Disabled switch (Bad DNS)

[AmitPanchal]

Switches are showing Disables switch (Bad DNS). Also checked the logs for loop but didn't get any.

The whole network is of Meraki switches.

[cmr]

From the switch can you ping the DNS server and can you lookup a host?  (On the tools menu)

[AmitPanchal]

Yes I am able to ping the DNS server. But the alert stays for only few minutes and during that period the whole internal network goes down.

[RaphaelL]

If the switch is reporting issues with DNS , there a chance that other things are failing during that period. 

https://documentation.meraki.com/General_Administration/Cross-Platform_Content/Alerts_and_Notificati...

I would take a packet capture if possible. 

What are the logs showing ?

[rdominguez]

Depending on how the network is configured, there can be a few conditions that would cause these alerts. If internal servers are being used, as opposed to something like 8.8.8.8 for management, the reachability to those servers would need to be checked when this is occurring. Packet captures, as already noted, would also be helpful in determining why the switches are alerting. 

[PhilipDAth]

What DNS server is being used, and what path should the device be taking to get to it?

What about your backup DNS server?

[BlakeRichardson]

If using internal DNS maybe have a public DNS server like 8.8.8.8 as a secondary if your network manager allows the use of external DNS on internal equipment / clients. 

If the DNS server is connected to a Meraki switch can you see the connection history of the port and are there any errors shown?

[AmitPanchal]

We are using 8.8.8.8 as our primary DNS server and 4.2.2.2 as secondary DNS server for all the network devices.

Also this alert is showing only for some switches.

[AmitPanchal]

Also if there's an DNS issue why I am not able to ping my internal network?