When you go go Security & SD-WAN > Appliance Status there's a bar that shows the connectivity of your MX over time. With the drop-down you can make it show the data up to a month back.   There's also an alert you can setup for an MX going offline. But unfortunately it only allows a minimum downtime of 5 minutes before the alert is triggered. This and other alerts can be found in Network-Wide > Alerts.    You may also want to look into Meraki Insight. It has a feature called WAN health: https://meraki.cisco.com/blog/2018/10/new-for-meraki-insight-wan-health/ ... View more