OK this aged like milk 😉 ... View more

These switches support EAP and MAB (radius without EAP session). So you need to integrate your radius server with the switches. ... View more

You can use a 3/4G USB modem, however, your mileage may vary and the support for these is now "best effort" as explained here: https://documentation.meraki.com/MX/Cellular/3G%2F%2F4G_Cellular_Failover_with_USB_Modems   USB modems with MX/Z series devices running firmware MX 18 or newer will be limited to best effort support and will not be receiving any future firmware fixes or improvements.    As @PhilipDAth, you're better off using an MG or other cellular gateway (Ethernet) plugged into the secondary WAN.  ... View more