For data packets whose length exceeds the MTU of the interface, fragmentation processing is required. The fields related to fragmentation in the IP header are as follows:

Identification - Used to confirm whether different fragments belong to the same IP packet.
Flags - where IP_MF indicates that there are also fragments, which are intermediate fragments.
Fragment Offset - Represents the offset address of this fragment in the entire message.

I have a question, how to understand the Flags is IP_MF, what will happen? is the IP fragmentation which flags = IP_MF will be divide to other fragmentations(I call it sub-fragmentation)? If is, how can the sub-fragmentation relate to the IP fragmentation which flags = IP_MF?