Syslog message: %PFE-3: fpc0 PE Chip:PE-1[1]: EPW: eprq_map_disabled error in QFX10K devices

Summary:

This article explains why the "%PFE-3: fpc0 PE Chip:PE-1[1]: EPW: eprq_map_disabled error" syslog message is seen in QFX Series devices and whether any action must be taken to resolve the error.

Symptoms:

The following error and alarm are observed during link flap and when ports are disabled, and when the "power low alarm" is set.

Reference Log

%PFE-2: fpc0 qsfp-0/0/12 Chan# 2: Rx power low alarm set
%PFE-2: fpc0 qsfp-0/0/12 Chan# 2: Rx power low warning set
%PFE-2: fpc0 qsfp-0/0/12 Chan# 2: Rx loss set
%PFE-3: fpc0 PE Chip:PE-1[1]: EPW: eprq_map_disabled error
alarmd[3591]: %DAEMON-4: Alarm set: FPC color=RED, class=CHASSIS, reason=FPC 0 Major Errors 
craftd[3592]: %DAEMON-4:  Major alarm set, FPC 0 Major Errors     <<<<<< Major alarm

Cause:

In a link flap and port down scenario, the Egress Packet Writer (EPW) queues will be disabled as per ASIC recommendation. This is to flush the entire ingress/egress pipeline when a link goes down. These messages are, therefore, expected in such scenarios.

Similarly, these messages and the EPW error may also be seen in cases when there is no actual link flap and there is only a "power low alarm" set, which results in a Major alarm even if the status applies for a single interface.

Solution:

These are informational messages that are generated by the system. They are expected by design.

The Major alarm will be cleared as soon as the EPW error is cleared.

Reference Log

%PFE-2: fpc0 qsfp-0/0/12 Chan# 2: Rx power low alarm set
%PFE-2: fpc0 qsfp-0/0/12 Chan# 2: Rx power low warning set
%PFE-2: fpc0 qsfp-0/0/12 Chan# 2: Rx loss set
%PFE-3: fpc0 PE Chip:PE-1[1]: EPW: eprq_map_disabled error
alarmd[3591]: %DAEMON-4: Alarm set: FPC color=RED, class=CHASSIS, reason=FPC 0 Major Errors 
craftd[3592]: %DAEMON-4:  Major alarm set, FPC 0 Major Errors
%PFE-2: fpc0 qsfp-0/0/12 Chan# 2: Rx power low alarm cleared
%PFE-2: fpc0 qsfp-0/0/12 Chan# 2: Rx loss cleared
%PFE-3: fpc0 PE Chip:PE-1[1]: EPW: clear eprq_map_disabled error 
alarmd[3591]: %DAEMON-4: Alarm cleared: FPC color=RED, class=CHASSIS, reason=FPC 0 Major Errors 
craftd[3592]: %DAEMON-4: Receive FX craftd clear alarm message: color: Major class: 100 slot: 0
craftd[3592]: %DAEMON-4: Major alarm cleared, FPC 0 Major Errors     <<<< Alarm cleared

Note: This alarm will be moved to "Minor" status from Junos OS release 15.1X53-D68 /16.1 onwards.

Modification History:

2018-07-20: Note in Solution section modified to say that the alarm will moved to minor status from Junos OS release 15.1X53-D68 / 16.1 onwards. A few minor modifications (non-technical) made.

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