Due to NP6 internal packet buffer limitations, some offloaded packets received at a 10Gbps interface and destined for a 1Gbps interface can be dropped, reducing performance for TCP and IP tunnel traffic. If you experience this performance reduction, you can use the following command to disable offloading sessions passing from 10Gbps interfaces to 1Gbps interfaces:
config system npu
set host-shortcut-mode host-shortcut
host-shortcut to stop offloading TCP and IP tunnel packets passing from 10Gbps interfaces to 1Gbps interfaces. TCP and IP tunnel packets passing from 1Gbps interfaces to 10Gbps interfaces are still offloaded as normal.
host-shortcut is set to the default
bi-directional setting, packets in both directions are offloaded.
This option is only available if your FortiGate has 10G and 1G interfaces accelerated by NP6 processors.