An FPC reboot accompanied by a DCPFE core dump occurs when multiple PFE‑level commands are executed simultaneously. Engineering analysis confirms this is a known limitation in the Broadcom SDK used on this platform. The SDK does not support multithreaded access for certain diagnostic shell (bcmshell) commands.

In this case, the command:

request pfe execute command "set dcbcm bcmshell \"l3 egress show\"" target fpc0

was executed repeatedly while an op script (op prefix_check) was running at the same time. The concurrent execution resulted in a synchronization issue across threads, ultimately causing the DCPFE core generation and forcing the FPC to reboot.

• FPC reboot triggered unexpectedly
• DCPFE core file generated
• Logs show repeated execution of l3 egress show at the time of the crash
• Backtrace (BT) confirms failure occurring in the Broadcom shell command handler:

sh_process_command(...) "l3 egress show"

• Concurrent command execution can be seen from interactive command logs , for example

Mar 2 13:44:25 mgd: request pfe execute command "l3 egress show"

Mar 2 13:44:20 mgd: op prefix_check

Avoid running PFE-level diagnostic commands concurrently, especially:

request pfe execute command …

Broadcom bcmshell commands such as l3 egress show

Do not run op prefix_check in parallel with PFE or bcmshell-based commands.

No permanent software fix is available at this time, as this behavior is tied to an SDK design limitation.