Description

The FPC Type 3 on the MX-series chassis may go offline when it is abruptly removed before the PIC is put into an offline state. 

Symptoms

There is a probability of the MX FPC Type 3 going offline when the PIC connected to the FPC is abruptly removed from the chassis without  it being taken offline first.  The FPC will not come up until it is restarted or reseated.

Solution

This behavior is expected since it is never recommended to remove the PIC from the chassis without performing an offline. Even though similar behavior is not observed on any other chassis, this action could lead to such abnormalities.

Below is the documentation link which states that the PIC needs to be changed to an offline state before its removal from the chassis (point 3).

http://www.juniper.net/techpubs/en_US/release-independent/junos/topics/task/installation/pic-mx960-replacing.html

In case of MX-960, the abrupt removal of the PIC causes the FPC to go offline due to electrical issues as seen from the log messages below

Aug 5 11:30:35 atlas_i2cs_power_ok: FPC-2 Power Up State 0x00000020
Aug 5 11:30:35 atlas_i2cs_power_ok: FPC-2 Power Disable Cause 0x00000040
Aug 5 11:30:35 atlas_i2cs_power_ok: FPC-2 Power VFail 1 Cause 0x00000000
Aug 5 11:30:35 atlas_i2cs_power_ok: FPC-2 Power VFail 2 Cause 0x00000001
Aug 5 11:30:37 atlas_i2cs_power_ok: FPC-2 Power Up State 0x00000020
Aug 5 11:30:37 atlas_i2cs_power_ok: FPC-2 Power Disable Cause 0x00000040
Aug 5 11:30:37 atlas_i2cs_power_ok: FPC-2 Power VFail 1 Cause 0x00000000
Aug 5 11:30:37 atlas_i2cs_power_ok: FPC-2 Power VFail 2 Cause 0x00000001

Once the FPC has gone into an offline state the only way to recover it is to do an offline/online or physical reseat of the FPC.

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