FortiGate port monitor from Cisco

[acalvo]

Hello,

We're planning to replace our current firewall (Cisco ASA) for a FortiGate 100D, and the first step would be to put the FortiGate in learning mode to see what kind of traffic flows through the network.

Our current L3 router is a Cisco SG500-52P stack, and our network is separated using several VLANs.

FortiGate already has dedicated point-to-point networks to connect to the ISP, old FW and L3 router -- although all routing still goes thru the old setup from the L3 router.

In addition to that, port monitoring by VLAN has been enabled on the L3 router to mirror all traffic to the FortiGate; however, when the interfaces are up all communication to the FortiGate is lost -- as it might create a loop since some packets enter from the monitor interface and try to be routed to the point-to-point interface.

Would it be possible to have the monitor port on the FortiGate just to learn/analyze traffic but not process/route it?

Thanks