MS390 stack unreachable. Unable to reboot from dashboard.

[Flembot]

We have two MS390s which on Friday, randomly started to show as "unreachable" in our Meraki Dashboard. However, the entire site is online and the status light is a solid white light on both of those switches.

This is the first time this has happened and the switches have remained on the same firmware version since October/November 2022.

What can be the cause of this? 

Unable to reboot from Meraki dashboard as it thinks the switches are offline.

Should I reboot them in person when I am next on-site by removing their power supply for 30 seconds and then reconnecting them? 

Would really appreciate any advice on how to go about looking into this issue properly.

Our 390s are locked to beta FW version 15.14.2

Should probably update the firmware soon. Need to reach out to Cisco support to remove the firmware lock. But presumably, I'd need to resolve the connectivity to the switches first.  

Thanks in advance. 

[Brash]

Have there been any recent changes on the upstream firewall?

If you go to help -> firewall info, do you seen any failures in the firewall test results?

[PhilipDAth]

>What can be the cause of this? 

Software bug.

>Should I reboot them in person when I am next on-site by removing their power supply for 30 seconds and then reconnecting them? 

Yes.

[BlakeRichardson]

Probably a good idea to replace these sometime soon, this model doesn't have a good reputation.