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Tail dropped packets

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  • 1.  Tail dropped packets

    Posted 06-20-2017 01:08

    Hello.

     

    I noticed some tail dropped packets on one of my interface on MX960.

    Queue: 1, Forwarding classes: C2
      Queued:
        Packets              :          221452493724                163821 pps
        Bytes                :        45170152624024             249068288 bps
      Transmitted:
        Packets              :          221452467949                163821 pps
        Bytes                :        45170120315215             249068288 bps
        Tail-dropped packets :                 21854                     0 pps
        RL-dropped packets   :                     0                     0 pps
        RL-dropped bytes     :                     0                     0 bps
        RED-dropped packets  :                  3921                     0 pps
         Low                 :                  3911                     0 pps

     

    I understand that RED-dropped packets are drops which occured on output queue of egress PFE, due to RED mecanism which start to empty the queue. But tail dropped packets is unclear for me. Does it mean packets which have been dropped by egress PFE, or does it mean packets dropped by ingress PFE, because egress PFE has applied backpressure to ingress PFE as it was not able to forward packets, due to output queue being full?

     

    Thanks for your help.

     

    Christophe



  • 2.  RE: Tail dropped packets
    Best Answer

     
    Posted 06-20-2017 01:19