Hello
I would like to ask community members of the issue I have faced.
My company has considerable amount of 3750-X stack in production environment presenting our solutions to the customers. Hence it is extremely important to avoid any downtime for production environment and moreover to make upgrade process as smooth and straightforward as possible.
Currently all switch stacks (3750X) runs on IOS 12.2(55)SE9.
Meanwhile, due to security vulnerabilities currently our security team strongly insist to upgrade to IOS firmware of 15.2 branch.
Actually the chosen firmware is IOS 15.2(2)E7.
We do have lab for testing different topologies and for sure upgrades.
Unfortunately test upgrades encounter some weird issues: from 6 switches I have tried to upgrade, 5 of them failed to upgrade to 15.2 firmware. Of course MD5 very verified, firmware have been uploaded several times more. Additionally, different firmware version were used (15.2(2)E7, 15.2(2)E8, 15.2(4)E4, 15.2(2)E)
Each time the switch tested, unpacked firmware, but failed on loading to RAM stage:
@@@@
File "flash:c3750e-universalk9-mz.152-2.E7/c3750e-universalk9-mz.152-2.E7.bin" uncompressed and installed, entry point: 0x3000
executing...
Loading "flash:/c3750e-universalk9-mz.122-55.SE9.bin"...@@@
In case on flash the older firmware is not present -- the switch goes to ROMMON.
I have raised support case with TAC, however TAC engineers insist on hardware issue. This could be acceptable, however I have encounter same issue on 5 of 6 3750-X switches in the lab.
That is really gives me too much suspicions to consider problems in hardware of some switch amount. It is unlikely to have coincidence for 5 switches in a row with hardware issue which are present only on IOS 15.2 - moreover no issue can be seen on IOS 12.2 for example.
I have collected "sh version" outputs from the switches.
Please share your opinions and experience about such issues. To be honest I am a bit lost and can't predict the future behavior of production switches upgrade (which is upcoming)
Thank you very much in advance.
Best regards, Vladimir
