To configure the appliance for IPS Sniffer Mode, use two interfaces in the same zone for the L2 Bridge-Pair. You can use any interfaces except the WAN interface. For this example, X2 and X3 are used for the Bridge-Pair and are configured in the LAN zone. The WAN interface (X1) is used by the firewall for access to the firewall Data Center as needed. The mirrored port on the switch connects to one of the interfaces in the Bridge-Pair.