OVS split-horizon logic will drop pkts by default if value of in_port and out_port is the same. But, if we have two vlan-trunk member VM for which trunk interface is same, the connectivity between these two VM cannot be established as OVS drops such packets. So, it is required to override the value of in_port so that split_horizon check is bypassed.

Nicra NXM_OF_IN_PORT support is required in order to achieve this. The in_port value will be overrriden using load.

Ex: load:0x1->NXM_OF_IN_PORT[]