When trying to send fragment packets, the "fragment offset" value should be right, or else DUT or wireshark can't reassemble the packets.
The unit of "Fragment offset" is 8 bytes.
So if the frame length of each fragment is 1514(without FCS), the data length in the IP packet is 1514 - 14(Ethernet Header) - 20(IP Header) =1480
"Fragment offset" of the second fragment should be 1480/8 = 185
So the value of "Fragment offset" be set in the STC should be 185 (For second fragment), 370(For the third fragment) and so on
Note : All fragments must have the same Identification field value in the IP Header.