This KB addressed the issue where an unexpected reboot is observed on QFX5120-32C switch.

The issue could be observed without a potential trigger.

• At random intervals the QFX5120-32C was seen rebooting. And the reason for the reboot was reflecting as “ 0x2000:hypervisor reboot” under "show chassis routing-engine" command.
• QFX functions following a reboot, and logs don't point to any known issue triggering the reboot.

Solution:

There is a possibility of this issue being caused by Transactional Synchronisation Extensions which is used in QFX5120-32C platform.

Such unexpected reboots were observed on QFX5120-32C and as per an internal PR, CPU CPLD and BIOS version upgrade is suggested to avoid such unexpected reboot scenarios.

Work with TAC Team to check the issue further.