PFEX core dump generated on EX4300 VC & device went unreachable.

On Junos EX4300 platforms, a PFE process crash could be observed due to a rare timing issue that led to traffic loss during the time of the crash.

Pfeman keepalive counter is updated every one second against wall clock timer through one of the ukern thread. When ukern thread is not scheduled for long time as in this case, when ukern periodic background thread is scheduled later, All the callback during that missing period are sent one after the other in burst. When we have long starving of ukern thread,in burst this gets incremented and due to connectivity issue when pfeman goes to log and shutdown state, it crashes pfe with panic.

Resolved-In junos:21.4R3-S9 

2024-09-25 : Article Created

2026-10-01 : Updated and externalized