However, NAT loopback/reflection on the VIP, meaning internal client hits public IP of VIP which then loops back into internal server, gets offloaded.
Current theory is either the NAT reflection bypasses additional VIP processing, or the NPU acceleration applies only when traffic involves 2 internal ports (including FortiSwitch), so external public IP to WAN port public IP doesn't count.
However, NAT loopback/reflection on the VIP, meaning internal client hits public IP of VIP which then loops back into internal server, gets offloaded.
Current theory is either the NAT reflection bypasses additional VIP processing, or the NPU acceleration applies only when traffic involves 2 internal ports (including FortiSwitch), so external public IP to WAN port public IP doesn't count.