reveal connected WAN MAC address

[pcrequest]

Is there a way to see the MAC address of my ISP's upstream device?  I'd like to verify the manufacturer of whatever is plugged into the Internet ports of z3/mx68 etc.

Thanks.

[ww]

Take a short packet capture of the internet port.  You should see the meraki mac and one other mac (from the isp router)

[pcrequest]

Great idea, and thank you! I will definitely do this in other scenarios.  In this case, the z3 is in an orange state, and it won't allow a pcap. 

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

I learned through photos the wrong modem is hooked up! I've basically figured out my problem, but perhaps if I didn't have access to photos, is there another way besides a pcap to figure out the mac?  I'm guessing not.