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centosbandwidthtrafficnetwork-trafficmrtg

MRTG Graph and Bandwidth more than > 120 Mbps

H i ,

I've been experiencing that with MRTG .. the bandwidth not goes larger than 120 Mbps, MRTG would not display it correctly
my servers 1Gb port speed, and I download and upload by this speed, But MRTG graph not shoving traffic more than 120M.
Please, has anyone experienced this? can somebody help?

http://oss.oetiker.ch/mrtg/

Thanks.

Solution

  • This is a common problem caused by 16-bit counter rollover.

    If you are polling your device every 5min (the default) using SNMPv1, then a traffic greater than 120Mbps will cause the 16bit counter to wraparound in this time window. Hence, MRTG only displays the lower traffic as it cannot tell how many times the counter has rolled over.

    You have two options:

    1. Use SNMPv2. This is the best option, if your device supports it (most do). If using SNMPv2, then you can use the 64bit counters, which will not wrap around. To do this, add ':::::2' as a suffix to your Target definition to specify SNMPv2. Eg:

    Target[ezwf]: 1:community@router:::::2

    1. Increase polling frequency. You can change your polling to every 1 minute using 'Interval:1' , which increases your capacity by a factor of 5. However, note that this will require you to delete your old rrd or log file and recreate it; also you will need to deal with any changes to your scheduling method, and all Targets will use the same polling frequency.

    MRTG documentation is available at http://oss.oetiker.ch/mrtg/doc/mrtg-reference.en.html and covers the SNMPv2c target syntax as well as the changes in interval.