Symptom

FEX upgrade fails while doing Non Disruptive ISSU from 10.2(x) CCO train to 10.3(4a) CCO where the FEX parent switch is either of the following PIDs 1. N9K-C93180YC-FX3/FX3S 2. N9K-C93108TC-FX3P 3. N9K-C9364C-GX 4. N9K-C93600CD-GX

Conditions

1. Only seen with Non-disruptive upgrade 2. Source image for upgrade is 10.2(1),10.2(2),10.2(3),10.2(4),10.2(5) or 10.2(6) CCO images 3. Boot mode is "Native" in source image. 3. Target image for upgrade is 10.3(4a) CCO. 4. FEX parent is a either of the following TOR PIDS a. N9K-C93180YC-FX3/FX3S b. N9K-C93108TC-FX3P c. N9K-C9364C-GX d. N9K-C93600CD-GX

Workaround

1. Use disruptive upgrade for FEX connected FX3 parent switches when coming from 10.2(1),10.2(2),10.2(3),10.2(4),10.2(5) or 10.2(6) to 10.3(4a) 2. Use 10.2(7)M or later releases as intermediate hop 3. If already the FEX upgrade failed. then flap the FEX NIF port-channel on the device where ND ISSU failed. This will cause the FEX to redownload the image from parent.

Further Problem Description