dns.google being blocked and lots of dropped events

[LakesideLion]

Hello Meraki Community,

We're new to the Meraki gear and are slowly but surely migrating our entire network.  So now learning the nuances of our MX450.  First thing I can't really find an adequate explanation for is this.   I was looking in our event logs and we're getting thousands of content filtering events related to blocking dns.google.  We're also getting thousands of dropped events.

How do we get rid of those.  It doesn't seem like we're getting blocked from Google DNS as no one has reported any problems accessing anything.  All these events are just clogging up the event log.

[ww]

In case you are using content filter, DoH and DoT (proxy avoidence? in 16.x fw). It could block dns requests on port 443 and only allow on port 80.

Most internet browsers try first on port 443 and then fall back to 80

[LakesideLion]

Thanks for the info.  We do have the proxy avoidance filter being used.  We're trying to monitor and block students from getting around our content filtering.  If the MX is really blocking DoH and DoT then shouldn't everybody not be able to get to any website?  I'm going to have to review how DNS works again.  I thought I understood it.