Final answer:
The student's question pertains to the fragmentation of an IPv4 packet. The original packet would have certain fields like Total Length, Fragment Offset, More Fragments flag, and Identification. The packet will be divided into three fragments, each carrying a portion of the original data along with a modified header to ensure proper reassembly at the destination.
Step-by-step explanation:
The student has asked about the IP fragmentation process for an IPv4 packet that needs to be divided into three fragments. In IPv4, packets can be fragmented when they exceed the Maximum Transmission Unit (MTU) of the network segment being traversed. When a packet is fragmented, several fields in the IPv4 header are modified to handle reassembly at the destination.
For the original packet with a data payload of 700 bytes and destination address X.Y.Z.W, source address A.B.C.D, some values that can be provided are as follows:
- Total Length: Would be 700 bytes of data plus the header length, typically 20 bytes for a header without any options, so 720 bytes in total.
- Fragment Offset: For the original packet this will be 0, because it's the first (and originally unfragmented) packet.
- More Fragments (MF) flag: This would be set to 1 (true) since there will be more fragments after the first one.
- Identification: A unique value to help the receiving system reassemble the fragmented packets correctly.
Additionally, each of the three fragments would have specific changes related to the Fragment Offset and the MF flag. The first two fragments would have the MF flag set to 1, while the last fragment would have it set to 0. The fragment offset would be set incrementally in multiples of 8 bytes (64 bits).
Note: In the case where the data payload must be divided into fragments with up to 258 bytes each, the specified segments would likely have individual headers leading to the fragmentation of the 700-byte payload into segments that are a combination of data and additional IP header bytes.