Direct routing | Forwards the source and destination IP addresses with no changes. When Direct routing is selected, the IP address of the virtual server is the same as the back-end server’s address. The back-end server replies directly to the client, either through FortiADC or directly, depending on the configuration. |
NAT | Replaces the destination IP address with an IP address from a pool of IP addresses that you define. The destination IP address of the initial request is the IP address of the virtual server. Configure FortiADC as the default gateway on the back-end server to ensure the reply goes through FortiADC. |
FullNAT | Rewrites both the destination and source IP addresses. The source IP address is replaced by an IP address from the pool you define using Server Load Balance > Resources > IP Pool. The destination IP address is replaced with an IP address from a pool of IP addresses that you define. |