Ideally for the primary circuit get a fibre circuit with a /29 of address space.  Plug both MX's into this.  As a compromise you could get a circuit that comes with a single public IP address and an ISP router and plug both MX's into that.  This is more painful if you want to do inbound NAT - otherwise it is a price sensitive compromise.   You have the same options for the secondary circuit.  You also have the option of only plugging it into the primary MX.  If the primary MX fails the secondary MX will take over, and all traffic will only go out the primary WAN circuit.   Use a VLAN for WiFi, and another VLAN for everything else.  Then use flow preferences to route one VLAN out the primary circuit, and the other VLAN out the secondary circuit.  Everything will be able to failover if something dies. https://documentation.meraki.com/MX/Firewall_and_Traffic_Shaping/MX_Load_Balancing_and_Flow_Preferences#Flow_Preferences ... View more