Hello @Chris-L, If the switch is going offline at regular intervals, it may be due a failed firmware upgrade. A failed firmware upgrade will cause a device to go offline at regular intervals while it continuously tries to complete the upgrade. Is the MS120 reporting "Not running configured version" under firmware, as seen in the example attached?     If the firmware appears up-to-date, it may be a DNS or IP conflict issue causing the switch to fail Connection Monitoring tests on the uplink. Providing the detailed configurations will help to scope the issue, as alemabrahao has mentioned. Best, Feli ... View more