The return-to-sender feature eliminates unnecessary network traffic when the three following conditions are met:
- The ProxySG has connections to clients or servers on a different subnet.
- The shortest route to the clients or servers is not through the default gateway.
- There are no static routes or RIP routes defined that apply to the IP addresses of the clients and servers.
Under these conditions, if the return-to-sender feature is enabled, the ProxySG remembers the MAC address of the last hop for a packet from the client or server and sends any responses or requests to the MAC address instead of the default gateway.
For more information about the return-to-sender feature, including the CLI syntax, please refer to #(config) return-to-sender in the CLI Reference guide. The CLI reference guide is available at https://bto.bluecoat.com/ for the version of SGOS running your ProxySG.