1 Reply Latest reply on Jul 13, 2014 8:31 PM by Hesh

    Interface Last Status Change Report Time/Date Problem

    geeper

      Hi, I am experiencing a problem with my Interface Last Status Change Report. It returns incorrect Date/Time values. I found the following info regarding this problem:

       

      Last Change date in Realtime Interface Monitor is in the future 

       

      The Last Change field uses two OIDs to attain it's value:

      -ifLastChange(1.3.6.1.2.1.2.2.1.9): This static value reflects the value for sysUptime when the interface's Operating Status changed. For example, if the interface's operating status changed 60 seconds after the device was rebooted, the ifLastChange value will be 600 (hundredths of seconds) until the operating status changes again.

      -SysUptime(1.3.6.1.2.1.1.3): This value represents the amount of time in hundredths of seconds that the system has been up.

       

      In order to calculate the Last Change value for the interface, ifLastChange is deducted from SysUptime. This gives us the amount of hundredths of a second since the change. We then compare that to the current date and time and we end up with the specific date and time of the change.

       

      The limitation of this calculation is that SysUptime rolls over at 4,294,967,296 hundredths of a second. When this occurs, deducting ifLastChange from SysUptime results in a negative number, which then ends up as a futuristic date.

       

      The only way around this is to reboot the device, which will reset all counters to 0.


      I would like to know if anybody has discovered a solution to this without rebooting the Switch, as that is not an option I have in my network environment.

       

      Looking forward to any replies that might be helpful.

        • Re: Interface Last Status Change Report Time/Date Problem
          Hesh

          I too would like an answer regarding this function as I am also experiencing incorrect timings.  I have switchports that have been in the "Down" state for several years (switch has been up for 4 years plus) and I have just administratively shut the ports down.  The "Last Change" counter is stating its last change was back in 2010!??  The Syslog is correctly reporting that the port has changed state but that is useless to me.

           

          I require accurate reports for capacity management so this function is a necessity.

           

          Hopefully this will get "bumped" to the top of the queue again and someone might be able to assist?

           

          Thank you

          Hesh