Hello. I am deploying a firewall using the 5.6 firmware, and I have a weird issue. I have 2 smart switches that need to connect to the fortigate, as trunk ports. They both use the same IP'd VLANs, say 10, 20, and 30.

When I attach the VLANs to the a single interface, say Internal7 on a 60D, everything works, and I can plug either switch in and get communcation.

This is where it gets weird.

If I try to make a software/hardware switch, and attach the vlans to it, so I can use more than 1 physical port, weird stuff happens. Devices down the trunk can get DHCP from the firewall, but the firewall won't talk to the devices down stream and things aren't reachable. For example - I can ping a device on he VLAN 10 network when using a single interface, but I cannot ping it when using a switch.

I am banging my head on a wall here, is anyone familiar with how to do this.

TLDR - How do I configure a FWF60D to use 2 trunk ports for the same VLANs, so I can plug 2 smart switches into the fortigate?