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.
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.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...