A method of adjusting fields of a datagram in the handling of the datagram in a network device is disclosed. The method includes receiving a datagram, with the datagram having at least module identifier fields and port identifier fields, at a port of a network device, determining whether the received datagram is a unicast datagram, adjusting the module and port identifier fields of the datagram based on data registers in the network device when the received datagram is a unicast datagram and forwarding the datagram based on the module and port identifier fields of the datagram. The port of the network device is connected to a legacy device, where the legacy device has a reduced handling capacity when compared to the network device.