When a Cisco Catalyst 2960X Series switch is booted up with an affected C2960X-STACK= module, there are two error messages that might appear.
Here is the first error message that can appear:
POST: ACT2 Authentication: Begin
POST: ACT2 Authentication: End, Status Passed FlexStack Module SmartChip
Authentication Failed
Here is the second error message that can appear:
%ILET-1-DEVICE_AUTHENTICATION_FAIL: The FlexStack Module inserted in this switch may not have been manufactured by Cisco or with Cisco's authorization. If your use of this product is the cause of a support issue, Cisco may deny operation of the product, support under your warranty or under a Cisco technical support program such as Smartnet. Please contact Cisco's Technical Assistance Center for more information.
Solution
To determine if a C2960X-STACK= module is affected, see the Serial Number Validation section of this field notice.
Note that this is a Fix on Failure program. If a C2960X-STACK= module is identified as affected and exhibits the abnormal behavior described in the Problem Symptom section of this field notice, contact the Cisco Technical Assistance Center (TAC) for a replacement.
Modules that are identified as affected but are functioning normally do not currently require replacement.
To obtain the serial number of a C2960X-STACK= module, perform a physical inspection of the Serial Number label on the module:

| Version | Description | Section | Date |
| 10.2 | Updated the instructions for serial number validation. | Workaround/Solution | 2026-SEP-24 |
| 10.1 | Fixed the broken image link and updated the concept tags. | — | 2018-JUN-29 |
| 10.0 | Migrated to new field notice system. | — | 2017-OCT-12 |
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