Different graphs between MRTG and CACT

Question

Hi guys I need your help, in a few words I have one node installed in CACTI and MRTG but after few months I saw and my graphs is not working properly en MRTG. Why I have this big different? Attached the logs.

Thanks I hope you can help me.

Logs: CACTI and MRTG graphs

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Regards Luis

Answer 1

It is hard to tell without seeing the configuration for both your MRTG and Cacti metrics that are being graphed. Presumably you are expecting the two graphs to look identical?

It is possible that the lower values for Inbound being seen in the bottom graph are caused by counter wraparound. To avoid this, you need to ensure that your MRTG does one of the following

• Poll every minute rather than every 5 minutes (the default)
• Use SNMPv2 32bit counters, so that there is no wraparound.

You should also do the obvious checks i.e. verify that both are really graphing the same item, at the same polling frequency, averaged over the same intervals, etc.