I have a site that has reported network outages yesterday but my network supplier claims that they've seen no outage.

The site has a 2218P as its primary switch connected to a Fortigate 40F.  Daisy-chained off the 2218P are 2 SG2008 (Hware 4.20 and Fware 4.20.9) switches in different parts of the building.

Centrally, we have an OC300 controller and all switches are adopted on to that controller.  Firmware 1.30.7.

The site says they had no power issues.

Between 4pm yesterday and 2pm this morning, all three switches show gaps in the statistics recorded, where no data has been recorded. These gaps appear to correspond with the network outages that the site has reported.

Looking at 5 minute interval data, I see statistical data being recorded fine, then one or two records are missing and then there will be a single data 'blip' then a longer gap then the statistical record will restart.

If there was an Internet connection issue, I would still expect to see traffic on the switches - not blank gaps.

If there was a power issue in the main data cabinet, it wouldn't have affected the SG2008 switches as they are on a separate power circuit, but all 3 switches show the same blank gaps.

If the switches had reset - then I would assume that the config would have been lost but all three switches seem fine, config remains the same.

What am I missing?  Has anybody seen any similar issue?

Thanks