This article explains the meaning of the "PLL_CMERROR_MPC_CORE_FREEZE (0x560001)" alarm that is seen on MX Series routers and indicates if any actions need to be taken.

The following log messages are seen on the Flexible PIC Concentrator (FPC):

Dec 17 07:00:09 XXXXXX : %PFE-5: fpc15 CMError: /fpc/15/pfe/0/cm/0/PLL_Core_Error/0/PLL_CMERROR_MPC_CORE_FREEZE (0x560001), scope: board, category: functional, severity: major, module: PLL Core Error, type: pll core Error 

Dec 17 07:00:09 XXXXXX : %PFE-5: fpc15 Performing action get-state for error /fpc/15/pfe/0/cm/0/PLL_Core_Error/0/PLL_CMERROR_MPC_CORE_FREEZE (0x560001) in module: PLL Core Error with scope: board category: functional level: major 

Dec 17 07:00:21 XXXXXX : %PFE-5: fpc15 Performing action cmalarm for error /fpc/15/pfe/0/cm/0/PLL_Core_Error/0/PLL_CMERROR_MPC_CORE_FREEZE (0x560001) in module: PLL Core Error with scope: board category: functional level: major 

Dec 17 07:00:21 XXXXXX : %PFE-3: fpc15 Cmerror Op Set: PLL Core Error: PTP EEC core is frozen (URI: /fpc/15/pfe/0/cm/0/PLL_Core_Error/0/PLL_CMERROR_MPC_CORE_FREEZE) 

Dec 17 07:00:21 XXXXXX alarmd[39021]: %DAEMON-4: Alarm set: FPC id=150998888, color=RED, class=CHASSIS, reason=FPC 15 Major Errors

XXXXXXX> show chassis errors active detail fpc-slot 15

Slot 15

--------------------------------------------------

Location   : FPC 15

Identifier  : /fpc/15/pfe/0/cm/0/PLL_Core_Error/0/PLL_CMERROR_MPC_CORE_FREEZE

Error     : PLL_CMERROR_MPC_CORE_FREEZE

Scope     : board

Category   : functional

Severity   : Major

Details    : pll core Error

Count     : 1

Support    : No help info provided

There are remote possibility of hitting PLL core hardware issue. 

PLL_CMERROR_MPC_CORE_FREEZE alarm would be seen if this issue is hit on an MPC

A major alarm "PLL Core Frozen" would be raised, if this issue is hit on SCBE3,

MPC need to be power cycled to cover from this alarm

Chassis need to be power cycled to recover SCBE3 in the problem state.->

In a rare occasion, an MPC, or an SCB3's hardware clock synchronization PLL module may not be able to lock on to the clocking signal during holdover. This caused by the "PLL Core" of the module hangs.

The change in this PR raises a "PLL Core Frozen" major alarm so the system can react to this by raising an alarm, and rebooting the affected MPC, or the SCBE3.

Perform these steps to determine the cause and resolve the problem (if any). Continue through each step until the problem is resolved.

Need to reboot the FPC to recover from error state.

Take the FPC offline and bring it online again or restart the FPC during a maintenance window, to clear a possible improper state on the chip

user@mx> request chassis fpc slot <slot number> offline

Wait for a few minutes.

user@mx> request chassis fpc slot <slot number> online

OR

user@mx> request chassis fpc slot <slot number> restart