Problem about Tse loop back .

I use sgdmatx Tse sgdmarx test system. Tse set 32bit boundary loop back . I can receive data .for example. Tx data is Ethernet frame 00 00 ff ff ff ff ff ff ...... Receive data is 00 00 ff ff ff ff ff ff ..... The two zero bytes of txdata is for alignment . My question is if I did not set loop back ,the two zero bytes will be sent to rgmii as part of frame data?