Description

This article describes the Flexible PIC Concentrator (FPC) misconfiguration alarm, which is generated due to high power consumption by the Dense Port Concentrators (DPCs).

Symptoms

Even though the MX960 router can support any combination of the 11 DPCs and the redundant third SCB, the power supply cannot support all 12 DPCs if an Enhanced Queuing DPC is inserted into any slot of a fully loaded chassis. The Enhanced Queuing DPCs exhibit the following behavior:

  • When an Enhanced Queuing DPC is inserted in slot 6 of a powered-on MX960 router, the DPC will not power on.

  • When a DPC is inserted in slot 6 of an MX960 router that contains an Enhanced Queuing DPC in any slot, the DPC will not power on.

  • When an Enhanced Queuing DPC is inserted in any slot of an MX960 router that contains an already powered on DPC in slot 6, the Enhanced Queuing DPC will not power on.

Solution

These scenarios lead to an FPC misconfiguration alarm, which is generated due to high power consumption by the DPCs. To clear the alarm, perform one of the following actions:

  • To temporarily take the DPC offline, use the request chassis fpc slot slot-number offline command via the CLI.

    Note: The router does not preserve the state after a reboot.

  • To take the DPC offline and preserve the state after a reboot, use the set chassis fpc slot-number power off command via the configuration mode.

  • Remove the powered off DPC from the MX960 router. 

The following best practices are also recommended:

  • Use all other slots before using slot 6.

  • Remove any unused DPCs that are plugged in the MX960 chassis.

Note: This alarm can also be triggered when the MX device is not running a supported Junos OS version for a particular DPC.

Modification History

2022-08-11: Article checked for accuracy and found valid