Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 
New Member

Monitoring ifInErrors with MRTG

I want to monitor in- and outgoing Errorscounter on any Switchports for some Catalyst 6506 and 4506 (CATOS and IOS) with MRTG.

Other monitoring with MRTG for bandwith and CPU utilization are working fine.

I have no practical idea which is the proper parameter for monitoring. If take the example of CPU monitoring that don't work.

I tried it with follow counter from RFC1213 MIB: ifInErrors and ifOutErrors.


Re: Monitoring ifInErrors with MRTG

So you're saying that ifInError/ifOutErrors give you zero output?

New Member

Re: Monitoring ifInErrors with MRTG

We monitored a port with errorcounter. MRTG gave us zero output.


Re: Monitoring ifInErrors with MRTG

DId you verify that the MRTG is stetup properly?. I'm not seeing all zeros on my switch.

New Member

Re: Monitoring ifInErrors with MRTG

If you do not specify the data type in the config file, MRTG assumes that the data type is counter. This means that MRTG will get the value of the object, in your case the error count. It will then run again and grab the error count again. As the error counter only grows, MRTG will take the value received and subtract the previous value to figure out what value to store. For example, if your error counter was 876 and five minutes later was 976, MRTG would graph 100. Thus, if you are graphing an error counter that is not actively increasing, you will always see a value of 0. If you want to have the actual value graphed, put "Option: guage" in the options for that graph.

New Member

Re: Monitoring ifInErrors with MRTG

I tried it with this configuration. Would you kindly inform me whether is that the right configuartion for monitoring the errorcounter with MRTG.


YLegend[Errorsit-develop01]: InErrors/Sec

ShortLegend[Errorsit-develop01]: sec

Legend1[Errorsit-develop01]: Errors per second

Legend2[Errorsit-develop01]: Errors Max value per interval on graph

LegendI[Errorsit-develop01]: Errors

Options[Errorsit-develop01]: unknaszero

Colours[Errorsit-develop01]: GREEN#00eb0c,BLUE#0000ff,GRAY#AAAAAA,VIOLET#ff00ff

SetEnv[Errorsit-develop01]: MRTG_INT_IP="" MRTG_INT_DESCR=""

MaxBytes[Errorsit-develop01]: 12500

Title[Errorsit-develop01]: Traffic Analysis for it-develop01, port 6/42


Traffic Analysis for device1, port 6/42

New Member

Re: Monitoring ifInErrors with MRTG

This looks correct, but you will only see errors if the error counter is actively increasing. MRTG treats all values as counters (think of a car's odometer). If you look at your odometer once and it reads 1000 miles and you look at it again five minutes later and it reads 1005, you don't really want to display 1005. You want to display 5, which is the difference between the two values. Hence, you drove 5 miles in those 5 minutes.

If you want to see the total number of errors on the link, change the options line to "Options[Errorsit-develop01]: unknaszero, gauge". This will graph the error counter as if it were like a speedometer. When you look at a speedometer, the value you see is what you want to graph. At your first data point it may be 15 mph. Five minutes later, it might be 55. The value of 55 is what you want, not 40 (55-15).

You most likely want to graph the Error Counter as you have it; however, to ensure that it is working correctly, you either have to wait for the counter to increase or try the gauge option. Once you have verified it, change it back to a counter.

CreatePlease to create content