Transparent interception with a Layer 4 switch

Layer 4 switches can redirect supported protocols to the proxy, while passing all other Internet traffic directly to its destination, as shown below for HTTP.

Layer 4 switches offer the following features, depending on the particular switch:

• A Layer 4 switch that can sense downed hosts on the network and redirect traffic adds reliability.
• If a single Layer 4 switch feeds several proxy servers, the switch handles load balancing among the Content Gateway nodes. Different switches might use different load-balancing methods, such as round-robin or hashing. If a node becomes unavailable, the switch redistributes the load. When the node returns to service, some switches return the node to its previous workload.
  Note: It is recommended that you do not enable Content Gateway virtual IP failover when a switch is providing load balancing in a cluster configuration.