NAT in Routed Mode
The following figure shows a typical NAT example in routed mode, with a private network on the inside.
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When the inside host at 10.1.2.27 sends a packet to a web server, the real source address of the packet, 10.1.2.27, is translated to a mapped address, 209.165.201.10.
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When the server responds, it sends the response to the mapped address, 209.165.201.10, and the Firewall Threat Defense device receives the packet because the Firewall Threat Defense device performs proxy ARP to claim the packet.
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The Firewall Threat Defense device then changes the translation of the mapped address, 209.165.201.10, back to the real address, 10.1.2.27, before sending it to the host.