Nexus PIE report shows "Laser is not enabled" on flapped port

[Petar Rusev]

Hello everyone,

We have two 400G links flapping and I am trying to find a reason why. 

I am trying to understand the meaning of "show pie eventdb link-down-rca detail" report.

What the report says is: 

Reason: Software Bug. Laser is not enabled.
Link Down Reason :Software Bug. Laser is not enabled. 

Do you think it is actual NX-OS SW bug or some QSFP mis-compatibility? 

This report is from 93600CD-GX, running 10.3.3F

[marce1000]

  - You may find this informative  : https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwi71532
                                                    although this one won't help
     + Also issue the command Switch# show interface  <interface name> transceiver details
look at the Transmit Fault Count , if available 
     + Look at the interface counters
     + Make sure all connections are solid
     + Check logs on the nexus : preferred = using a syslog server for connecting logs because then you have an easier access
                                                                   to review logging in time
     + Try another SFP('s) if available

    M.

[Petar Rusev]

Thank you for the information marce1000. Do you have any experience with the command suggested in the bug ID? 

I find information about it so far only in the N7K command reference guide:
Cisco Nexus 7000 Series NX-OS Interfaces Command Reference - S Commands [Cisco Nexus 7000 Series Switches] - Cisco

For 9Ks, I was only able to find it in 10.4.x configuration command reference guide, but only in the section New Commands:
Cisco Nexus 9000 Series NX-OS Command Reference (Configuration Commands), Release 10.4(x) - New, Changed, and Deprecated Configuration Commands [Cisco Nexus 9000 Series Switches] - Cisco

I will test it in the lab and share what's the outcome.

[marce1000]

         > Do you have any experience with the command suggested in the bug ID? 
  - No , I am not using the product myself , only doing support ; you may try it :
                   system default link-fail laser-on
    But according to the bug report it doesn't work

     - Personally  I would chose for the upgrade to https://software.cisco.com/download/home/286325342/type/282088129/release/10.3(5)
       (possibly benefiting from other bugfixes and it it an advisory release)

     +  Then check output from show pie eventdb link-down-rca detail
         again and check if the bug condition is still reported (or not)

 M.