Revising this old thread. I'm having the same exact issue when a client is behind a FortiGate firewall. Has there been any update on this? ... View more

Yes from wan interface/ip.   If you see traffic on the mx lan to meraki subnet/ports its most Likely  a AP or Switch management ip. ... View more

This solved my problem. The only way we could get the Meraki and the PPOE to play nice was to set the Userid and password for the PPOE, but leave IP address as Dynamic. ... View more

Your understanding is correct. ... View more