During fragmentation, where is the embedded protocol header stored?

During fragmentation, where is the embedded protocol header stored?

• A. In every fragment
• B. In the last fragment
• C. Not stored in fragments
• D. Only in the first fragment

Answer: (D)

During IP fragmentation, the upper-layer protocol header (such as TCP or UDP) is carried only in the first fragment. The subsequent fragments contain just portions of the payload and their own IP headers with fragment offsets, but they do not repeat the higher-layer header. When reassembling, the device uses the information from the first fragment to interpret the entire payload. This avoids duplicating the upper-layer header in every fragment and keeps fragmentation efficient.

During IP fragmentation, the upper-layer protocol header (such as TCP or UDP) is carried only in the first fragment. The subsequent fragments contain just portions of the payload and their own IP headers with fragment offsets, but they do not repeat the higher-layer header. When reassembling, the device uses the information from the first fragment to interpret the entire payload. This avoids duplicating the upper-layer header in every fragment and keeps fragmentation efficient.