I have the Thresholds module (0.4.2) installed for Cacti (Cacti Version: 0.8.7g, Plugin Architecture Version: 2.9) but I can't figure out which settings I need to use, to make a threshold alert, for a sudden drop in link utilisation.
I want to be alerted if a link drops by say 50% within 5 minutes. So the link is polled, it's running at say 75%, 5 minutes later when its next polled, if it's dropped to 5%, I want to know about it.
How can this be done? I have been trying with the "Baseline" threshold type as this seems the most appropriate but it's alerting me all the time so I've obviously not understood.
Many thanks for your time.