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QFX5200-32C VirtualChassis snmp counters not increased for jnxVirtualChassisPortInCRCAlignErrors

  • 1.  QFX5200-32C VirtualChassis snmp counters not increased for jnxVirtualChassisPortInCRCAlignErrors

    Posted 29 days ago

    Hi everyone.

    We have a 3-member VC out of 3 x QFX5200-32C running JunOS 22.2R3-S3.18. After an outage caused by a faulty VC-Port cable (generating a lot of CRC errors), we turned our attention to adjust monitoring to catch this. After having enabled vcp-snmp-statistics, we saw entries under jnxVirtualChassisPortTable get populated. However, we also noticed that one particular metric we were interested in, did not get updated correctly:

    root@vpc01> show snmp mib walk ascii jnxVirtualChassisPortInCRCAlignErrors     
    jnxVirtualChassisPortInCRCAlignErrors.0."vcp-255/0/28.32768" = 0
    jnxVirtualChassisPortInCRCAlignErrors.0."vcp-255/0/29.32768" = 0
    jnxVirtualChassisPortInCRCAlignErrors.0."vcp-255/0/30.32768" = 0
    jnxVirtualChassisPortInCRCAlignErrors.0."vcp-255/0/31.32768" = 0
    jnxVirtualChassisPortInCRCAlignErrors.1."vcp-255/0/28.32768" = 0
    jnxVirtualChassisPortInCRCAlignErrors.1."vcp-255/0/29.32768" = 0
    jnxVirtualChassisPortInCRCAlignErrors.1."vcp-255/0/30.32768" = 0
    jnxVirtualChassisPortInCRCAlignErrors.1."vcp-255/0/31.32768" = 0
    jnxVirtualChassisPortInCRCAlignErrors.2."vcp-255/0/28.32768" = 0
    jnxVirtualChassisPortInCRCAlignErrors.2."vcp-255/0/29.32768" = 0
    jnxVirtualChassisPortInCRCAlignErrors.2."vcp-255/0/30.32768" = 0
    jnxVirtualChassisPortInCRCAlignErrors.2."vcp-255/0/31.32768" = 0
    
    {master:0}
    root@vcp01> show virtual-chassis vc-port statistics extensive | match "CRC"    
    CRC alignment errors:      0            
    CRC alignment errors:      0            
    CRC alignment errors:      0            
    CRC alignment errors:      0            
    CRC alignment errors:      0            
    CRC alignment errors:      0            
    CRC alignment errors:      1384         
    CRC alignment errors:      0            
    CRC alignment errors:      0            
    CRC alignment errors:      0            
    CRC alignment errors:      0            
    CRC alignment errors:      0    

    I normally would have opened a TAC case, but unfortunately the setup doesn't allow us. We rent the switches from the datacenter provider and because we choose to manage them ourselves in terms of config, they have refused to open a TAC case on our behalf (we're working on better terms). 

    Few questions around this issue:

    1. Have we missed something in config? This really looks like a bug more than anything else, considering other counter like jnxVirtualChassisPortInPkts increase correctly.
    2. Provided we manage to address the issue, how can we test that the CRC counters are increasing correctly? In other words, how can we simulate CRC errors and validate the fix?


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    ANDREI NEAGOE
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