stealth bridge to filter traffic within same LAN segment

Hi,

I'm new to Fortigate, and I'd like to set up a really simple bridge.

Suppose I have a LAN switch with hosts within 192.168.0.1-10. I then connect a Fortigate between this switch and another. On the second switch I have hosts 192.168.0.11-20.

I want these two groups of hosts to be able to connect to each other through the Fortigate (so I can see all sessions).

So imagine I connect switch1 to port WAN1 or LAN Port 1 on the Fortigate, and  switch 2 to WAN2 or LAN Port 2 (whichever).

I then add IPv4 policies so I "accept all" traffic:

1) from WAN1 to WAN2

2) from WAN2 to WAN1

3) from Port1 to Port2

4) from Port2 to Port1

I also want to configure the management interface with IP addr. 10.1.1.1/16. It is physically connected to another switch/network.

I supposedly have it all configured, but I see no traffic flowing between both interfaces (WAN* or Port*).

Can anyone please give me some genral pointers (or CLI commands) to make this happen?

It basically needs to be a transparent bridge within the same suibnet so I can analyze/filter traffic.

Thanks,

Vieri

[EDIT] Please find attached several screenshots. WAN1, WAN2, Port1 and Port2 are configured alike. I would like to bridge any set of WAN1+WAN2 or port1+port2. Then simply monitor traffic flowing within this or these bridge/s.

[EDIT] Virtual Wire Pair... is that the way to go?