Adding to Paul comments.
1. Do you have stable Internet connection.
2. How is your Internet connection Terminated to MX100.
3. If possible for monitoring Purpose, implment the device directly facing internet, keep running the pings on.
4. when the MX 100 stop serving the check the monitor device is the internet also go down ?
other side. Do you see any Logs in the Meraki Dash board. You can see also Dash board what time the device gone offline so you can easily keep eye on the issue those timings ( if random then you need to rely on the device kept for monitoring)
by the way what is the Current version MX100 running ?
