Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?


Troubleshooting a Modular Port Concentrator (MPC)



The following LEDs indicate a problem with an MPC:

  • The red FAIL LED above the MPC is lit.

  • The green OK LED above the MPC is not lit.


To troubleshoot an MPC:

  1. Monitor the green LED labeled OK above the MPC on the craft interface as soon as an MPC is seated in an operating router.


    The Control Board and Routing Engine (CB-RE) downloads the MPC software to it under two conditions: The MPC is present when the CB-RE boots Junos OS, and the MPC is installed and requested online through the CLI or push button on the front panel. The MPC then runs diagnostics, during which the OK LED blinks. When the MPC is online and functioning normally, the OK LED lights green steadily.

  2. Look at the display on the craft interface to check the status of the MPC and the MICs that are plugged into it.

  3. Verify that the MPC is properly seated in the top and bottom backplanes of the adapter card (ADC). Check that each knob has been turned clockwise and is tight.

  4. Check the OK/FAIL LED on the MPC, and OK and FAIL line card LEDs, LC0 through LC9, and LC10 through LC19 on the craft interface. When the MPC is online and functioning normally, the OK LED lights green steadily.

  5. Check the status of an MPC using the following CLI command: show chassis fpc command to check the status of installed MPCs. As shown in the sample output, the value Online in the column labeled State indicates that the MPC is functioning normally:

    Use the following option to display more detailed information: detail option. The following example does not specify a slot number, which is optional:

    For further description of the output from the commands, see the Junos OS System Basics Configuration Guide.