I'm trying to update my firewall rules per the guidelines posted here: https://documentation.meraki.com/zGeneral_Administration/Other_Topics/Cloud_Maintenance_FAQ.
I've double-checked the rules, but can't seem to get rid of the warnings in the Meraki dashboard.
* This shows up at the top of my screen when I log in: "As part of ongoing efforts to improve the performance and resiliency of the Meraki Cloud we will be changing the IP addresses used by Cisco Meraki devices to contact the Meraki Cloud. One or more of your Meraki devices are unable to communicate with this new IP range. For more information about this upcoming change and how to resolve the connectivity issue, please click here."
* Also, when I look at the Appliance status, there's a warning that says: "Unable to fetch configuration
I find frequently that the Meraki dashboard falsely reports a lack of access to the new IP address ranges.
Also, once the alert is triggered it keeps getting displayed, even when you have resolved the issue. So you need to clear the alert by clicking on the right little cross in the top right hand corner.
I had the same issue, with the exception of im behind a Merak MX 100!
i asked support to identify what device was complaining, it was one random switch while the rest of my environment was fine. i went and rebooted it and the dashboard notice went away about a day later.
Support also gave me the same response but, like you i know our ISP isn't blocking anything. I suspect its a bit of a bug in the MS software.