The only way we were able to remedy this is to turn of CDP completely, and install an aggregations switch (we used an MS425) in between the MX and the rest of the switches.  The LLDP still does not show correctly between the MX250 and the MS425 unless you use an API to pull the correct data from the MX.  It's really a function of the Meraki Dashboard not pulling the correct information, or not pulling information in a timely manner.   We have started moving away from the Meraki Dashboard in favor of API calls because we get much more accurate information than the Meraki Dashboard will ever give us.   I recommend not using the Meraki Dashboard, and build your own dashboard via API calls.  It is a lot of initial setup, but you'll pull less hair out than looking at inaccurate information in the Meraki dashboard. ... View more