On the ASA you are unable to ping an Interface IP if the icmp traffic comes in via another interface. This is by "design"
Is this also a design of the Meraki MX appliances? I haven't managed to test this yet.
I'm "hoping" I can send a ping to the MX Internet / WAN address but the source of the ICMP would be from a LAN device behind another interface on the MX.
(Correct routing would all be in place).
There is a specific reason I am looking for this ability 🙂