You can use the vswitchmode datalink property to control switching between VMs over the same physical port. The three possible values are:
local – Enables the network traffic between VMs over the same physical NIC to be exchanged internally. This is the default mode.
remote – Enables the network traffic between VMs over the same physical NIC to be exchanged through the external switch.
auto – Uses LLDP to determine whether reflective relay is supported on the external switch. If reflective relay is supported on the external switch, network traffic between VMs is exchanged through the external switch. Otherwise, network traffic between VMs is exchanged internally.