Cisco Cisco Web Security Appliance S670 Guida All'Installazione

Decide how you are going to configure the Cisco S190 Web 
Security Appliance within your network.

The Cisco S190 appliance is typically installed as an additional 
layer in the network between clients and the Internet. 
Depending on how you deploy the appliance, you may or may 
not need a Layer 4 (L4) switch or a WCCP router to direct client 
traffic to the appliance. 

Deployment options include:

Transparent Proxy—Web proxy with an L4 switch

Transparent Proxy—Web proxy with a WCCP router

Explicit Forward Proxy—Connection to a network switch

L4 Traffic Monitor—Ethernet tap (simplex or duplex)

Simplex Mode: Port T1 receives all outgoing traffic, 
and port T2 receives all incoming traffic.

Duplex Mode: Port T1 receives all incoming and 
outgoing traffic.

To monitor true client IP addresses, the L4 traffic 
monitor should always be configured inside the firewall 
and before NAT (Network Address Translation).