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nmcap dropped fames statistic wrong? RRS feed

  • Question

  • Hello,

    I am trying to determine if my nmcap is dropping frames. This is pure capture with no filtering, writing to chained files. Nmcap starts fine and reports no dropped fames but at some point (hours later) is starts reporting dropped frames. Looking at the nmcap status line: Capturing | Recvd: x Pending: y Dropped: z | Time: deltaT.

    This morning after letting it run over night I compared the numbers after 60s. So subtracting the Rcvd, Saved and Dropped numbers I get: 1,230,131 Rcvd, 1,230,131 Saved and 8,291,446 Dropped. The Dropped number makes no sense to me. Bug?

    -Wes

    Thursday, November 1, 2012 5:31 PM

All replies

  • Hi Wes,

    The dropped number reporting should be what's reported up through our system.  It's probably accurate and actually dropping frames.  You could have hit your Disk Quota settings (you can view those in the Network Monitor UI).

    You might also want to check if Conversations are Disabled as that'll cause Memory to grow and could be causing some other issue.

    Thanks,


    Michael Hawker | Program Manager | Network Monitor

    Friday, November 2, 2012 9:35 PM
    Moderator
  • Michael,

    I have lots of disk and conversations are disabled. But all that aside consider the numbers. In 60 seconds I recvd 1.2 million frames and saved 1.2 million frames while in the same 60 seconds I dropped 8.3 million frames. That doesn't make any sense, how can I drop more frames that I received. Clearly must be a bug.

    -Wes

    Sunday, November 4, 2012 10:28 PM
  • Hi Wes,

    The dropped number is a combination of various values including values from the network device, our driver and the capture engine.  It's possible that frames were dropped before they were 'received' by the capture engine.  So, this could be alright.  It's really hard to tell what's going on without playing with a few more knobs and getting some more data.

    Thanks,


    Michael Hawker | Program Manager | Network Monitor

    Monday, November 5, 2012 7:26 PM
    Moderator