Connect fortigate behind another fortigate

[RyanFItz]

What would be the best way to connect a fortigate behind another fortigate?

I have the ISP coming into the wan port on fortigate 1. I need to setup a sub tenant in that space with their own fortiagate that is going to share the isp connection. DMZ port? or proxy a public IP though the first fortigate? Or just do a switch on the ISP side and do IP block a to fortigate 1 WAN and IP block 2 to fortigate 2 WAN?

Firewall 1 needs to be completely isolated form firewall 2 but share the ISP connection coming into Firewall 1

[pmeet · Accepted solution]

If you need Firewall 1 needs to be completely isolated form firewall 2 but share the ISP connection coming into Firewall 1 then I would recommend the best approach here should be adding a switch to the ISP modem and connect both firewalls in it instead first connecting firewall 1 and under firewall 1 connecting firewall 2 , as in this set up you will might need to enable subnet overlapping on firewall 1

[RyanFItz]

Thats what I assumed, thanks