I've just done some tests.  The MS225-48LP refreshes the values every 30 seconds, and the MX84 (the only model I have to test) does it every 60 seconds.  I set up PRTG to poll the MX every 65 seconds as I was still getting some zero-values in there.  Fundamentally, this needs vast improvement.  The box itself should write these to these values every 5 seconds like Cisco Catalyst switches.  You are able to capture the peaks and produce a much smoother graph.  While the Dashboard provides ease of use and configuration, much of the time, I find the specifics and granularity a little wanting.  I've deployed probably over 1000 Meraki devices, and I do like the technology, I just wish it had better telemetry capability. ... View more